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1
Ruddy, John. "Conservation compendium. Part 3: Historic wrought iron, cast iron and mild steel". Structural Engineer 93, n. 2 (1 febbraio 2015): 44–46. http://dx.doi.org/10.56330/nhsa9029.
Testo completoAbstract (sommario):
As structural engineering students, we learn about mild steel, modern design and construction methods. However, historic structures often do not fit into this mould. Whether you work in conservation or are a general practitioner, you are likely to come across cast iron, wrought iron, as well as early mild steel structures.
2
Pechlivani, E. M., e F. Stergioudis. "Commensurability of the Structures of Boride Layers". Key Engineering Materials 495 (novembre 2011): 181–84. http://dx.doi.org/10.4028/www.scientific.net/kem.495.181.
Testo completoAbstract (sommario):
The interaction of solid NH4HCO3 with iron, where the ammonia product has been adsorbed nondissociatively to iron surfaces at low temperatures [1] was investigated. The nitride clusters formed on steel substrates modified the surface morphology and characteristics of the substrate and influenced their adhesion during subsequent procedure of coating. In our case, efforts were made to decorate the steel substrate in order to influence the base metal reactivity towards boron and its ability to react and form stable compounds with boron [2]. Boride layers on steel are examined by means of SEM and XRD analysis. The decorated surface was observed by FTIR method.
3
Kuo, Chin-Guo, Lih-Ren Hwang e Yen-Tien Kang. "A study of microstructure and tensile property with casting S45C welding". MATEC Web of Conferences 185 (2018): 00032. http://dx.doi.org/10.1051/matecconf/201818500032.
Testo completoAbstract (sommario):
For energy saving and longer life time of a large casting iron may use of weld repairs or make up to more save manufacture time and energy than re-casting. Such as breakage, crack and wear in large casting iron castings used weld to repair casting for eco-energy. The purpose of this study is to investigate the dissimilar joint property of S45C carbon steel with the multi-layer method and the multi-pass welding method. Four weld rods, experimentally examined the influence on microstructures, which were marked as A, B, C and D, respectively. The microstructures of joint bead were observed by the optical microscope. The specimens of tensile test were made according to ASTM E8M. The experimental results were shown as following: 1. The pearlite structures and the bainite structures were formed in welded zone by the weld rod of middle carbon steels. The yield strength and ultimate strength of the specimens were 360MPa and 460MPa. 2. The feature of welded specimen was close to stainless steel due to the stainless steel rod included some Cr and Ni. In addition, a ferritic-austenitic two-phase stainless steel was observed in optical microscope.
4
Crosby-Jones, F. "CORROSION OF IRON AND STEEL STRUCTURES AND THEIR PRESERVATION". Journal of the American Society for Naval Engineers 26, n. 2 (18 marzo 2009): 602–4. http://dx.doi.org/10.1111/j.1559-3584.1914.tb01142.x.
Testo completo
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Maraveas, Chrysanthos, Zacharias Fasoulakis e Konstantinos Daniel Tsavdaridis. "Post-fire assessment and reinstatement of steel structures". Journal of Structural Fire Engineering 8, n. 2 (12 giugno 2017): 181–201. http://dx.doi.org/10.1108/jsfe-03-2017-0028.
Testo completoAbstract (sommario):
Purpose This paper aims to present technical aspects of the assessment method and evaluation of fire damaged steel structures. The current work focuses on the behavior of structural normal steel (hot-rolled and cold-formed) and high-strength bolts after exposure to elevated temperatures. Information on stainless steel, cast iron and wrought iron is also presented. Design/methodology/approach Because of the complexity of the issue, an elaborate presentation of the mechanical properties influencing factors is followed. Subsequently, a wide range of experimental studies is extensively reviewed in the literature while simplified equations for determining the post-fire mechanical properties are proposed, following appropriate categorization. Moreover, the reinstatement survey is also comprehensively described. Findings Useful conclusions are drawn for the safe reuse of the structural elements and connection components. According to the parametric investigation of the aforementioned data, it can be safely concluded that the most common scenario of buildings after fire events, i.e. apart from excessively distorted structures, implies considerable remaining capacity of the structure, highlighting that subsequent demolition should not be the case, especially regarding critical infrastructure and buildings. Originality/value The stability of the structure as a whole is addressed, with aim to establish specific guidelines and code provisions for the correct appraisal and rehabilitation of fire damaged structures.
6
Emelianov, Vitalii, Sergei Chernyi, Anton Zinchenko, Nataliia Emelianova, Elena Zinchenko e Kirill Chernobai. "Information System for Diagnosing the Condition of the Complex Structures Based on Neural Networks". Energies 15, n. 9 (19 aprile 2022): 2977. http://dx.doi.org/10.3390/en15092977.
Testo completoAbstract (sommario):
In this paper, we describe the relevance of diagnosing the lining condition of steel ladles in metallurgical facilities. Accidents with steel ladles lead to losses and different types of damage in iron and steel works. We developed an algorithm for recognizing thermograms of steel ladles to identify burnout zones in the lining based on the technology and design of neural networks. A diagnostic system structure for automated evaluating of the technical conditions of steel ladles without taking them out of service has been developed and described.
7
Ning, Jiang Li, Lu Huang e Ya Tong Zhang. "The Strength-Ductility Balance of an Ultrafine-Grained Medium-Carbon Steel Produced by Severe Plastic Deformation". Key Engineering Materials 727 (gennaio 2017): 211–17. http://dx.doi.org/10.4028/www.scientific.net/kem.727.211.
Testo completoAbstract (sommario):
By processing with different high pressure torsion procedures, we obtained ultrafine-grained structures in medium-carbon steel and pure iron with different microstructural features. The UFG carbon steel exhibited a better balance of tensile strength and ductility in comparison with the UFG pure iron. The higher strength of the carbon steel is ascribed to the finer ferrite grain size, the dispersed carbide particles and the presence of alloying elements. The reasonable ductility of carbon steel is attributed to the maintaining of positive work hardening rate at high strain stage of tension, owing to the presence of intragranular particles and high fraction of high-angle boundaries.
8
Pusterhofer, Michael, Florian Summer, Michael Maier e Florian Grün. "Assessment of Shaft Surface Structures on the Tribological Behavior of Journal Bearings by Physical and Virtual Simulation". Lubricants 8, n. 1 (15 gennaio 2020): 8. http://dx.doi.org/10.3390/lubricants8010008.
Testo completoAbstract (sommario):
Optimizing the surface topography of cast iron crankshafts offers the opportunity to use this material as an alternative to steel in high-performance combustion engines. In the past, this was not possible due to the higher wear on bearing shells and the higher friction losses in relation to forged steel shafts. In order to find an optimized shaft micro topography, the friction and wear behavior of steel and cast iron shafts with different surface treatments were compared to each other, using a combined physical (experimental) and a virtual (computational) simulation approach. The experiments were carried out with a rotary tribometer using a journal bearing test configuration with the possibility to test real-life bearing shells and shaft specimens, manufactured from real-life crankshafts. In the experiments, a polished steel shaft with low bearing wear was effective. The optimization of cast iron crankshafts by a novel surface treatment showed a significant reduction of bearing wear in relation to the classical surface finishing procedures of cast iron shafts. A computational simulation approach, considering the real-life micro topography by using the Navier–Stokes equations for the calculation of micro hydrodynamics, supports the assessment of fluid friction. The virtual simulation shows, in accordance to the experimental results, only a minor influence of the investigated shaft topographies on the fluid friction. Further optimization of shaft surfaces for journal bearing systems seems possible only by the usage of patterned micro topographies.
9
Berdiev, D. M., M. A. Umarova, B. M. Saydumarov e T. N. Ibodullaev. "Establishing the influence of structure parameters of steel on their abrasive wear resistance". E3S Web of Conferences 371 (2023): 01016. http://dx.doi.org/10.1051/e3sconf/202337101016.
Testo completoAbstract (sommario):
We studied carbon steels (from technical iron to Y8) and low-alloy steel 65G. The grades of these steels are regulated by GOST 8559-75. To create different structures in the studied steels, the samples were subjected to heat treatment. The processing modes were selected in such a way as to ensure the study of the effect on wear resistance of one structural parameter of steel with the relative stability of other parameters. The relationships between the parameters of the structure of heat-treated steels and their abrasive wear resistance are established. At all temperatures of the final tempering of hardened steel, there is a direct relationship between its structure parameters (the number of elements in a solid solution, the density of dislocations, the size of cementite particles and the intercementite distance) and wear resistance when sliding friction against loose abrasive particles. A computer program has been developed to select the chemical composition of the steel grade and methods of thermal hardening in order to ensure the required wear resistance.
10
Bao, Wei Ping, Zhi Ping Xiong, Fu Ming Wang, Jian Shu e Xue Ping Ren. "Comparison of Dynamic Mechanical Properties between Pure Iron (BCC) and Fe-30Mn-3Si-4Al TWIP Steel (FCC)". Applied Mechanics and Materials 692 (novembre 2014): 179–86. http://dx.doi.org/10.4028/www.scientific.net/amm.692.179.
Testo completoAbstract (sommario):
Dynamic mechanical properties and microstructures of pure iron and Fe-30Mn-3Si-4Al TWIP (TWinning Induced Plasticity) steel were conducted by SHPB (Split-Hopkinson Pressure Bar), OM (Optical Microscopy) and TEM (Transmission Electron Microscope), at the strain rate ranging from 102 to 105 s-1 and at room temperature. The effect of high strain rate on the mechanical responses of pure iron and Fe-30Mn-3Si-4Al TWIP steel belonging to BCC (Body Centered Cubic) and FCC (Face Centered Cubic) structures respectively was evaluated. The comparison of deformation mechanism was analyzed between them and it concluded that dislocation gliding is a major deformation mechanism in pure iron with BCC structure and deformation twinning plays a significant role in Fe-30Mn-3Si-4Al TWIP steel with FCC structure.
11
Wang, Sizhe, Maryam Mohri, Lingzhen Li, Mohammadreza Izadi, Ali Jafarabadi, Niels Pichler e Elyas Ghafoori. "Memory‐Steel for Smart Steel Structures: A Review on Recent Developments and Applications". ce/papers 6, n. 3-4 (settembre 2023): 949–58. http://dx.doi.org/10.1002/cepa.2756.
Testo completoAbstract (sommario):
AbstractThis study reviews the recent works on the development and application of iron‐based shape memory alloy (Fe‐SMA), the so‐called memory‐steel, for steel structures. First, the studies on the material properties of Fe‐SMA in terms of shape memory effect and superelasticity are discussed. Next, the use of Fe‐SMA in prestressed strengthening of steel structures is explained, including the applications in strengthening of steel girders, connections, and fatigue crack repairs. Various strengthening solutions such as using mechanically anchored or adhesively‐bonded Fe‐SMA, as well as the studies on the behavior of the Fe‐SMA‐to‐steel bonded joints, are discussed. The use and application of Fe‐SMA for strengthening of a 113‐years steel bridge has been explained. In addition, studies on the innovative application of the Fe‐SMA as pipe couplers are presented. At the end, innovative ongoing research on the additive manufacturing of architected Fe‐SMA (4D‐printing) are discussed.
12
Sachidananda, Khwairakpam. "Comparisons of Performance of Building Using Bright New And Old Rusted Rebar". Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, n. 1 (19 dicembre 2022): 295–99. http://dx.doi.org/10.38208/acp.v1.511.
Testo completoAbstract (sommario):
Reinforced cement concrete structure are the most common structures in India. The strength of structure depends mainly on two components i.e. concrete and steel rebar. One of the main constituent i.e. steel, changes its strength along with the changes in property of steel rebar irrespective of the types of steel, mainly due to rusting of iron i.e. formation of iron oxide by the reaction of iron and oxygen in the presence of water or air moisture. In the present study, experimental investigation has been done as to find the property of steel for the bright new rebar as well as for the old rusted rebar of a particular brand of steel rebar. The experimental result showed that the new bright rebar has ~ 50% higher yielding strength as compared to the old rusted rebar strength. The ductility of new bright rebar is having ~125% higher than the old rusted rebar. The material property of steel extracted from the experiment has been incorporated in Finite Element modelling of a particular building using SAP 2000. The building has been designed under the gravity load as well as uniform lateral load. The performance of building is found out through push over analysis in terms of load vs displacement. The ultimate strength of building using new rebar is around 60% higher than the strength of building with old rebar. The displacement capacity of building also differs significantly i.e. building with new rebar is having ~60% higher than building with old rebar’s. Overall, the steel rebars need to be protected from corrosion for the construction of structures.
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Chinnuraj, Shanmugam, PR Thyla, S. Elango, Prabhu Raja Venugopal, PV Mohanram, Mahendrakumar Nataraj, S. Mohanraj, KN Manojkumar e Siddarth Ayyasamy. "Static and dynamic behavior of steel-reinforced epoxy granite CNC lathe bed using finite element analysis". Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 234, n. 4 (10 febbraio 2020): 595–609. http://dx.doi.org/10.1177/1464420720904606.
Testo completoAbstract (sommario):
Machine tools are used to manufacture components with desired size, shape, and surface finish. The accuracy of machining is influenced by stiffness, structural damping, and long-term dimensional stability of the machine tool structures. Components machined using such machines exhibit more dimensional variations because of the excessive vibration during machining at higher speeds. Compared to conventional materials like cast iron, stone-based polymer composites such as epoxy granite have been found to provide improved damping characteristics, by seven to ten folds, due to which they are being considered for machine tool structures as alternate materials. The stiffness of structures made of epoxy granite can be enhanced by reinforcing with structural steel. The current work highlights the design and analysis of different steel reinforcements in the lathe bed made of the epoxy granite composite to achieve equivalent stiffness to that of cast iron bed for improved static and dynamic performances of the CNC lathe. A finite element model of the existing the cast iron bed was developed to evaluate the static (torsional rigidity) and dynamic characteristics (natural frequency) and the results were validated using the experimental results. Then finite element models of five different steel reinforcement designs of the epoxy granite bed were developed, and their static and dynamic behaviors were compared with the cast iron bed through numerical simulation using finite element analysis. The proposed design (Design-5) of the epoxy granite bed is found to have an improvement in dynamic characteristics by 4–10% with improved stiffness and offers a mass reduction of 22% compared to the cast iron bed, hence it can be used for the manufacture of the CNC lathe bed and other machine tool structures for enhanced performance.
14
Berdiev Sherzod, Berdiev Sherzod. "ADJUSTABLE NITROOXIDATION TECHNOLOGY FOR LOW ALLOY STEEL". European Journal of Artificial Intelligence and Digital Economy 1, n. 3 (10 maggio 2024): 7–11. http://dx.doi.org/10.61796/jaide.v1i3.364.
Testo completoAbstract (sommario):
The article discusses the production of a surface diffusion nitride-oxide layer on low-alloy structural steel with specified structures and properties. To develop a controlled technology for nitro-oxidation of low-alloy carbon steel, the dependences of the composition and structure of the nitrided and oxide layer on the chemical composition of the steel and the technological parameters of the process were studied. Technical iron was used as a model alloy and samples of industrial steel grades 40X, P6M5 and steel 45 were processed. Saturation temperatures were studied in the ranges above and below the eutectoid temperature for the “Fe-N” system and, accordingly, for the “Fe-O” system and it was found that the best structures are at saturation temperatures below the eutectoid
15
Alimardonovich, Berdiev Sherzod. "ADJUSTABLE NITROOXIDATION TECHNOLOGY FOR LOW ALLOY STEEL". European Journal of Artificial Intelligence and Digital Economy 1, n. 2 (14 marzo 2024): 62–66. http://dx.doi.org/10.61796/jaide.v1i2.365.
Testo completoAbstract (sommario):
The article discusses the production of a surface diffusion nitride-oxide layer on low-alloy structural steel with specified structures and properties. To develop a controlled technology for nitro-oxidation of low-alloy carbon steel, the dependences of the composition and structure of the nitrided and oxide layer on the chemical composition of the steel and the technological parameters of the process were studied. Technical iron was used as a model alloy and samples of industrial steel grades 40X, P6M5 and steel 45 were processed. Saturation temperatures were studied in the ranges above and below the eutectoid temperature for the “Fe-N” system and, accordingly, for the “Fe-O” system and it was found that the best structures are at saturation temperatures below the eutectoid
16
Berdiev Sherzod Alimardonovich. "ADJUSTABLE NITROOXIDATION TECHNOLOGY FOR LOW ALLOY STEEL". European Journal of Artificial Intelligence and Digital Economy 1, n. 2 (15 febbraio 2024): 57–61. http://dx.doi.org/10.61796/jaide.v1i2.287.
Testo completoAbstract (sommario):
The article discusses the production of a surface diffusion nitride-oxide layer on low-alloy structural steel with specified structures and properties. To develop a controlled technology for nitro-oxidation of low-alloy carbon steel, the dependences of the composition and structure of the nitrided and oxide layer on the chemical composition of the steel and the technological parameters of the process were studied. Technical iron was used as a model alloy and samples of industrial steel grades 40X, P6M5 and steel 45 were processed. Saturation temperatures were studied in the ranges above and below the eutectoid temperature for the “Fe-N” system and, accordingly, for the “Fe-O” system and it was found that the best structures are at saturation temperatures below the eutectoid.
17
Li, Yun Feng. "Sustainable Manufacturing Technology and Properties of Steel Slag Concrete". Advanced Materials Research 97-101 (marzo 2010): 901–4. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.901.
Testo completoAbstract (sommario):
Early-age deterioration of concrete due to cracking and higher maintenance cost for poor durability cause serious troubles to concrete structures. Steel slag is a solid waste discharged in large quantities by the iron and steel industry. Steel slag includes a certain scale mineral such as C2S and C3S, and can be applied in cement and concrete as mineral admixtures. When mineral admixtures with steel slag powder and blast-furnace slag powder are mixed into concrete, the performance of concrete can be improved further. Mineral admixtures with steel slag powder as partial replacement for Portland cement in mortar is an effective means for enhancing abrasion resistance. Steel slag powder can be used to reduce cracking in concrete at early age, so that it will improve the durability of concrete structures.
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Müller, Max, Dorothea Czempas, David Bailly e Gerhard Hirt. "Twin Roll Casting and Secondary Cooling of 6.0 wt.% Silicon Steel". Metals 11, n. 10 (23 settembre 2021): 1508. http://dx.doi.org/10.3390/met11101508.
Testo completoAbstract (sommario):
Iron–silicon alloys with up to 6.5 wt.% Si offer an improvement of soft magnetic properties in electrical steels compared to conventional electrical steel grades. However, steels with high Si contents are very brittle and cannot be produced by cold rolling. In addition to solid solution hardening, it is assumed that the B2- and DO3-superlattice structures are responsible for the poor cold workability. In this work, two cast strips with 6.0 wt.% Si were successfully produced by the twin roll strip casting process and cooled differently by secondary cooling. The aim of the different cooling strategies was to suppress the formation of the embrittling superlattice structures and thus enable further processing by cold rolling. A comprehensive material characterization allows for the understanding of the influence of casting parameters and cooling strategies on segregation, microstructure and superlattice structure. The results show that both cooling strategies are not sufficient to prevent the formation of B2- and DO3-structures. Although the dark field images show a condition which is far from equilibrium, the achieved condition is not sufficient to ensure cold processing of the material.
19
Chandra-ambhorn, Somrerk, Shigenari Hayashi, Laurence Latu-Romain e Patthranit Wongpromrat. "CHAPTER 4 High Temperature Oxidation of Stainless Steels". Solid State Phenomena 300 (febbraio 2020): 81–106. http://dx.doi.org/10.4028/www.scientific.net/ssp.300.81.
Testo completoAbstract (sommario):
This chapter is dedicated to the description of high temperature oxidation of both chromia and alumina forming alloys. The defect structures of iron and chromium are firstly reviewed. The effects of elements on stainless steel oxidation behaviour are further addressed. For the chromia-forming stainless steel, the oxidation rate is reduced with the increased silicon content but not in a monotonic manner. Titanium and niobium can reduce breakaway oxidation of Fe–18Cr–10Ni austenitic stainless steel. Titanium can enhance the adhesion of scale to the Fe–18Cr by mechanical keying effect of TiO2 formed at the steel/scale interface. For the alumina-forming stainless steel, the formation of alumina and its transformation during oxidation are reviewed. Chromium can be added to reduce the critical aluminium content in the steels in order to form alumina at high temperatures. The addition of reactive elements with appropriate level can improve scale adhesion and reduce the steel oxidation rate. Refractory element like molybdenum can increase strength of material but also accelerate the oxidation rate of the steels containing reactive elements. The development of new alumina-forming austenitic alloy grades is finally described.
20
Belaïd, F., G. Arliguie e R. Francois. "Corrosion Products of Galvanized Rebars Embedded in Chloride-Contaminated Concrete". Corrosion 56, n. 9 (1 settembre 2000): 960–65. http://dx.doi.org/10.5006/1.3280600.
Testo completoAbstract (sommario):
Abstract Iron corrosion products of steel reinforcement result in staining, cracking, and spalling of concrete structures. These effects of corrosion require costly repairs and maintenance during the useful life of the structures. To prevent corrosion of important infrastructure projects, galvanized reinforcing steel occasionally is used. The performance of galvanized steel in chloride-contaminated concrete is attributed to the corrosion product form: zinc oxide (ZnO), which is less voluminous than iron corrosion products. However, zinc corrosion products detected on galvanized reinforcement are rather controversial. Some authors identified another compound: zinc hydroxychloride (Zn5[OH]8Cl2·H2O). This product occupies more space than ZnO and can induce cracking of the cover concrete. Other authors found zinc hydroxychloride and zinc hydroxide (Zn[OH]2). In this work, ZnO and Zn5(OH)8Cl2·H2O were identified. Under some conditions (exposure time in aggressive environment and coating thickness) and after cracking of concrete cover, Zn(OH)2 also was found.
21
UZUNOGLU, Deniz, e Ayla OZER. "Synthesis of Iron-containing Nanoparticles from Iron-Steel Industrial Waste for Adsorption of Malachite Green". Eurasia Proceedings of Science Technology Engineering and Mathematics 17 (16 settembre 2022): 6–18. http://dx.doi.org/10.55549/epstem.1175888.
Testo completoAbstract (sommario):
For the synthesis of iron-containing nanoparticles (FeNPs), the iron ions were recovered from iron-steel industrial waste by leaching method followed by the chemical precipitation of ferric hydroxide with NH3. The ferric hydroxide was reduced pyrometallurgical to iron-containing nanoparticles by the reducing agent of CO generated from charcoal. FeNPs were characterized by XRD and SEM analysis. XRD results showed that FeNPs had predominantly face-centered cubic Fe3O4 structure, besides, the peaks of Fe2O3 and Fe0 structures were also observed. The particle size of FeNPs was calculated as 57.75 nm using Williamson–Hall equation. According to SEM images, FeNPs had homogeneous and spherical-like structures; also, the structures partially decomposed and the particle size increased due to the agglomeration of the particles after adsorption. FeNPs were used as an adsorbent for the removal of Malachite Green (MG). The experimental design and the optimization of experimental conditions were investigated by using response surface methodology (RSM) according to central composite design (CCD). The optimum experimental conditions were determined as 180 min contact time, 75 °C temperature, and 300 mg/L initial MG concentration. The agreement between the adsorbed MG concentrations at the equilibrium (qe) calculated from the model (148.43 mg/g) and determined experimentally (146.63 mg/g) under the optimum conditions showed that the selected model was suitable for MG adsorption by FeNPs. Langmuir isotherm model had higher R2 and lower ARE values than Freundlich isotherm model, showing that the equilibrium data of MG adsorption with FeNPs was the best agreement to Langmuir isotherm model with the maximum monolayer coverage capacity of 175.44 mg dye/g FeNPs. The thermodynamic studies suggested that the adsorption process was endothermic, spontaneous at the optimum conditions, and the positive ΔS value indicated the increased disorder at the solid-solution interface during the adsorption.
22
Gershman, Iosif, Alexander Mironov, German Fox Rabinovich, Tamara Muravyeva, Ivan Shkalei, Olga Shcherbakova, Elena Torskaya, Sergey Fedorov e Jose Luis Endrino. "Secondary Structures on the Friction Surface of Diamond-like Coating". Coatings 12, n. 11 (5 novembre 2022): 1685. http://dx.doi.org/10.3390/coatings12111685.
Testo completoAbstract (sommario):
Peculiarities of the formation of secondary structures on the surface of a diamond-like coating are studied on the example of a friction contact between a steel ball and a diamond-like coating. The friction surface was examined in various areas; the zone of wear products (the boundary of the friction track) and the original surface outside the friction area. It is shown that secondary structures with a high content of iron, nickel, manganese, chromium, and oxygen are characteristic of areas with the highest wear resistance. Such secondary structures are formed because of the intense interaction of the diamond-like coating with the steel of the ball during dry friction.
23
Blumbergs, Ervins, Viktors Mironovs e Genadijs Sahmenko. "COMPARATIVE STUDIES OF THE STRENGTH CHARACTERISTICS OF CONCRETE BLOCKS WITH TITANIUM AND IRON RODS (BARS)". ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 3 (13 giugno 2023): 56–60. http://dx.doi.org/10.17770/etr2023vol3.7303.
Testo completoAbstract (sommario):
The relevance of the topic of the work was shown by the accident of a multi-storey residential building in Miami, which was caused by corrosion of steel reinforcement in reinforced concrete.There is a need to maintain the bearing capacity of structures for a long time in a humid climate, aggressive environmental influences and temperature fluctuations with a lower consumption of materials used.The use of titanium will allow changing some parameters of titanium concrete structures in comparison with reinforced concrete structures. The protective layer of concrete, which serves to protect the reinforcement from the effects of the external environment, will be significantly reduced. This will help to reduce the mass of concrete structures while maintaining strength properties and will allow you to create lighter structures that can withstand heavy loads.Strength tests were carried out on concrete blocks reinforced with smooth iron or titanium rods Ø10 mm, which showed the prospects of replacing steel reinforcement with titanium reinforcement in reinforced concrete.
24
Li, Lingzhen, Sizhe Wang, Eleni Chatzi, Masoud Motavalli e Elyas Ghafoori. "Prediction of prestress level in steel structures strengthened by bonded Fe‐SMA strips". ce/papers 6, n. 3-4 (settembre 2023): 364–68. http://dx.doi.org/10.1002/cepa.2402.
Testo completoAbstract (sommario):
AbstractPrevious studies have demonstrated a great potential of prestressed strengthening of steel structures employing iron‐based shape memory alloys (Fe‐SMAs). A bonded Fe‐SMA strengthening solution has been proposed with partial activation, in which the prestrained Fe‐SMA strip is fully bonded onto the steel structure, and the middle region of the Fe‐SMA strip is heated to generate prestress. The two ends remain unheated and transfer the prestress to the parent structure. In this study, a column model and a beam model are developed to analyze the prestress level in the steel structures strengthened by bonded Fe‐SMA. The predicted strains in the parent structure are in excellent agreement with the experimental measurement from the literature.
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Taub, Alan, Emmanuel De Moor, Alan Luo, David K. Matlock, John G. Speer e Uday Vaidya. "Materials for Automotive Lightweighting". Annual Review of Materials Research 49, n. 1 (luglio 2019): 327–59. http://dx.doi.org/10.1146/annurev-matsci-070218-010134.
Testo completoAbstract (sommario):
Reducing the weight of automobiles is a major contributor to increased fuel economy. The baseline materials for vehicle construction, low-carbon steel and cast iron, are being replaced by materials with higher specific strength and stiffness: advanced high-strength steels, aluminum, magnesium, and polymer composites. The key challenge is to reduce the cost of manufacturing structures with these new materials. Maximizing the weight reduction requires optimized designs utilizing multimaterials in various forms. This use of mixed materials presents additional challenges in joining and preventing galvanic corrosion.
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Skakov, Mazhyn, Erlan Batyrbekov, Laila Zhurerova e Michael Scheffler. "Microstructure and Microhardness Changes of 30CrMnSiA Steel Modified Surface Layers by Electrolyte-Plasma Processing". Applied Mechanics and Materials 423-426 (settembre 2013): 824–27. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.824.
Testo completoAbstract (sommario):
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.
27
Qiu, Tao, e Yonggang Zhang. "Experimental Research on the Adhesion Characteristics of Clay to Structures with Different Materials". Geofluids 2021 (4 agosto 2021): 1–11. http://dx.doi.org/10.1155/2021/3794889.
Testo completoAbstract (sommario):
When the shield machine passes through the clay layer, the clay debris cut by the cutter head usually adheres to the surface of the cutter head and is easy to form mud cakes after extrusion, which affects the safety and efficiency of construction. For the structure made of different materials, due to the different surface properties, the adhesion characteristics of clay are also different. So, selecting proper materials for the soil contacting parts in the shield machine can effectively reduce the adhesion between the structure and soil, decrease the clay adhering to the surface of the shield cutter, and reduce the possibility of further productions of mud cake. Therefore, studying the adhesion properties of clay to different materials and understanding the adhesion rule of clay to soil contacting structures are of guiding significance when selecting the materials of soil contacting parts. In this paper, the adhesion properties of cohesive soil to commonly used construction materials were studied by a self-made adhesion test device, including steel, iron, copper, aluminum, and engineering plastics (polyamide). According to the findings, the separation process of adhesion between soil and the structure by an external force can be divided into four stages, which are the adhesive elastic development stage, adhesive plastic development stage, failure stage, and detachment stage. The adhesion forces and the amount of soil adhered to the structures made of the selected materials are found to vary from each other. The adhesion forces ranked from high to low are, respectively, found on the iron, plastic, aluminum, steel, and copper surfaces. The material with the most amount of adherent soil is aluminum, followed by iron, steel, copper, and plastic.
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Jiang, Zhi Qiang, Xi Lan Feng e Xian Zhang Feng. "A Study on the Structures and Properties of B-Bearing Cast Steel for Wear Resistance". Applied Mechanics and Materials 34-35 (ottobre 2010): 878–82. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.878.
Testo completoAbstract (sommario):
The microstructures of B-bearing cast steel containing 0.8-1.2 wt.%B, 0.8-1.2 wt.%Cr, 1.0-1.5 wt.%Mn, 0.6-1.0 wt.%Si and 0.10-0.25 wt.%C have been characterized by means of optical OM, SEM, EPMA and XRD. The solidification structure of B-steel consists of pearlite, ferrite, martensite and boride (Fe2B), while the hardness is 1430-1480 HV. Borides distribute along the grain boundary in the form of eutectic. Fine lath martensite and eutectic Fe2B can be obtained by water quenching at 1223 K-1273 K. The hardness and impact toughness of the B-steel exceed 55 HRC and 150 kJ/m2, respectively. The abrasion resistance determined using a pin abrasion tester is obviously higher than that of the martensitic cast steel and nears to the high chromium white cast iron.
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Venkata Ramana, Mula, Pudukarai Ramaswamy Thyla, Elango Subramanian e Shanmugam Chinnuraj. "Thermal Investigations on a CNC Lathe Fitted with a Dynamically Enhanced Steel-Reinforced Epoxy Granite Bed". Strojniški vestnik - Journal of Mechanical Engineering 69, n. 3-4 (29 marzo 2023): 169–84. http://dx.doi.org/10.5545/sv-jme.2022.356.
Testo completoAbstract (sommario):
Polymer concrete or epoxy granite is becoming more popular for beds, bases, and other structures of precision machine tools, owing to its excellent damping characteristics. To realize the same static rigidity as that of the cast-iron structures, steel-reinforced epoxy granite (SREG) structures are being used. The vast differences in the thermal properties of steel and epoxy granite (EG) are likely to cause higher magnitudes of thermal error. This work aims to investigate the thermal behaviour of a computerized numerical control (CNC) lathe built with a novel dynamically enhanced SREG bed and compare its performance with the lathe with a cast iron bed. Experimental and numerical investigations have been carried out under cross-feed (CF) drive idle running conditions to determine the TCP deformation. The results reveal that the thermal error in the CNC lathe with SREG bed is 1.68 times that of the lathe with cast iron (CI) bed at 20 ºC and 1.8 times at 40 ºC environmental temperature variation chamber (ETVC) conditions. It could be identified that the heat generated in the CF is conducted to the steel guideways embedded in the SREG bed, but further heat transfer to the EG portion of the bed is impeded, and hence the heat accumulation that occurs in the guideways leads to higher magnitude of the thermal error. The experimentally validated numerical model is used to extend the investigations to study the effect of the idle running of the longitudinal feed drive (LF) and combined cross and longitudinal feed drives, on the thermal behaviour of the lathe.
30
Leslie, Thomas. "Built Like Bridges: Iron, Steel, and Rivets in the Nineteenth-century Skyscraper". Journal of the Society of Architectural Historians 69, n. 2 (1 giugno 2010): 234–61. http://dx.doi.org/10.1525/jsah.2010.69.2.234.
Testo completoAbstract (sommario):
Thomas Leslie explains that the wind-induced collapse of the Tay Bridge in Scotland in 1879 illustrated the vulnerability of tall metal frames to lateral forces. Built Like Bridges: Iron, Steel, and Rivets in the Nineteenth-century Skyscraper recounts the revolution in structural methods that followed, culminating in the mid-1890s with the invention of the riveted all-steel skeleton frame and the elimination of thick masonry shear walls. The first generation of wind-braced skyscraper metal frames relied on bridgelike systems of cross bracing or shiplike systems of knee bracing, but these structures intruded into rentable spaces. The second generation of frames better exploited the material properties of steel, making stiff connections between girders and columns that, when multiplied throughout the building, could collectively resist lateral forces without such intrusions. Steel——which had replaced cast iron as a structural material by 1895——excelled in this role because it could be rolled into efficient, workable shapes and riveted to form tight connections.
31
Wcislik, Wiktor. "Numerical Simulation of Void Nucleation in S355 Steel". Solid State Phenomena 250 (aprile 2016): 244–49. http://dx.doi.org/10.4028/www.scientific.net/ssp.250.244.
Testo completoAbstract (sommario):
The study presents the numerical simulation of the void nucleation process due to decohesion of the interface between the matrix and inclusion of iron carbide Fe3C, under high stress state triaxiality ratio, which is equal to 1.345. The analysis was conducted for S355J2G3 steel, commonly used in civil engineering structures. Special attention was paid to the determination of the value of void nucleation strain.
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Venugopal, Prabhu Raja, P. Dhanabal, PR Thyla, S. Mohanraj, Mahendrakumar Nataraj, M. Ramu e Harshad Sonawane. "Design and analysis of epoxy granite vertical machining centre base for improved static and dynamic characteristics". Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 234, n. 3 (17 dicembre 2019): 481–95. http://dx.doi.org/10.1177/1464420719890892.
Testo completoAbstract (sommario):
The structural vibration in conventional machine tools which are generally made of cast iron may lead to poor surface finish of the machined components. This has led to the investigations on alternative materials for machine tool structures such as concrete, polymer concrete and epoxy granite which have higher damping properties but lesser Young's modulus. However, higher static stiffness with higher damping is essential for improving the static and dynamic characteristics of machine tool structures. Hence, this work focuses on replacing the vertical machining centre base made of cast iron with steel reinforced epoxy granite to improve the structural static stiffness. A finite element model of the above base is developed and validated against the experimental data obtained using modal analysis. The validated numerical approach is applied for investigating the seven progressive design configurations of base reinforced with steel. It is found that the epoxy granite base of Design configuration-7 with L-channels has significantly reduced the deformation by 56 and 36% considering milling and drilling operations, respectively, in comparison to cast iron base. Further, the natural frequencies of the above configuration are higher in all the modes (by more than 50%) under consideration than those of the existing cast iron structure. Therefore, the proposed configuration of base is a viable alternative for the existing base in order to achieve higher structural damping. The novelty of the present work is the design of epoxy granite vertical machining centre base using steel reinforcements to improve structural rigidity with ease of manufacturing.
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Zinyakov, N. M., e O. E. Poshekhonova. "Forged products by Russian craftsmen of the 17th–19th centuries on the basis of materials from the Kikki-Akki burial ground of Upper Taz Selkups: technological characteristics". VESTNIK ARHEOLOGII, ANTROPOLOGII I ETNOGRAFII, n. 1(48) (2 marzo 2020): 65–77. http://dx.doi.org/10.20874/2071-0437-2020-48-1-7.
Testo completoAbstract (sommario):
The article studies the technology of making iron and steel items of Russian origin, discovered in the Kikki-Akki burial ground of Northern Selkups (18th–19th centuries) in the north of Western Siberia in the upper reaches of the Taz River. In the study, we established the origin and chronology of Russian industrial goods in Western Siberia, as well as factors under the influence of which they appeared among the indigenous Siberian population. We examined knives and axes (17th — early 19th centuries) using the methods of metallographic analysis includ-ing macro- and micrographic examination, as well as microhardness testing. They provide an opportunity to de-termine the structure of the metal, which in turn helps determine chemical composition, physical and mechanical properties of the product. The analysis of forged products revealed that they were made according to the techno-logical traditions of Russian metalworking production existing in the 17th — early 19th centuries. Its distinctive features included the development and widespread practice in applying the modifications of two technological schemes for producing items from ferrous metal. The former was based on the welding either of iron and steel or of different grades of steel, whereas the latter involved all-steel structures. The former technological scheme pre-dominated in the production of items found in the Kikki-Akki burial ground. Moreover, the production of welded structures lacked standardisation. The following techniques were used in the production of knives: two-layer wel-ding of iron and steel, three-layer welding, V-joint welding, oblique welding, built-up welding at the ends and wel-ding of the steel blade. The use of soft quenching was noted as an additional operation that improved the opera-tional properties of the household tool. This variety of used technological schemes reflects the complex nature of the formation of the industrial goods market in Western Siberia. The selection of items made using different welded technologies is associated with the intention to use metal products of the highest quality for the fur trade and yasak collection. However, all-metal structures predominated in the main centres for the production of forged goods — cities of European Russia and Western Siberia.
34
Pereira, Álvaro, Manuel Cabaleiro, Borja Conde e Ana Sánchez-Rodríguez. "Automatic Identification and Geometrical Modeling of Steel Rivets of Historical Structures from Lidar Data". Remote Sensing 13, n. 11 (27 maggio 2021): 2108. http://dx.doi.org/10.3390/rs13112108.
Testo completoAbstract (sommario):
Riveting is a joining technique that was widely used in iron and steel structures from the mid-nineteenth to the early twentieth century. Nowadays, many of these riveted structures are still in service around the world, and in many instances, also constitute an important part of the built cultural heritage. The maintenance and conservation of this type of construction is a crucial task for which the HBIM (Historic Building Information Modeling) methodology has recently gained increased attention, postulating itself as the ideal tool for tracking control and conservation-related actions. In the process of data collection and 3D modeling of the structure, the rivets are an important part to be taken into account in the structural safety assessment and health monitoring over time. Any structure of this typology typically presents thousands of rivets, so its measurement and subsequent 3D geometrical modeling is a laborious task and a source of possible errors. Accordingly, this work presents a novel methodology that allows the automatic identification and 3D modeling of rivets in iron and steel structures from Lidar data. The proposed methodology has been tested with both laboratory specimens and a full-scale real bridge.
35
Zhou, Wen Qiang, Li Bo Pan, Kuan Hui Hu, Wei Hua Sun e Rong Dong Han. "Effect of Original Microstructure on Microstructure and Mechanical Properties of High Strength Steel WHF1500H during Hot Forming". Materials Science Forum 941 (dicembre 2018): 206–11. http://dx.doi.org/10.4028/www.scientific.net/msf.941.206.
Testo completoAbstract (sommario):
The press hardening steel sheets WHF1500H with different original structures produced by compact strip production (CSP) line in Wuhan Iron and Steel Ltd. were austenitized at 950 °C for 5 min, and then hot stamped and quenched by using the flat die. The microstructure and mechanical properties were investigated by optical microscope, transmission electron microscope and universal testing machine. The results show that the microstructure after stamping and quenching is fully composed of lath martensite. The mechanical properties of the steel samples with different original structures are different after hot stamping and quenching, and this difference is smaller than that before hot stamping and quenching. When the original structure consists of ferrite and pearlite, the austenite grains after austenitization are fine and uniform. In addition, the martensite structure obtained after hot stamping and quenching is also uniform and fine, leading to higher mechanical properties. With the increase of the strength of the original steel, when the original structure is martensite, the austenite grains after austenitization are coarse, and the martensite structures obtained after quenching is also coarse, and thereby decreasing the strength.
36
Lv, Bo, Chen Chen, Fucheng Zhang, Gennady M. Poletaev e Roman Y. Rakitin. "Potentials for Describing Interatomic Interactions in γFe-Mn-C-N System". Metals 12, n. 6 (7 giugno 2022): 982. http://dx.doi.org/10.3390/met12060982.
Testo completoAbstract (sommario):
Potentials for describing interatomic interactions in a γFe-Mn-C-N multicomponent system, modified Hadfield steel, where face-centered cubic (f.c.c.) iron is the main component, are proposed. To describe the Fe-Fe interactions in austenite, it is proposed to use Lau EAM potential. For all other interactions, Morse potentials are proposed, the parameters of which were found from various experimental characteristics: in particular, the energy of dissolution and migration of an impurity in an f.c.c. iron crystal, the radius of atoms, their electronegativity, mutual binding energy, etc. The found potentials are intended for modeling the atomic structures and processes occurring at the atomic level in Hadfield steel using relatively large computational cells by the molecular dynamics method.
37
Benito, Josep Antonio, Robert Tejedor, Rodriguez Rodríguez-Baracaldo, Jose María Cabrera e Jose Manuel Prado. "Ductility of Bulk Nanocrystalline and Ultrafine Grain Iron and Steel". Materials Science Forum 633-634 (novembre 2009): 197–203. http://dx.doi.org/10.4028/www.scientific.net/msf.633-634.197.
Testo completoAbstract (sommario):
This paper reviews the ductility of nanostructured and ultrafine iron obtained using a variety of methods. Mechanical milling of powder and subsequent hot consolidation, one of the most popular methods offer high mechanical strength but poor ductility. Improvements made in the consolidation processes and the introduction of final heat treatments, in addition to new approaches such as spark plasma sintering and high pressure torsion, have increased the total plastic strain of nanostructured iron. The development of bimodal structures enables the existence of strain hardening and more uniform deformation. The paper also includes a steel study, which finds that the hardness of milled powder and the role of carbon atoms inside ferrite grains make it more difficult to improve the ductility of nanostructured samples.
38
di Lorenzo, Gianmaria, Fabio Rizzo, Antonio Formisano, Raffaele Landolfo e Antonio Guastaferro. "Corrosion Wastage Models for Steel Structures: Literature Review and a New Interpretative Formulation for Wrought Iron Alloys". Key Engineering Materials 813 (luglio 2019): 209–14. http://dx.doi.org/10.4028/www.scientific.net/kem.813.209.
Testo completoAbstract (sommario):
Damage due to atmospheric corrosion on metal structures is a significant aspect for both the design of new constructions and the maintenance of existing buildings. The paper discusses the corrosion depth trends for steel structures comparing an experimental campaign of measurements, given by Fratesi in 2002, with literature 2nd level models calibrated from experiments on immersed elements, literature models based on testing in atmosphere and standard codes (i.e. EN ISO 9224 and EN 12500). Results show a significant variability of values using different models and codes. In addition, the paper underlines that literature studies and codes neglect specific models for nineteenth-century “wrought iron” constructions, that are very sensitive to corrosion phenomena. Based on this, the paper discusses results obtained by a new interpretative model developed by authors for the prediction of corrosion depth on wrought iron structures.
39
Takaki, Tomohiro, Shogo Ito, Kazuhiko Kitamura, Kazuhiro Yagishita e Junichi Shibata. "Relationship between Molecular Structures of Organic-Sulfur Compounds and Metal Forming Performance". Key Engineering Materials 716 (ottobre 2016): 190–98. http://dx.doi.org/10.4028/www.scientific.net/kem.716.190.
Testo completoAbstract (sommario):
Oil with a chlorinated extremely-pressure additive (EP-additive) is effective to prevent galling in cold forming for stainless steel. However environmental issues have pressured the manufacture to replace this oil with high performance oil without chloride. Particularly, sulfur-based EP-additives are accepted as a practicable replacement for chlorinated EP-additives. Thus, the authors analyzed the structures of organic-sulfur compounds. Moreover, the effects of the molecular structures on the anti-galling performance are estimated by a cup internal ironing test. This test has been devised to classify the performance of sample oils by the ironing load and the damage on the workpiece after the test. Consequently, sulfurized olefin was superior to sulfurized ester and sulfurized fatty oil in cold ironing for stainless steel. It was also clarified that sulfur EP-additives generated iron sulfide and sulfate on the surface of stainless steel by using the surface analyses of X-ray photoelectron spectroscopy.
40
Zarghamee, Mehdi S., e Keng-Wit Lim. "Accidental Drop Load Effects on Buried Structures". Journal of Disaster Research 5, n. 6 (1 dicembre 2010): 712–19. http://dx.doi.org/10.20965/jdr.2010.p0712.
Testo completoAbstract (sommario):
The finite-element model we propose to analyze the dynamics of accidental drop loads on critical buried structures during steam generator replacement includes representation of drop objects, impacted structures, soil media through which stress waves travel, and buried structures. Analysis accounts for the nonlinear effects of large deformation, steel plasticity and buckling, concrete cracking and crushing , and stress wave damping through soil. Stress and strain in buried structures is used to evaluate the condition of buried structures such as buried prestressed concrete and ductile iron pipelines and reinforced concrete structures housing critical components subjected to accidental drop loads during steam generator replacement near nuclear reactors operations.
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Saito, Noritaka. "Estimation of rheological characteristics of dual phase fluid at high temperature utilizing transfer learning". Impact 2020, n. 1 (27 febbraio 2020): 82–84. http://dx.doi.org/10.21820/23987073.2020.1.82.
Testo completoAbstract (sommario):
Steel, when first refined and put into widescale use changed construction and engineering. Skyscrapers, mega bridges and other massive structures reinforced with this miracle material changed skylines all over the world and opened the door for vast improvements in infrastructure. Steel is still a major component of building projects today and the steel beam is often considered as one of the impressive feats of human engineering. Steel is what chemists and engineers refer to as an alloy, meaning it is a composite material of several different elements. This alloy is mostly made with iron and carbon but can contain other elements as well. The blending of these elements with iron, the base metal of steel, gives it a high tensile strength at a low cost of production, making it the transformative material we know today. However, this metal is not without drawbacks as the process of refining steel generates several difficult to deal with by-products. Professor Noritaka Saito, who is based in the Department of Materials Science & Engineering, at Kyushu University in Japan, is looking at developing accurate ways to measure the properties of these mixtures so that industry can more efficiently produce precise composite materials.
42
Arkundato, Artoto, Ratna Dewi Syarifah, Mohammad Ali Shafi’i, Fiber Monado e Iwan Sugihartono. "Molecular dynamics simulation of corrosion and its inhibition: comparison of structural stability of Fe/FeNi/FeNiCr/FeNiCrTi steels under high-temperature liquid lead". EUREKA: Physics and Engineering, n. 6 (29 novembre 2022): 151–63. http://dx.doi.org/10.21303/2461-4262.2022.002619.
Testo completoAbstract (sommario):
The liquid lead used in fast nuclear reactor has been known to be able to cause a significant damage to the steels. Therefore, finding new materials with high corrosion resistance is the goal of much research current days. Likewise, developing a way to prevent corrosion is also the goal of designers of nuclear reactors. In the present study, we studied materials: Fe, FeNi, FeNiCr, and FeNiCrTi (a type of SS 316L austenite steel), comparing their structural stability when interacted with molten liquid lead at 750 °C. The performance of each steel is compared under high-temperature molten lead coolant, checking the structure's stability to see the material resistance to corrosion attack of liquid lead. The corrosion can also be seen from the data of iron diffusion coefficient. The larger of the iron diffusion coefficient can be associated with larger corrosion because there is a high solubility of iron atoms from the steel surface to the molten lead. The popular way to prevent more corrosion is by injecting oxygen into the lead coolant. This current work uses the molecular dynamics method to simulate the corrosion and inhibition phenomena. The research aims to compare the performance of Fe, FeNi, FeNiCr, and FeNiCrTi under liquid lead at a temperature of 750. The diffusion coefficient of iron of material will be calculated to describe quantitatively the corrosion level of those structural materials and the corrosion inhibition by oxygen injection. The study has produced important results that adding Ni, Cr, Ti into a pure iron crystal to build alloy steel will make the material stronger, structurally compact, and more resistant to corrosion. For specific composition of steels, from weaker to stronger that resist from corrosion attack, it is possible to make ordering: Fe<<FeNi<FeNiCr<FeNiCrTi. The composition of FeNiCrTi steel in this work is Fe(75)Ni(10.57)Cr(14.05)Ti(0.40). The high corrosion of FeNiCrTi in the liquid lead is effectively reduced by injecting 0.0112 wt % oxygen into lead coolant as a limit value for maximum corrosion inhibition
43
Adachi, Shoya, Minoru Hayashi, Taisei Kawakami, Yuto Ando, Jin Wang, Kenji Sakai, Toshihiko Kiwa, Toshiyuki Ishikawa e Keiji Tsukada. "Thickness Measurement at High Lift-Off for Underwater Corroded Iron-Steel Structures Using a Magnetic Sensor Probe". Sensors 23, n. 1 (29 dicembre 2022): 380. http://dx.doi.org/10.3390/s23010380.
Testo completoAbstract (sommario):
Infrastructure facilities that were built approximately half a century ago have rapidly aged. Steel sheet piles, the inspection object in this study, are severely corroded, resulting in cave-in damages at wharfs. To solve such a problem, non-destructive inspection techniques are required. We previously demonstrated plate thickness measurement using extremely low-frequency eddy current testing. However, when the steel sheet piles are located in water, shellfish adhere to their surface, causing a lift-off of several tens of millimeters. Therefore, this large lift-off hinders the thickness measurement owing to fluctuations of magnetic signals. In this study, sensor probes with different coil diameters were prototyped and the optimum size for measuring steel sheet piles at high lift-off was investigated. Using the probes, the magnetic field was applied with a lift-off range from 0 to 80 mm, and the intensity and phase of the detected magnetic field were analyzed. Subsequently, by increasing the probe diameter, a good sensitivity was obtained for the thickness estimation with a lift-off of up to 60 mm. Moreover, these probes were used to measure the thickness of actual steel sheet piles, and measurements were successfully obtained at a high lift-off.
44
Elhoud, Abdu. "Immersion Corrosion Tests to Evaluate Polyaspartic Coatings on Steel". Hungarian Journal of Industry and Chemistry 51, n. 2 (2023): 51–56. http://dx.doi.org/10.33927/hjic-2023-18.
Testo completoAbstract (sommario):
In this study, a waterproof polyaspartic coating used for concrete structures was modified into an anti-corrosion coating system to prevent steel assets from corroding. A micaceous iron oxide barrier, a zinc phosphate corrosion inhibitor and a novel resin hardener were added to the polyaspartic coating. Its corrosion performance was assessed through immersion corrosion tests in 3.5% NaCl solutions at room temperature (RT) and 35 °C for 30 days. The surface finish of the steel samples was milled and blasted (SA 2.5). The coating was applied directly to the metal substrate. The average thickness of the coating was 220 ±10 µm. The experimental results confirmed the successful enhancement of the control coating on steel that was previously applied to concrete by adding a zinc phosphate corrosion inhibitor and micaceous iron oxide barrier. However, defects in the coating and rust on the substrate of the control coating were hindered by applying the developed coating.
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Rodriguez-Calvillo, Pablo, Lucia Suarez e Yvan Houbaert. "Al-Si-Fe Intermetallics on Fe-Substrates during Hot-Dipping". Defect and Diffusion Forum 297-301 (aprile 2010): 1042–47. http://dx.doi.org/10.4028/www.scientific.net/ddf.297-301.1042.
Testo completoAbstract (sommario):
Steels alloyed with Si and Al are used as core material in flux carrying machines, they are commonly called electrical steels, divided into grain oriented and non-oriented when a material without magnetic anisotropy or not is desired and used in transformer and electrical motors, respectively. The appearance of brittle ordered structures when Si+Al content in steel is above 4 m.-% does not always make its industrial production easy. Therefore hot dipping in a Al-Si bath followed by a diffusion annealing was found to be a productive way of steels with high Si and/or Al concentration and to overcome the creation of fragile structures during deformation processes, such as rolling. The formation of different layered Al-(Si)-Fe intermetallics on the steel substrate depends on diverse processing parameters such as bath temperature and composition, immersion time, preheating of the steel substrate and its composition and cooling down to room temperature. This contribution reports the diffusion kinetics of Fe2Al5 products obtained during the hot dipping process in an Al iron saturated and a hypoeutectic Al – 5 m.-% Si baths of ultra low carbon steel and Fe-substrates with 3 m.-% Si, annealed and cold rolled to different thicknesses. The preheating of the samples and bath temperatures were varied between 670 to750°C. Dipping times between 1 to 600 sec. were applied. The different layers and compounds formed were characterized by Scanning Electron Microscopy (SEM), using Back Scattered Electron (BSE) detector and Energy Dispersive Spectroscopy (EDS). The influence of the substrate and bath chemical composition on the growth kinetics of the Fe2Al5 intermetallics was investigated assuming a parabolic law. Si addition retards the growth kinetics and, as result, raises the activation energy from 71.3 to 159.8 kJmol-1, the obtained results are in agreement with the literature.
46
Goergen, Fabian, Dieter Mevissen, Stefano Masaggia, Enrico Veneri, Jens Brimmers e Christian Brecher. "Contact Fatigue Strength of Austempered Ductile Iron (ADI) in Gear Applications". Metals 10, n. 9 (25 agosto 2020): 1147. http://dx.doi.org/10.3390/met10091147.
Testo completoAbstract (sommario):
Austempered Ductile Iron (ADI) is widely implemented to achieve lightweight and optimized components in power transmissions (e.g., internal gear in planetary stages), by substituting steel castings or a combination of Ductile Iron and steel-assembled structures. In this paper, the contact fatigue of two ADI grades (ADI J/S900-8; ADI J/S1200-3) is investigated by disk-on-disk tests. The disk-on-disk contact is an analogy model of the tooth contact and represents the tribological conditions at a specific point on the path of contact. The experimental results cover the endurance limit as well as the short time fatigue behavior for both ADI variants. In addition, the pitting characteristics and microstructural changes are analyzed in order to get a further understanding of the fatigue behavior of ADI.
47
Petroselli, Chiara, Beatrice Moroni, Stefano Crocchianti, Roberta Selvaggi, Riccardo Vivani, Francesco Soggia, Marco Grotti, Francesco d’Acapito e David Cappelletti. "Iron Speciation of Natural and Anthropogenic Dust by Spectroscopic and Chemical Methods". Atmosphere 10, n. 1 (29 dicembre 2018): 8. http://dx.doi.org/10.3390/atmos10010008.
Testo completoAbstract (sommario):
In this work, we have characterized the iron local structure in samples of two different types of atmospheric dust using X-ray absorption spectroscopy and selective leaching experiments. Specifically, we have investigated samples of long-range transported Saharan dust and freshly emitted steel plant fumes with the aim of individuating possible fingerprints of iron in the two cases. Findings include (1) prevalence of octahedral coordinated Fe 3 + for all samples; (2) presence of 6-fold coordinated Fe 3 + , aluminosilicates and iron oxy(hydr)oxides in Saharan dust and (3) of Fe-bearing spinel-like structures in the industrial fumes; (4) general predominance of the residual insoluble fraction with a notable difference: 69% for Saharan dust and 93% for steel production emissions, associated with aluminosilicates and non-reducible iron oxy(hydr)oxides, and Fe spinels, respectively. The remarkable differences between the X-ray absorption spectroscopy (XAS) spectra and leaching test results for the two sample types suggest the possibility to exploit the present approach in more complex cases. To this aim, two additional case studies of mixed aerosol samples are presented and discussed.
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Chi, Jen Hao, e Peng Chi Peng. "A Study on Metallographic Microstructure of Steel Materials Subjected to Fire". Solid State Phenomena 263 (settembre 2017): 72–76. http://dx.doi.org/10.4028/www.scientific.net/ssp.263.72.
Testo completoAbstract (sommario):
In view of the fact that construction of modern buildings tends to use a high ratio of iron materials, this study aimed to obtain the ratio of components of steel’s microstructure under different test conditions by heating a A36 steel sheet commonly used in buildings, and applying metallographic replication testing. When the steel sheet was heated above 800°C and then rapidly cooled by water, the ratio of components of the structure were changed dramatically: components such as pearlite disappeared, ferrite was reduced from 90% to a low of 20%, bainite was increased to a maximum of 35%, and martensite was increased to a maximum of 45%. Since the substantial increase of martensite phase in this study led the microstructure of iron material to become thinned out and scattered, the ductility of such material was significantly reduced accordingly, thereby making the steel sheet easily broken. This study expected to provide the test findings of the mechanical behavior and metallographic structure of steel, after being heated to a high temperature and then naturally cooled, to other relevant units of construction engineering to serve as reference for their evaluation of non-destructive testing of steel structures.
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Piemonti, Alan, Antonio Conforti, Luca Cominoli, Sabrina Sorlini, Antonella Luciano e Giovanni Plizzari. "Use of Iron and Steel Slags in Concrete: State of the Art and Future Perspectives". Sustainability 13, n. 2 (8 gennaio 2021): 556. http://dx.doi.org/10.3390/su13020556.
Testo completoAbstract (sommario):
In the two last decades, world production of pig iron and steel has undergone a significant increase. In 2018, 1252.87 and 1806.46 million tons of pig iron and steel, respectively, were produced as compared to the 575.78 and 809.94 million tons of 2000. Consequently, the amount of the different types of slags deriving from these production processes has also increased considerably. In relation to the principles of sustainability and circular economy, the available literature suggests several possible reuses for these slags (bituminous conglomerates, hydraulic engineering, metallurgy, fertilizers, etc.). This paper aims to provide an overview of the iron and steel slags production and their reuse in concrete (for example as replacement of cement, fine or coarse aggregates). The characteristics of slags are analyzed in terms of chemical, physical, and mechanical properties. Mechanical and durability tests (both from material and structures point of view) carried out in the different studies and research are shown as well. Particular attention was devoted to electric arc furnace slags (EAF) since they are the most produced in Italy. Based on this deep literature review, the gaps that still require further studies have been identified and discussed.
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Zimmermann, Martina, Jörg Bretschneider, Gunter Kirchhoff, Uwe Stamm, Jens Standfuss e Berndt Brenner. "Fatigue Behaviour of Laser Beam Welded Circular Weld Seams under Multi-Axial Loading". Advanced Materials Research 891-892 (marzo 2014): 1397–402. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1397.
Testo completoAbstract (sommario):
With modern laser beam sources welding processes can be developed, that allow the joining of otherwise barely realisable material and geometrical constellations such as dissimilar welded, thick-walled shaft-hub joints for powertrain systems. Current design recommendations do not offer solutions to account for the cyclic strength under torsional loading for welded structures. In order to bridge the gap between cost and time consuming prototype testing and laboratory tests of basic homogeneous material samples, a test system combining axial and torsional loading was used. For this purpose application oriented test parts are designed to mimic the weld seam geometry, stiffness and heat dissipation conditions of the real structural part at its best. The dissimilar joints were realised for two material combinations: cast iron GJS-600-3 with case hardened steel 16MnCr5 and 42CrMo4 with 16MnCr5. The latter combination showed only a slightly higher cyclic strength compared to the cast iron/steel combination. A systematic optimization of the laser beam welding process leads to a fatigue behaviour under multi-axial loading conditions, where the cast iron/case hardened steel combination still met the strength specification required.