Journal articles: 'Microhardness of steel'

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Stepanov, Makar S., Yuri M. Dombrovskii, and Levon V. Davidyan. "Microarc surface alloying of tool steels." MATEC Web of Conferences 226 (2018): 03007. http://dx.doi.org/10.1051/matecconf/201822603007.

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A new method of accelerating of steel diffusion saturation during thermo-chemical treatment – microarc surface alloying is proposed. The steel product is placed in a metal container filled with coal powder, and heated by passing an electric current. Powder having microarcs, which are concentrated around the surface of the product with the formation of zones of local gas discharge. This significantly speeds up the diffusion saturation. After carburizing of steel 20Cr13 is formed a diffusion layer thickness of 13-15 μm microhardness of 10.5 to 12.5 HPa, located below the eutectoid area a thickness of 300 μm and a hardness of 6.5 GPA. After boriding of steel Cr12V1 after standard heat treatment, the surface layer with a thickness of 170-180 μm consists of a base with microhardness of 9.3-9.6 GPA with inclusions of microhardness of 14.5-15.0 GPA. After boriding of steel 5CrNiMo formed a layer thickness of 250-260 μm with a composite structure consisting of sections of the eutectoid structure of microhardness of 7.0-8.0 GPA, surrounded by boride eutectic microhardness 12.0-12.5 GPA. The composite structure provides the combination of very hard boride eutectic and eutectoid plastic mixture. After boriding of steel W6Mo5Co5 after standard heat treatment, the surface layer thickness of 230-240 μm consists of a base of microhardness 11,0-11,2 GPA with inclusions of microhardness 13,5-14,5 GPA. Given the high intensity of diffusion saturation, microarc surface alloying is recommended for surface hardening of tool steels.

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Astashchenko, V. I., G. F. Mukhametzyanova, and A. G. Shagiev. "Criteria for Evaluating the Manufacturability of Steels when Cutting with an Edge Tool." Materials Science Forum 1052 (February 3, 2022): 62–67. http://dx.doi.org/10.4028/p-rim7y5.

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Comprehensive metallographic studies of steel forgings with different machinability by cutting with an edge tool were also completed. Structural features and properties of steel were revealed, having adversely influence on tool life and the process of chip formation during cutting. Metal Science criteria have been given for assessing the manufacturability of steel at machining operations. Microstructures of steel with satisfactory and unsatisfactory machinability are presented. The technological parameters of heat treatment of steel 18HGR have been established, causing a show of banding of ferrite-pearlite structure. The thermokinetic diagram shows an area of development of the segregation banding structure. An important role in assessing the manufacturability of steels is shown of the microhardness of individual structural components and the difference in values between them. The best results in machinability by cutting are observed when the microhardness of pearlite is not more than 350 HV, ferrite is not more than 210 HV and the difference in microhardness between these components is not more than 80 HV.

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Benkovsky, Yu V., D. M. Kroitoru, V. I. Petrenko, P. N. Stoichev, E. V. Yurchenko, and A. I. Dikusar. "Interrelation of the Composition of Steel Treated by Electrospark Alloying and the Properties of Obtained Composite Surface." Elektronnaya Obrabotka Materialov 58, no. 1 (February 2022): 1–8. http://dx.doi.org/10.52577/eom.2022.58.1.01.

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Basing on the study of the elemental composition of surface composites obtained on 45, 65G, and St3 steels by electrospark alloying using processing electrode from T15K6, VK8 hard alloys, as well as 45 and St3 steels (the “steel on steel” option), it was shown that the resulting surface layers are ~70% composed of the material steel substrate modified by electro-discharge treatment. The influence of the steel composition on the coefficients of the processing electrode material transfer on the substrate, on the roughness, microhardness, and wear resistance of the resulting surfaces has been studied. It is shown that the wear resistance of the resulting composites is determined mainly by the nature of the treated surface and, to a much lesser extent, by the processing electrode material, roughness, and microhardness of the surface.

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Kolařík, Ladislav, Miroslav Sahul, Marie Kolaříková, Martin Sahul, and Milan Turňa. "Resistance Spot Welding of Low Carbon Steel to Austenitic CrNi Stainless Steel." Advanced Materials Research 875-877 (February 2014): 1499–502. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.1499.

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The contribution deals with resistance spot welding of low carbon steel to austenitic CrNi stainless steel. The thickness of welded dissimilar steels was 2 mm. DeltaSpot welding gun with process tape was utilized for welding of the above-mentioned combination of steels. Resistance spot welds were produced under different welding currents. The welding currents used were 7 kA, 7.5 kA and 8 kA, respectively. Optical microscopy, microhardness measurement across the weld joint and EDX analysis across the weld joint interface were used to evaluate the quality of resistance spot welds of dissimilar steels.

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Hu, Min. "The Study on the Weldability of 1MnCrMoNi Alloy Steel and Q235 Carbon Steel." Key Engineering Materials 861 (September 2020): 71–76. http://dx.doi.org/10.4028/www.scientific.net/kem.861.71.

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In this paper, the weldability of 1mncrmoni alloy steel and Q235 carbon steel is studied. The microhardness, tensile strength, impact and other mechanical properties of the welded joint are tested by manual arc welding. The variation trend of microhardness, tensile strength and impact toughness of the welded joint under different welding methods is studied, which provides theoretical support for practical engineering application.

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Kucukomeroglu, T., and S. M. Aktarer. "Microstructure, microhardness and tensile properties of FSWed DP 800 steel." Journal of Achievements in Materials and Manufacturing Engineering 2, no. 81 (April 1, 2017): 56–60. http://dx.doi.org/10.5604/01.3001.0010.2038.

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Purpose: Dual phase (DP) steels are widely used in the automotive industry due to their properties of a high balance of strength and formability. However, it is known that conventional welding of high strength steel leads to some undesirable results such as hardness decrease in the heat affected zone. Friction stir welding (FSW) is a new solid state joining method, which is used to join these steels due to its advantage of low heat input. The aim of this study is to evaluate the microstructural change and mechanical properties of friction stir welded DP800 steel. Design/methodology/approach: DP 800 steels with 1.5 mm thickness were subjected to friction stir welding, by using a tungsten carbide (WC) tool. The tool was tilted 2°, and downforce of the tool was kept constant at 6 kN. During processing, the tool rotation and traverse speed were fixed at 1600 rpm and 170 mm∙min-1, respectively. Findings: The friction stir welded region comprises martensite, bainite, refined ferrite. The average microhardness of stir zone has increased from 260 HV0.2 to about 450 HV0.2. The tensile sample shows a decrease in the ultimate tensile strength (σUTS) about 3%, from 827 MPa to 806 MPa for the joint. The yield strength (YS) of the joint is about 566 MPa and the value is near that of DP800. Research limitations/implications: The tungsten carbide tool used for the friction stir welding has suffered deterioration in the pin profile after 1 meter welding operation. It may be advisable to drill a pre-hole in the specimens for a longer tool life. Practical implications: Tool wear for industrial applications will be a major problem. Therefore, the use of tools with high wear resistance such as polycrystalline cubic boron nitride may be recommended. Originality/value: Works on friction stir welding of dual phase steels are limited and they mostly focus on spot welding. Also, this study systematically investigates the microstructure and mechanical properties of dual-phase 800 steels after the friction stir welding.

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Ye, Jin Ling, and Feng Ye. "Effects of Strong Carbide-Forming Elements on Low Temperature Salt-Bath Chromizing." Advanced Materials Research 214 (February 2011): 646–50. http://dx.doi.org/10.4028/www.scientific.net/amr.214.646.

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The microstructure, phase structure, white layer thickness and chromium concentration, microhardness of the chromized layer of T10 steel and 3Cr2W8V steel by low temperature salt-bath chromizing with plasma nitriding are contrasted. The chromizing process is investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD). Results show that the strong carbide-forming elements (Cr, W, V) obstruct the diffusion of chromium and carbon, the white layer thickness and microhardness, surface chromium concentration of the chromized layer are reduced. A chromized layer of T10 steel with average 7.3μm in thickness, 84.47% in surface chromium concentration and 1300HV-1400HV in microhardness is formed on the substrate by chromizing at 610°C for 6h, as compared to the chromized layer of 3Cr2W8V steel with average 3.3μm in thickness, 74.27% in surface chromium concentration and 1200HV-1300HV in microhardness.

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Ji, Huiling, Yiwei Zhang, Wenzhao Lu, Bang Wei, and Xiaomin Yuan. "Effect of Hot Working Processes on Microstructure and Mechanical Properties of Pipeline Steel." Crystals 11, no. 8 (July 24, 2021): 860. http://dx.doi.org/10.3390/cryst11080860.

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The microstructure and microhardness of X70 pipeline steel were investigated after conducting different processing routes. The microstructure was characterized using optical and electron microscopy. Scanning electron microscopy equipped with electron backscattered diffraction (EBSD) and transmission electron microscopy techniques were applied for investigation of different thermal processing treatment conditions. Mechanical properties were characterized by a microhardness tester. The results show that the microstructure mainly consists of granular bainite, acicular ferrite and a small amount of M/A constituents under hot rolling states. There are many dislocations inside the acicular ferrite. The thermal simulation experiments show that the microstructure becomes homogeneous with the increase in cooling rate. The acicular ferrite morphology becomes fine and uniform, and the content of M/A constituents increases at the same compression amount. The compression gives rise to the accumulated strain and stored energy, which accelerate the transformation of acicular ferrite and refine the microstructure of the pipeline steel. The microhardness rises with the increase in deformation ratio and cooling rate. The microstructure of the pipeline steel subjected to the isothermal quenching process is ultrafine ferrite and M/A islands. When the isothermal quenching temperature reaches 550 °C, a small amount of upper bainite appears in the microstructure. With the increase in isothermal quenching temperature, the microhardness decreases. Acicular ferrite is a better candidate microstructure than ultrafine ferrite for the pipeline steels.

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Skakov, Mazhyn, Lyaila Bayatanova, and Michael Sheffler. "Changes of Structural-Phase Condition in 18CrNi3MoA-SH Steel After Elektrolyte-Plasma Processing." Advanced Materials Research 601 (December 2012): 74–78. http://dx.doi.org/10.4028/www.scientific.net/amr.601.74.

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The research shows the results of electrolyte-plasma treatment influence on structure-phase state, mechanical properties and wear-resistance of drilling tool steel samples. The comparative analysis of microstructure, microhardness and wear-resistance of the samples in initial state and after electrolyte-plasma treatment is represented. It was found out that 18CrNi3MoA-Sh steel microstructure has fine-grained martensite-bainite structure after the treatment. It was determined that 18CrNi3MoA-Sh steel possesses high wear-resistance after electrolyte-plasma treatment, so that technology is characterized by low power consumption and cost price. The initial state microhardness is 2800 MPa on the average. Microhardness on the bearing lane surface after electrolyte-plasma processing is 7500 MPa on the average. Microhardness increases in 2-2.5 times more before treatment that indicates the technology efficiency.

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Kurc-Lisiecka, A., and A. Lisiecki. "Laser welding of stainless steel." Journal of Achievements in Materials and Manufacturing Engineering 1, no. 98 (January 1, 2020): 32–40. http://dx.doi.org/10.5604/01.3001.0014.0815.

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Purpose: of this paper was to analyze the influence of the basic parameters of laser welding (i.e. laser beam power and welding speed, as well as energy input) of butt joints of the 2.0 mm thick stainless steel AISI 304 sheets on the weld shape and joint quality. Design/methodology/approach: The preliminary trials of simulated laser welding by melting the austenitic stainless steel sheets (the so called bead-on-plate welding), as well as the welding of the test butt joints, were carried out using the high-power diode laser (HPDL) ROFIN DL 020, without the additional material (the technique of autogenous welding). A crucial parameter that determines both the mechanical properties and the corrosive resistance of a joint (the region of a weld and HAZ - heat affected zone) in the case of stainless steels with austenitic structure is energy input, which should be kept at a minimum, and at the same time full penetration and a proper shape of the fusion zone should be ensured. The investigations included the macrostructure and microstructure observations by light microscopy, researches of mechanical properties in a static tensile test and also microhardness measurements made by Vickers method. Findings: The results have shown that it is possible to provide a proper shape of the weld of fine-grained structure and narrow heat affected zone, but it requires careful selection of the welding parameters, especially a low energy input. The microhardness measurements showed that the in case of welding the butt joints using the high-power diode laser in HAZ area a slight increase in microhardness to approx. 185HV0.2 compared to base material (160-169HV0.2) and a decrease in microhardness in the fusion zone (FZ) to approx. 140- 150HV0.2 have been observed. All welded sample broke from the joint during the testing at tensile stress between 585 MPa and 605 MPa with corresponding percentage elongation in the range of 45-57%. It can be found that the joints strength is not less than the strength of the base metal of 2.0 mm thick AISI 304 austenitic stainless steel sheet. Research limitations/implications: Studies of the weldability of stainless steels indicate that the basic influence on the quality of welded joints and reduction of thermal distortions has the heat input of welding, moreover the highest quality of welded joints of austenitic stainless steel sheets are ensured only by laser welding. Practical implications: The laser welding technology can be directly applied for welding of austenitic steel AISI 304 sheets 2.0 mm thick. Originality/value: Application of high power diode laser for welding of austenitic stainless steel AISI 304.

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Khyzhnyak, V. G., A. I. Dudka, I. I. Bilyk, O. V. Khyzhnyak, and M. V. Arshuk. "Protective Coatings on Steel Tytanoalitovani 40X13." Фізика і хімія твердого тіла 16, no. 3 (September 15, 2015): 593–98. http://dx.doi.org/10.15330/pcss.16.3.593-598.

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Past studies on application to the surface of steel 40X13 multi tytanoalitovanyh coatings in containers of consumable shutter using a mixture of powders of titanium, aluminum; titanium hydride; tytanoalituvannya steel 40X13 with pre-deposited TiN layer; tytanoalituvannya pre-nitrided steel among ammonia. The possibility of forming coatings on steel 40X13 involving compounds Ti4Fe2O, FeTiAl, TiN, TiC and transition zone. Established distribution of chemical elements and microhardness thickness diffusion coatings. The maximum microhardness detected for layers Tees - 31,0-34,0 GPa; TiN layers for - 19,5-22,5 GPa; for the zone Ti4Fe2O, FeTiAl - 5,0-7,0 GPa.

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Li, Xin, Jie Zhao, Jun Cheng Bao, Bao Qun Ning, and Jian Ping Li. "Microstructure Transformation of Nb-V Microalloyed Steel during Continuous Cooling Process." Advanced Materials Research 590 (November 2012): 23–27. http://dx.doi.org/10.4028/www.scientific.net/amr.590.23.

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To achieve reasonable rolling technology of the novel Nb-V composite microalloyed steel, the continuous cooling transformation (CCT) curve was established by thermal simulation experiment. Microstructure and microhardness at different cooling rates were characterized using an optical microscope (OM) and microhardness tester. The results indicate that the critical quenching speed of Nb-V microalloyed steel is about 23 °C/s. The start and finishing temperatures of phase transformation decreased with the rise of cooling rate. Widmannstatten (W) structure appears at lower cooling rate interval. Microstructure transfers into martensite (M) and bainite (B) with obviously refined grains in higher cooling rate interval. Microhardness improves with the increase of cooling rates. Microhardness value is greatly improved to 298.6 HV at the cooling rate of 11 °C/s, which could be related to the formation of lower bainite during phase transformation process. When the cooling rate is above 29 °C/s, microhardness values remain unchanged basically. This illustrates that the microstructure of Nb-V microalloyed steel consists of martensite and lower bainite.

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Mohamad Basir, Muhamad Hafizuddin, Bulan Abdullah, Mohd Faizul Idham, and Muhammad Hussain Ismail. "Effect of Shot Blasting on Paste Boronizing of 316L Stainless Steel." Key Engineering Materials 740 (June 2017): 25–30. http://dx.doi.org/10.4028/www.scientific.net/kem.740.25.

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This investigation was conducted to study on the effect of shot blasting on the case depth of boride layers produced and microhardness after performing paste boronizing on 316L stainless steel. 250 micron diameter of glass beads had been used in the process of shot blasting with variation in the blasting pressure. Paste boronizing was performed at 850°C with 8 hours of soaking time. The samples involved were tested and analyzed on the microstructure and microhardness. Boride layers of FeB and Fe2B formed due to paste boronizing improve the microhardness of 316L stainless steel and the effect of shot blasting with increasing the blasting pressure increase both of case depth of boride layers and microhardness on the studied metal.

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Bhattacharya, Anirban, Ajay Batish, and Gurpreet Singh. "Surface Modification of High Carbon High Chromium, EN31 and Hot Die Steel Using Powder Mixed EDM Process." Materials Science Forum 701 (October 2011): 43–59. http://dx.doi.org/10.4028/www.scientific.net/msf.701.43.

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This paper investigates the effect of electric discharge machining (EDM) process parameters and powder mixed in dielectric on surface properties of three die steel work materials; namely High Carbon High Chromium (HCHCr), EN 31 and Hot Die Steel (HDS). The mechanism of material deposition from the suspended powder and/or tool electrode is reported. Current emerged as the most significant factor affecting the microhardness along with powder mixed in the dielectric and electrode material. Amongst the two electrode materials, copper-tungsten along with tungsten powder had the best microhardness. Selected samples were analyzed for X-ray Diffraction (XRD) followed by microstructure analysis using a Scanning Electron Microscope (SEM). The results showed significant material transfer from the electrode as well as powder either in free form or in compound form. It was concluded that surface modification of die steels can be done by incorporating simple modifications in the EDM set-up resulting in higher microhardness and superior wear resistance of the machined surface.

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Skakov, Mazhyn, and Yerzhan Sapatayev. "Microstructure and Microhardness Changes of 40Cr Steel after Treatment in the Electrolytic Plasma." Applied Mechanics and Materials 379 (August 2013): 119–23. http://dx.doi.org/10.4028/www.scientific.net/amm.379.119.

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In this work the microstructure and microhardness distribution of modified layers 40Cr (AISI 5140) alloy steel after nitriding by electrolytic plasma have been under research. It is shown that as a result of electrolytic plasma nitriding it becomes possible to increase the surface microhardness of the steel.

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Skakov, Mazhin, Bauyrzhan Rakhadilov, and Michael Sheffler. "Influence of Electrolyte Plasma Treatment on Structure, Phase Composition and Microhardness of Steel Р6М5." Key Engineering Materials 531-532 (December 2012): 627–31. http://dx.doi.org/10.4028/www.scientific.net/kem.531-532.627.

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Microhardness of nitrated and carbonitriding in electrolyte plasma steel Р6М5 surface layers are investigated in the research. It shows perspectiveness of the cutting tool electrolyte-plasma treatment technology. Operating conditions for the technology realization are defined. It was also indicated the desired content of components in saturating mixtures by nitriding and carbonitriding. Comparative research of structure, phase composition of fast-cutting P6M5 steel modified surface layers after electrolyte plasma treatment was carried out by scanning-electron and light microscopy, and X-ray structure analysis methods. The way of electrolytic plasma nitriding in cathodic mode, to provide fast-cutting steels which allows for modification the surface and high kinetic efficiency the process diffusion saturation. It was established that as a result of nitriding and nitrocarburizing in plasma electrolyte has been a significant increase in microhardness in the surface layers of steel Р6M5.

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Volkov, O., S. Knyazev, V. Subbotina, C. Iancu, Yu Gutsalenko, O. Shelkovyi, and R. Strelchuk. "Construction of surface layers with special properties in the hardening of steels." IOP Conference Series: Materials Science and Engineering 1235, no. 1 (March 1, 2022): 012031. http://dx.doi.org/10.1088/1757-899x/1235/1/012031.

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Abstract Designing surface layers with special properties at strengthening of steels gives the chance to receive effective tools of a special purpose. The technological process of hardening by boron saturation of the jewellery tool - crimpings for fixing jewellery stones from carbon steel (0.7% C) is offered. Boron saturation of steel crimpings for fixing jewellery stones was performed before traditional hardening and low tempering. The microhardness of the surface layer of boron saturated steel has been more than doubled: at a depth of up to 50 μm – up to more than 16 GPa against 6 GPa for traditional hardening technology. Between the upper hardened layer and the unaltered inner metal, a transitional structure zone with tempering martensite is observed. This zone has a thickness of about 100 μm and an average microhardness in the range from 10 GPa to about 14 GPa.

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Skakov, Mazhyn, Erlan Batyrbekov, Laila Zhurerova, and Michael Scheffler. "Microstructure and Microhardness Changes of 30CrMnSiA Steel Modified Surface Layers by Electrolyte-Plasma Processing." Applied Mechanics and Materials 423-426 (September 2013): 824–27. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.824.

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This work is devoted to research of 30CrMnSiA steel structurally modified surface layers and study of electrolyte-plasma treatment parameters influence on changing peculiarities of structural-phase state and also the increase of constructional 30CrMnSi steel operating ability. The chosen technology leads to the formation of stable ferrite-pearlite structures in 30CrMnSi steel surface layers, provides high mechanical properties. As for the basic experimental methods of research in the work we used metallographic analysis applying optical microscope «NEOPHOT-21» and «AXIOPHOT-2», Х-ray analysis on the diffractometer ХPertPRO in monochromatic CuKα-radiation, mechanical tests for microhardness on PMT-3М installation. It is established that microstructure of 30CrMnSi steel modified layers samples while different processing modes, consists of α - phase, iron carbides. Using technology of structural steels electrolytic-plasma cementation under arc discharge terms in the electrolyte, we get diffusive surface layer with increased microhardness parameters and wear resistance providing good operating ability for details often subjected to wear.

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Yurov, V. M., E. N. Eremin, and S. A. Guchenko. "Microhardness and wear resistance of a high-entropy coating FeCrNiTiZrAl." Journal of Physics: Conference Series 2182, no. 1 (March 1, 2022): 012083. http://dx.doi.org/10.1088/1742-6596/2182/1/012083.

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Abstract In this article, the microhardness and wear resistance of the high-entropy FeCrNiTiZrAl alloy are studied on model specimens and on turbine blades made of 20Kh13 steel. The alloy was made by mechanical alloying and subsequent annealing in a vacuum furnace. The study showed that the obtained alloy is a high-entropy alloy with a microhardness μ = 740 HV, which is at the level of the microhardness of metallic glasses, but 2-3 times higher than the microhardness of stainless steels. The friction coefficient of the FeCrNiTiZrAl coating is k = 0.06, which is 10 times less than the friction coefficient of the titanium nitride coating (k = 0.65). The wear resistance of the high-entropy FeCrNiTiZrAl coating is much higher than that of stainless steels, and it leads to the fact that the cost of titanium nitride coating on turbine blades is 2 times higher than the cost of FeCrNiTiZrAl coating, that is, the economic effect is obvious.

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Jindal, Sandeep, Rahul Chhibber, and N. P. Mehta. "Effect of Flux Constituents and Basicity Index on Mechanical Properties and Microstructural Evolution of Submerged Arc Welded High Strength Low Alloy Steel." Materials Science Forum 738-739 (January 2013): 242–46. http://dx.doi.org/10.4028/www.scientific.net/msf.738-739.242.

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The application of high strength low alloy (HSLA) steels has been limited by unavailability of suitable joining and filler metals in submerged arc welding (SAW) processes. The present work aims at the design and development of flux for Submerged Arc Welding of HSLA steel. In the work L8 array of Taguchi Design is used to formulate eight types of fluxes to vary basicity index (BI) from 1.26 to 2.81 and to study the effect of flux constituents and basicity index on tensile strength, microhardness and microstructure of the weld metal. Empirical models for ultimate tensile strength and microhardness at the centre of weld versus flux constituents and basicity index have been developed. From the experiments it is found that ultimate tensile strength increase with increase of basicity index with minimum at 1.26 increases upto 2.33 and then further decreases whereas opposite in case of microhardness which is highest at 1.26 and minimum at 1.9. Increase of CaO in the flux increases ultimate tensile strength but microhardness remains unaffected whereas increase of SiO2 decreases ultimate tensile strength but microhardness remains constant. Microhardness decreases critically with increase of CaF2.

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عزيمة, خليل. "تأثير سرعة المسح للحزمة الليزرية على خصائص منطقة التقسية في الفولاذ الكربوني." FES Journal of Engineering Sciences 2, no. 1 (November 6, 2006): 13. http://dx.doi.org/10.52981/fjes.v2i1.85.

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Surface heat treatment of steel by using laser technology is the most developed method of hardening for machine elements and tools, where it formes on the surface structure with optimal properties. The structure depends on phase's transformation which occures in steel after laser treatment. The mechanism of mutual reaction between laser beam and steel is bind by kind of laser generation, wave length, power and scanning speed. The scanning speed of CW laser beam became the most important parameters of laser surface treatment. This paper concentrate on the study of the effect of laser scanning speed for steel surface on the depth of heating zone in three kind of carbon steel and the microhardness inside heat effected zone. It has been shown that both of microhardness and depth of hardening layer are decreased when scanning speed is increased. Also, it has been studied the relation between microhardness and the containment of carbon in steel.

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Miraoui, Imed, Mouna Zaied, and Mohamed Boujelbene. "Effect of Laser Beam Diameter on Cut Edge of Steel Plates Obtained by Laser Machining." Applied Mechanics and Materials 467 (December 2013): 227–32. http://dx.doi.org/10.4028/www.scientific.net/amm.467.227.

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Laser cutting is a thermal process which is used contactless to separate materials. In the present study, high-power laser cutting of steel plates is considered and the thermal influence of laser cutting on the cut edges is examined. The microstructure and the microhardness of the cut edge are affected by the input laser cutting parameter: laser beam diameter. The aim of this work is to investigate the effect of the laser beam diameter on the microhardness beneath the cut surface of steel plates obtained by CO2 laser cutting. The cut surface was studied based on microhardness depth profiles beneath the machined surface. The results show that laser cutting has a thermal effect on the surface microstructure and on the microhardness beneath the cut section. Also the microhardness of the hardening zone depends on the laser beam diameter.

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Moon, Abhijeet, and R. Balasubramaniam. "Determination of Hydrogen Diffusivity in Rail Steels by Sub-Scale Microhardness Profiling Technique." Defect and Diffusion Forum 293 (August 2009): 41–45. http://dx.doi.org/10.4028/www.scientific.net/ddf.293.41.

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Hydrogen diffusivity was estimated in three different eutectoid rail steels (C-Mn, Cu-Mo and Ni-Cu-Cr) at ambient temperatures using the technique of sub-surface microhardness profiling after cathodic hydrogen charging in 0.5mol/l sulphuric acid at a current density of 0.1A/cm2 for 24 hours. The increase in the concentration of hydrogen at a certain depth below the surface was related to the microhardness increase at this location as compared to the bulk value. The procedure used to obtain the diffusion coefficient of hydrogen from the microhardness profiles is discussed. The hydrogen diffusivity values in all of the rail steels were found to be similar (of the order of 10-13m2/sec). The estimated hydrogen diffusivity in the rail steel was lower than in pure iron (10-8m2/sec). Possible reasons for the difference are discussed.

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Singh, Praveen, Satnam Singh, and Sanchit Mewar. "Processing and characterization of high strength dual-phase steel by two-step intercritical heat treatment process." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 233, no. 3 (May 22, 2018): 581–88. http://dx.doi.org/10.1177/0954408918778645.

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A simple approach of two-step intercritical heat treatment has been employed to study the effect of heat treatment on the evolution of microstructures and their effect on the mechanical properties of alloy steel (AISI 1012). The selected steel samples were directly placed in the preheated furnace and were progressively heat treated in two steps, intercritically between the Ac1–Ac3 temperature range. Immediate water quenching (preheated at 30 ℃) was carried out after heat treatment cycles. The processed steels were characterized by examining the X-ray diffraction patterns, microstructures, Vickers microhardness, and tensile strength. The normalized X-ray diffraction results of heat-treated steels revealed the substantial growth in the martenistic phases. The microstructures of heat-treated steel revealed the formation of needle-shape-like structures, which corresponds to the martenistic phase. The increased formation of martenistic phase due to the intercritical heat treatment process improved the overall microhardness (from 188 ± 9 HV of the parent steel to 412 ± 32 HV for 800 ℃ heat-treated steel) up to 2.2 times. The presence of soft and ductile (ferritic and pearlite) phases simultaneously with tough and strong (martenistic) phase allowed the improvement in the ultimate tensile strength. In comparison to parent steel with tensile strength of 510 ± 15 MPa, the intercritical heat treatment steel at 800 ℃ revealed 169.6% higher tensile strength of 1375 ± 35 MPa. However, percentage elongation was reduced by 60%, i.e. from 13 ± 1% for parent steel to 5.2 ± 2% of intercritical heat treatment steel (processed at 800 ℃). An overall study revealed that by a proper intercritical heat treatment process, dual-phase steels with better structure–properties correlation can be obtained for industrial applications.

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Tsvetkova, E. V., K. O. Bazaleeva, I. S. Chekin, O. G. Klimova-Korsmik, and A. S. Zhidkov. "Nitriding of steels of various structural classes manufactured by laser additive technologies." Izvestiya. Ferrous Metallurgy 63, no. 1 (March 30, 2020): 63–70. http://dx.doi.org/10.17073/0368-0797-2020-1-63-70.

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The authors have conducted a comparative analysis of diffusion layers of steels of various structural classes manufactured by complex technology including laser remelting of powder material and plasma nitriding. Parameters of diffusion layers of bainitic steel (Fe – 0.09 % C – 1 % Cr – 2 % Ni – 1 % Mo – 1 % Cu) and martensitic steel (Fe – 0.25 % C – 13 % Cr – 2 % Ni) manufactured by direct laser deposition (DLD) and austenitic steel (Fe – 0.03 % C – 17 % Cr – – 14 % Ni – 3 % Mo) manufactured by selective laser melting (SLM) were investigated. During plasma nitriding at 540 °C for 24 h of martensitic and austenitic steels, diffusion layer of 140 – 160 μm was formed, additionally maximum microhardness of surface layer was 800 HV0.1 and 1050 HV0.1 and it is almost constant on thickness of 100 μm. Diffusing layer of bainitic steel is 900 μm and its microhardness monotonously decreases from the surface. Reinforcing phases of nitrided layer were determined by X-ray analysis: γ′ (Fe4N) is fixed in the bainitic steel, γ′ and CrN are fixed in martensitic and austenitic steels. Moreover on the surface of austenitic steel solid nitrided layer is formed. The influence of heat treatment after laser remelting of powder material was also studied. It was determined, that despite decreasing of crystal structure defects after heat treatment, the thickness of nitrided layer changes slightly. Also the authors have investigated the influence of porosity of austenitic steel on the thickness of nitrided layer. It was shown, that porosity of 0.5 – 2.0 % doesn’t result in changing of diffusion layer’s thickness.

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Guo, Guo Lin, and Yang Li. "The Investigation on Wear Resistance of Fe-Based Alloy Coating by Argon Arc Cladding." Applied Mechanics and Materials 217-219 (November 2012): 1247–50. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.1247.

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By argon arc cladding technology, a Fe-based alloy coating was prepared on the surface of Q235 steel. The microstructure of the cladding coating was investigated by optical microscope (OM) and scanning electron microscope(SEM). The microhardness and wear resistance performance of the coating were tested by microhardness tester and friction-wear tester. The results show that the alloy coating with martensite, alloy solid solution and (Cr, Fe) 7C3/Fe3C/ Fe2B compounds is prepared on the surface of Q235 steel, the microhardness of the coating reaches as high as 600 HV and the wear resistance of the coating is about 8 times higher than that of Q235 steel substrate. When deposited a wear-resistant layer on the surface of mild steel , the high plasticity and ductility are preserved as well as the hardness and wear resistance of the cladding layer are improved greatly.

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Zhang, C. H., Y. F. Jia, M. Guan, C. L. Wu, J. Z. Tan, and S. Zhang. "Microstructure and Property of Fe-Based Alloy Modified Layer on 304 Stainless Steel by High-Energy Pulse Laser-Like Cladding (HPLC)." Materials Science Forum 879 (November 2016): 2255–60. http://dx.doi.org/10.4028/www.scientific.net/msf.879.2255.

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Fe-based alloy modified layers were prepared on 304 stainless steels by high-energy pulse laser-like cold welding cladding technique. The microstructure, composition and phase constituents of the cladding layers were analyzed using SEM, EDS and XRD, respectively. The microhardness, friction-wear and cavitation erosion resistance were also investigated using microhardness tester, pin-on-disk wear-testing machine and ultrasonic vibrator. Experimental results showed that Fe-based alloy modified layer was mainly composed of α-Fe matrix phase and skeleton-like Cr23C6, Cr7C3 carbide reinforced phase, which was dispersively distributed into α-Fe matrix. The microhardness and friction coefficients of Fe-based alloy modified layer were 600HV and 0.4, respectively, indicating an improved wear resistance. The weight loss rate and average erosion depth of the modified layer was 1/5 and 1/10 that of 304 stainless steel in 3.5% NaCl solution after 5-h cavitation erosion test, respectively. The erosion crater depth of the modified layer was uniform, indicating that the cavitation erosion resistance of the modified layer was much better than that of the 304 stainless steel.

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Villanueva-Perez, O. E., I. Mejía, V. García-García, and A. Bedolla-Jacuinde. "Metallographic, Structural and Mechanical Characterization of a Low Density Fe-Mn-Al-C Steel Microalloyed with Ti/B in As-Cast and Homogenized Conditions." MRS Advances 3, no. 64 (2018): 3971–78. http://dx.doi.org/10.1557/adv.2019.64.

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ABSTRACTLow density (LD) steels have shown particular characteristics in terms of mechanical properties and microstructure, since they have high strength, high ductility and density reduction up to 18%. On the other hand, the addition of microalloying elements such as Ti and B generate hardening by solid solution and precipitation, as well as grain refinement effect. LD steels generate nano-sized kappa phase precipitated from the austenite matrix, and these advanced steels can reach strength and elongation up to 780 MPa and 60%, respectively. The main objective of this research work is the metallographic, structural and mechanical characterization of a LD steel microalloyed with Ti/B in as-cast and -homogenized conditions. For this purpose a Fe-27Mn-7Al-1.2C (%wt) LD steel microalloyed with Ti/B was melted in a vacuum-induction furnace and cast in metallic mold. LD-Ti/B steel samples were homogenized at 1100 °C during 20, 50, 100, 150 and 200 minutes followed by water quenching. Metallographic, structural and mechanical characterization was carried out by optical (LOM) and scanning electron (SEM) microscopy, X-ray diffraction (XRD) and microhardness Vickers testing (HV10), respectively. In general, results showed a typical dendritic microstructure with average grain size of 1256 μm in the as-cast condition. On the other hand, the as-homogenized condition showed an austenitic equiaxial microstructure with average grain size from 164 to 940 μm. Austenite, ferrite and kappa phases were detected by X-ray diffraction (XRD). Also, second-phase particles such as AlN, TiC and MnS were detected by LOM and SEM-EDS analysis. LD steel microalloyed with Ti/B exhibited the highest microhardness Vickers value (235 HV10) in the as-cast condition, whilst in the as-homogenized condition microhardness gradually decreases from 223 to 198 HV10 as holding time increases.

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Hao, Jian Jun, Lu Ping Ma, Liang Gao, Yue Jin Ma, and Jian Guo Zhao. "TiCN Cermet Composite Coating Prepared By Reaction Nitrogen Arc Welding Cladding Process." Applied Mechanics and Materials 190-191 (July 2012): 581–84. http://dx.doi.org/10.4028/www.scientific.net/amm.190-191.581.

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A TiCN cermet composite coating was fabricated on 45# steel substrate by reaction nitrogen arc welding cladding technique. The mixture powder of titanium and graphite was preplaced onto the 45# steel substrate after intensive mixing by star ball-mill and gluing with starch binder. The microstructures and phase of the coatings, interracial behavior between coatings and the substrate were investigated by scanning electronic microscope, X-ray diffractometer. The microhardness distribution of the coating section, frictional coefficient, abrasion loss and wearing surface morphology were investigated by microhardness tester, abrasion machine and scanning electronic microscope. The results show that an excellent bonding between the coatings and the 45# steel substrate is ensured by the strong metallurgical interface and phase of the coatings are mainly composed of TiCN. The highest microhardness of the coatings reaches HV 0.5 810, which is about 3 times more than that of the 45# steel substrate. The anti-abrasive test results show the coating has better anti-abrasive performance than the 45# steel substrate.

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Liang, Yan, Yaohui Liu, Yulai Song, and Wei Cui. "Optimizing the Mechanical Properties in the Repair Zone of 5Cr5MoV by Controlling Welding Heat Input." Metals 8, no. 12 (November 23, 2018): 981. http://dx.doi.org/10.3390/met8120981.

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The influence of welding heat input on the microstructure and mechanical properties of 5Cr5MoV die steel was studied in order to improve the mechanical properties of the cold working die and extend its service life. Shielded metal arc welding (SMAW) method was used with different heat inputs in the range from 4.2 to 6.61 kJ/cm to repair the 5Cr5MoV die steel. Microhardness and tensile properties were performed to evaluate the repaired quality of the cold working die steel. The microhardness of the weld repaired zone gradually decreased from the weld to the tempering zone. The highest microhardness in the weld repaired zone was 863 HV, and finally, it decreased to about 300 HV. With the increase of heat input, the tensile strength of the weld and the heat affected zone increased; nevertheless, the tensile strength of the tempering zone increased first and then decreased. As a result, 6.6 kJ/cm is the best value of heat input judged from the microhardness distribution and the tensile properties.

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31

Lajis, Mohd Amri, A. K. M. Nurul Amin, and A. N. Mustafizul Karim. "Surface Integrity in Hot Machining of AISI D2 Hardened Steel." Advanced Materials Research 500 (April 2012): 44–50. http://dx.doi.org/10.4028/www.scientific.net/amr.500.44.

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This study presents experimental results of machined surface integrity of die material (AISI D2 hardened steel) when hot machining (induction heating) assisted end milling using coated carbide is applied. The aim of this work was to study the influence of induction heating temperature, cutting speed, and feed on the effects induced by hard milling on surface integrity (microhardness and work-hardening). Microhardness was measured to observe the distribution of the hardness beneath the surface and to determine the effect of induction heating on the micro-hardness distribution and work-hardening phenomena. The behaviour of microhardness induced in the subsurface region when end milling under room and induction heating cutting conditions using coated carbide inserts was also investigated. The surface integrity and subsurface alteration have been investigated by employing scanning electron microscope (SEM) and Vickers microhardness tester.

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32

Krawczynska, Agnieszka T., Małgorzata Lewandowska, and Krzysztof Jan Kurzydlowski. "Nanostructure Formation in Austenitic Stainless Steel." Solid State Phenomena 140 (October 2008): 173–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.140.173.

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Samples of 316LVM stainless steels were hydrostatically extruded in a multi-step process to a total true strain of 1,84 and subsequently annealed at different temperatures. The structural changes occurring as a result of HE and annealing were observed using a transmission electron microscope. The microhardness of the samples was measured using a load of 200g. The results show that hydrostatic extrusion results in a uniform microstructure characterized by a high density of nano-twins. Subsequent annealing at 600°C produces a partial transformation to a nano structure of average grain size 54 nm. At an annealing temperature of 700°C a fullyrecrystallized uniform microstructure consisting of 68 nm diameter nano-grains was formed. It should be noted that 700°C is much lower than that required to recrystallize a micro-grained alloy of the same composition. The microstructural changes which occurred during annealing have a significant effect on the mechanical properties. The microhardness after HE increased following annealing at 500°C. However, annealing at 800°C resulted in a drop in microhardness, indicating the occurrence of grain growth.

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33

Sohaj, Pavel, and Vít Jan. "Local Changes of Microhardness in Dissimilar Weld Joints after High Temperature Exposure." Key Engineering Materials 586 (September 2013): 249–52. http://dx.doi.org/10.4028/www.scientific.net/kem.586.249.

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The paper presents results obtained during evaluation of dissimilar weld joints of creep-resistant steels. During high temperature exposure of dissimilar weld joints, alloying elements were redistributed across the weld interface. These diffusion effects can cause local changes of microstructure and have a direct effect on local mechanical properties in weld interface area. Carbon and nitrogen have the strongest influence on changes of mechanical properties of steels. . These local changes of mechanical properties have a strong influence on the reliability and the service live of the whole welded structures. The dissimilar joints of the austenitic steel/martenzitic steel type was studied. Laboratory weld joints were prepared and annealed at different temperatures for different time periods. Microhardness profiles across the weld interface were measured and the influence of long-term, high temperature exposure on the changes of local microhardness was evaluated. Results were compared with pseudo-binary phase diagrams and with the literature.

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Tęcza, G., and A. Garbacz-Klempka. "Microstructure of Cast High-Manganese Steel Containing Titanium." Archives of Foundry Engineering 16, no. 4 (December 1, 2016): 163–68. http://dx.doi.org/10.1515/afe-2016-0103.

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Abstract Widely used in the power and mining industry, cast Hadfield steel is resistant to wear, but only when operating under impact loads. Components made from this alloy exposed to the effect of abrasion under load-free conditions are known to suffer rapid and premature wear. To increase the abrasion resistance of cast high-manganese steel under the conditions where no dynamic loads are operating, primary titanium carbides are formed in the process of cast steel melting, to obtain in the alloy after solidification and heat treatment, the microstructure composed of very hard primary carbides uniformly distributed in the austenitic matrix of a hardness superior to the hardness of common cast Hadfield steel. Hard titanium carbides ultimately improve the wear resistance of components operating under shear conditions. The measured microhardness of the as-cast matrix in samples tested was observed to increase with the increasing content of titanium and was 380 HV0.02 for the content of 0.4%, 410 HV0.02 for the content of 1.5% and 510 HV0.02 for the content of 2 and 2.5%. After solution heat treatment, the microhardness of the matrix was 460÷480 HV0.02 for melts T2, T3 and T6, and 580 HV0.02 for melt T4, and was higher than the values obtained in common cast Hadfield steel (370 HV0.02 in as-cast state and 340÷370 HV0.02 after solution heat treatment). The measured microhardness of alloyed cementite was 1030÷1270 HV0.02; the microhardness of carbides reached even 2650÷4000 HV0.02.

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35

Xia, M., N. Sreenivasan, S. Lawson, Y. Zhou, and Z. Tian. "A Comparative Study of Formability of Diode Laser Welds in DP980 and HSLA Steels." Journal of Engineering Materials and Technology 129, no. 3 (January 4, 2007): 446–52. http://dx.doi.org/10.1115/1.2744417.

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Understanding effects of welding on strength and formability is critical to support wider application of advanced high strength steels in automotive components. In this study, High Strength Low Alloy (HSLA) and DP980 (Dual Phase, 980MPa) sheet steels were welded with a 4kW diode laser. Mechanical properties of welds and parent metals were assessed by tensile and limiting dome height tests, and related to microhardness distribution across the welds. The formability of HSLA welds was insensitive to the welding process and comparable to that of parent metal. For the DP steel, weld formability was much lower than that of corresponding parent metal, which appeared to be due to the formation of soft zones in the outer region of the Heat affected zone (HAZ) of the welds. It was found that increase of welding speed resulted in a slight increase of formability of the DP steel, associated with a reduction in the microhardness difference between base metal and HAZ soft zones.

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36

Sowa, M., W. Szyszko, J. Sielanko, L. Glusiec, and B. Kamieńska. "Microhardness of Boron, Titanium, and Nitrogen Implanted Steel." Physica Status Solidi (a) 112, no. 2 (April 16, 1989): 839–43. http://dx.doi.org/10.1002/pssa.2211120255.

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37

Riabkina-Fishman, M., and J. Zahavi. "Structure and microhardness of laser-hardened 1045 steel." Journal of Materials Science 23, no. 5 (May 1988): 1547–52. http://dx.doi.org/10.1007/bf01115689.

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38

Shi, Hong Xin, Zhi Wei Wu, Jing Sun, Hua Yu, Ran Feng Qiu, and Ke Ke Zhang. "Study on the Joint of Isothermal Superplastic Solid State Welding between Cr12MoV Steel and 40Cr Steel after Laser Surface Quenching." Advanced Materials Research 154-155 (October 2010): 817–21. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.817.

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The 40Cr steel surface waiting for being welded was ultra-fined through laser quenching, and isothermal superplastic solid state welding was conducted between the 40Cr steel and Cr12MoV steel. The mechanical properties of the joint were evaluated by tensile testing and microhardness of the joint and thereby. The microstructure of 40Cr steel’s quenching layer and the joint interface zone was observed and analyzed using scan electron microscope. The experimental results show that ultra-fine microstructure is achieved in the 40Cr steel’s surface waiting for being welded. The superplastic solid state welding can be carried out under welding parameters including welding temperature of 800 , pressure welding time of 4 min and initial strain rate of 1.5×10-4 S-1. The tensile strength of joint achieves 81.94% that of 40Cr steel. The microhardness of transition region in the Cr12MoV side is higher than other region. On the contrary, the microhardness in the 40Cr side is lower than other region. The new M7C3 type carbide is checked in the Cr12MoV side. In welding process, the carbon atom has diffused from 40Cr steel side to Cr12MoV steel side. Therefore, isothermal superplastic solid state welding with higher quality can be realized between Cr12MoV steel and the 40Cr steel after microstructure ultra-fining through laser quenching.

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Fatyukhin, Dmitriy S., Ravil I. Nigmetzyanov, Sergey K. Sundukov, and Aleksandr V. Sukhov. "Stages of Cavitation Erosion Development on Steel Surfaces." Key Engineering Materials 910 (February 15, 2022): 773–78. http://dx.doi.org/10.4028/p-56f3i2.

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The authors investigated the effect of ultrasonic cavitation on the surface of St3, 20, 45 steels. It was found that cavitation causes a change in the structure and properties of the surface layer of the samples. A refinement of the grain and an increase in the microhardness of the surface layer similar for the investigated materials were revealed. The dependences of dynamics of the increase in microhardness under the action of ultrasound were given, which show that there was a steady state, characterized by an indicator of relative microhardness of 1.3...1.5. The results of changes in the parameters of roughness and sub-roughness were given. Studies showed that cavitation erosion leads to an increase in altitude and step parameters of the surface microgeometry. The research results can be used for development and creation of ultrasonic technological processes carried out in liquid media.

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Tulinski, Maciej, and Mieczyslaw Jurczyk. "Mechanical and Corrosion Properties of Ni-Free Austenitic Stainless Steel/Hydroxyapatite Nanocomposites." Solid State Phenomena 151 (April 2009): 213–16. http://dx.doi.org/10.4028/www.scientific.net/ssp.151.213.

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In the present work, a nanocrystalline nickel-free stainless steels as well as nickel-free stainless steel/hydroxyapatite nanocomposites have been synthesized by the combination of mechanical alloying (MA), heat treatment and nitriding. The microhardness of the final bulk material was studied using Vickers method. Corrosion potentiodynamic tests were performed in Ringer’s solution. The results show that nickel-free stainless steel/hydroxyapatite nanocomposites could be promising bionanomaterials for use as a hard tissue replacement implants.

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Mishigdorzhiyn, Undrakh, Aleksandr Semenov, Nikolay Ulakhanov, Aleksandr Milonov, Dorzho Dasheev, and Pavel Gulyashinov. "Microstructure and Wear Resistance of Hot-Work Tool Steels after Electron Beam Surface Alloying with B4C and Al." Lubricants 10, no. 5 (May 7, 2022): 90. http://dx.doi.org/10.3390/lubricants10050090.

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(1) Background: Operational properties and durability of dies in different metal-forming processes significantly depend on their surface quality. Major die failures are related to surface damage due to heat checking cracks, wear, etc. Thereby, strengthening of the working surfaces of dies for hot bending, stamping, forging, and die casting processes is an urgent engineering challenge. Surface alloying with high-energy beams improves the properties of steel products. In these processes, the alloying powders and the treated surfaces can be remelted by electron beam within a short time while the bulk structure of the component remains unchanged, resulting in minimal distortion. The paper presents the results of the electron beam surface alloying (EBSA) of H21 and L6 tool steels with the treatment pastes containing boron carbide and aluminum powders. (2) Methods: Two types of pastes were used for surface alloying: a single-component (B4C) paste and a two-component (B4C+Al) one. The microstructure, microhardness, wear resistance, and elemental and phase composition of the layers obtained on steels were investigated. (3) Results: Four layers up to 0.4 mm thick were distinguished on the surface of the steels after the EBSA. Metallographic analysis showed coarse dendrite formation in the layers embedded in matrices of a eutectic or a solid solution. Microhardness of the steels after the two-component EBSA was higher than after B4C EBSA, which was related to a higher concentration of hard phases, such as iron borides and carbides. In addition, aluminum boride was revealed by the XRD analysis on L6 steel after B4C+Al EBSA. (4) Conclusions: Wear test indicated that the most resistant samples were H21 steel after single B4C EBSA and L6 steel after B4C+Al EBSA. Both samples contained carbon particles in the layer contributing to the high wear resistance as a lubricant. The conducted research is beneficial for mechanical engineering, automotive engineering, medical technology, aerospace engineering, and related industries, where coatings with high microhardness, wear resistance, and surface quality are demanded.

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42

Skakov, Mazhyn, Laila Zhurerova, and Michael Scheffler. "Way of Hardening Surface Coating of Details from Steel 30CrMnSi in Electrolytic Plasma." Key Engineering Materials 531-532 (December 2012): 178–81. http://dx.doi.org/10.4028/www.scientific.net/kem.531-532.178.

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The present work is devoted research of influence of various modes of electrolytic-plasma cementation on feature of change a structurally-phase conditions and hardening of a constructional steel 30CrMnSi. It is chosen scientifically proved low-power and resources-economy a processing kind which leads to formation stable ferrite-perlites structures, provides higher mechanical properties. Cementation process carried out with selection of different modes of electrolytic-plasma processing in the electrolyte containing water solution of 10 % of sodium carbonate and 10 % of glycerin. As the basic methods of research in work we used metallographic the analysis with microscope application «NEOPHOT-21», X-ray analysis on diffractometer Х’PertPRO in monochromatic CrKα - radiation, tests for microhardness for device PMT-3. It is established that a microstructure of samples steel 30CrMnSi at different modes of processing consist from α - phases, particle carbides. Microhardness of the initial sample makes approximately 3000 МPа, and after processing its microhardness makes 6100 МPа that speaks about of a processing mode. The developed technology of electrolytic-plasma cementation of constructional steels in the conditions of the arc category in electrolyte is the optimal as provides reliable quality and demanded properties of details, working in variable loadings and often exposed to wear, forms the strengthened, modified surface coating.

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Skakov, Маzhyn, Sherzod Kurbanbekov, Michail Scheffler, and Azretay Naltaev. "Modification of Stainless Steels Surface Layers by Nitriding and Carbonitriding." Advanced Materials Research 712-715 (June 2013): 12–16. http://dx.doi.org/10.4028/www.scientific.net/amr.712-715.12.

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The structure of low-carbon steels after saturation by nitrogen and carbon in the mode of electrolytic-plasma nitriding and carbonitriding on the surface structure of austenitic stainless steel 12Cr18Ni10Ti has been studied. Optimum modes of electrolytic-plasma nitriding and carbonitriding are determined ensuring the maximum saturation of nitrogen and carbon, the microhardness of the surface. It is established, that after electrolyte-plasma processing microstructure of steel 12Cr18Ni10Ti has martensite structure. As a result of the research it is revealed that steel 12Cr18Ni10Ti after the electrolyte-plasma processing has high hardness.

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Skakov, Маzhyn, Sherzod Kurbanbekov, Yerkezhan Tabieva, and Erkin Zamanbekuly. "Nitriding and Carbonitriding Influence on Stainless Steels Surface Layers Changes." Applied Mechanics and Materials 379 (August 2013): 105–9. http://dx.doi.org/10.4028/www.scientific.net/amm.379.105.

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The structure of low-carbon steels after saturation by nitrogen and carbon in the mode of electrolytic-plasma nitriding and carbonitriding on the surface structure of austenitic stainless steel 12Cr18Ni10Ti has been studied. Optimum modes of electrolytic-plasma nitriding and carbonitriding are determined ensuring the maximum saturation of nitrogen and carbon, the microhardness of the surface. It is established, that after electrolyte-plasma processing microstructure of steel 12Cr18Ni10Ti has martensite structure. As a result of the research it is revealed that steel 12Cr18Ni10Ti after the electrolyte-plasma processing has high hardness.

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Mihaliková, Mária, Kristína Zgodavová, Peter Bober, and Anna Špegárová. "The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates." Materials 14, no. 6 (March 22, 2021): 1553. http://dx.doi.org/10.3390/ma14061553.

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The presented research background is a car body manufacturer’s request to test the car body’s components welded from dissimilar steel sheets. In view of the vehicle crew’s protection, it is necessary to study the static and dynamic behavior of welded steels. Therefore, the influence of laser welding on the mechanical and dynamical properties, microstructure, microhardness, and welded joint surface roughness of interstitial free CR180IF and dual-phase DP600 steels were investigated. Static tensile tests were carried out by using testing machine Zwick 1387, and dynamic test used rotary hammer machine RSO. Sheet steel was tested at different strain rates ranging from 10−3 to 103 s−1. The laser welds’ microstructure and microhardness were evaluated in the base metal, heat-affected zone, and fusion zone. The comprehensive analysis also included chemical analysis, fracture surface analysis, and roughness measurement. The research results showed that the strain rate had an influence on the mechanical properties of base materials and welded joints. The dynamic loading increases the yield stress more than the ultimate tensile strength for the monitored steels, while the most significant increase was recorded for the welded material.

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Kukareko, Vladimir, Vasile Agafii, Valentin Mihailov, Aleksandr Grigorchic, and Natalia Kazak. "Evaluation of Tribological Properties of Hard Coatings Obtained on Steel C45 by Electro-Spark Alloying." Key Engineering Materials 813 (July 2019): 381–86. http://dx.doi.org/10.4028/www.scientific.net/kem.813.381.

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It was shown that under dry contact conditions, under normal load of to 2 MPa, all coatings demonstrated a significant increase in wear resistance compared to that of the substrate. However, among them, the Mo coating showed the highest wear resistance: ~20 times higher than that of the uncoated steel. That was caused not only by the Mo high microhardness and the lowest initial roughness, but also by the structure of this coating. Meanwhile, the Ti + SiC samples displayed the highest microhardness among investigated coatings. A correlation was established between the microhardness of the coating and the friction coefficient: the larger the microhardness of the coating, the higher is the coefficient of friction. An X-ray analysis of the coatings obtained by ESA on steel with compositions (Ti + Al + C), (Ti + AlN) and (Ti + SiC) revealed phases of titanium carbide, titanium nitride, intermetallic compound AlFe3, and small amounts of aluminum nitride, silicon dioxide and titanium dioxide. This could explain the high microhardness (from 6.8 up to 13.8 GPa) of the obtained coatings.

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Alrabii, S. A., and L. Y. Zumot. "Chip Thickness and Microhardness Prediction Models during Turning of Medium Carbon Steel." Journal of Applied Mathematics 2007 (2007): 1–12. http://dx.doi.org/10.1155/2007/51905.

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Cutting tests were conducted to medium carbon steel using HSS tools with cutting fluid. The experimental design used was based on response surface methodology (RSM) using a central composite design. Chips were collected at different machining conditions and thickness and microhardness measurements taken and analyzed using “DESIGN EXPERT 7” experimental design software. Mathematical models of the responses (thickness and microhardness) as functions of the conditions (speed, feed, and depth of cut) were obtained and studied. The resultant second-order models show chip thickness increases when increasing feed and speed, while increasing depth of cut resulted in a little effect on chip thickness. Chip microhardness increases with increasing depth of cut. It also increases with increasing speed and feed up to a certain level beyond which further increases cause a drop in microhardness.

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Dogan, Halit, Fehim Findik, and Ahmet Oztarhan. "Tribological studies of ZrO2‐implanted on stainless steel substrate." Industrial Lubrication and Tribology 56, no. 6 (December 1, 2004): 341–45. http://dx.doi.org/10.1108/00368790410558257.

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The tribological properties such as surface hardness, friction and wear have been studied for AISI 316L stainless steel substrates which were co‐ion implanted with zirconium and oxygen ions. It is found that the wear resistance for AISI 316L stainless steel substrates implanted with zirconium and oxygen ions increased quite a lot. It is concluded that the increase in surface microhardness and the decrease in friction coefficient of AISI 316L stainless steel substrates play an important role in improving the wear resistance, and the relationship between relative wear volume and microhardness is correlated for zirconium and oxygen co‐ion implantation.

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Duan, Chun Zheng, Min Jie Wang, and Tao Dou. "Microscopic Examination of Primary Shear Zone in High Speed Machining of Hardened High Strength Steel." Advanced Materials Research 97-101 (March 2010): 1887–90. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.1887.

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The microstructure observation and microhardness measurement were performed on the adiabatic shear bands in primary shear zone in the serrated chips formed during high speed machining of two tempering hardness of hardened high strength steel under different cutting speeds by optical microscope, SEM, TEM and microhardness tester. The investigation results show that two types of adiabatic shear bands are formed as cutting speed increases. One is deformed band with heavy elongated microstructures generated under lower cutting speed, another is transformed band with fine grains under higher cutting speed. The increase of the cutting speed little influences on the microhardness in the transformed bands, and the microhardness in deformed band results from strain hardening, whereas transformation hardening leads to very high microhardness in transformed band.

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50

Łapiński, Z., A. Dziedzic, W. Bochnowski, S. Adamiak, and S. Sandomierski. "The Quality of Welded Connections Elements from the Steel 30HGS and Titanium Alloy Ti6Al4V." Archives of Foundry Engineering 12, no. 2 (April 1, 2012): 159–66. http://dx.doi.org/10.2478/v10266-012-0056-3.

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The Quality of Welded Connections Elements from the Steel 30HGS and Titanium Alloy Ti6Al4V The aim of that work was the evaluation of the quality of welded connections elements (welds) from the 30HGS steel and titanium alloy Ti6Al4V. The metallographic, factographic tests were used, and measurements of microhardness with the Vickers method. In the head weld of the 30HGS steel there were non-metallic partial division and bubbles observed. The average microhardness in the head connection was 320 HV0.1. There was no significant increase/decrease observed of microhardness in the head influence zone of the weld. There was a good condition of head connections observed, in accordance with the standard EN12517 and EN25817. In the head weld of Ti6Al4V titanium alloy there were single, occasional non-metallic interjections and bubbles observed. There were no cracks both on the weld, and on the border of the heat influence zone. The value of microhardness in head connection was in the range 300÷445 HV0.1. Reveal a very good condition of the head connections in accordance with the standard EN12517 and EN25817. The factographic tests prove the correctness of welded connections done and then heat treatment in case of steel and titanium alloy.

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Journal articles on the topic 'Microhardness of steel'

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