Готові списки джерел за темами / Super 304H Austenitic Stainless Steel

Добірка наукової літератури з теми "Super 304H Austenitic Stainless Steel"

Автор: Grafiati

Опубліковано: 6 вересня 2023

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Статті в журналах з теми "Super 304H Austenitic Stainless Steel"

LEE, HAN-SANG, BUM-SHIN KIM, and SUN IG HONG. "Comparison of Stress Relaxation Cracking Susceptibility of Austenitic Stainless Steels." Welding Journal 101, no. 9 (September 1, 2022): 225–39. http://dx.doi.org/10.29391/2022.101.017.

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Coal-fired power plants often have welded joints made up of 347H stainless steel. However, this alloy is known to fail because of stress relaxation cracking. Thus, quantitative evaluation methods are needed as screening measures. In this study, a Gleeble® thermomechanical simulator was implemented in 347H and Super 304H alloy heat-affected zone (HAZ) simulation and stress relaxation testing. In the case of 347H, carbide dissolution in the HAZ reduced the hardness value and promoted grain growth. Alternatively, the respective extent of precipitate dissolution and hardness reduction in the nitrogen-containing Super 304H was relatively small. The stress relaxation tests were performed at a temperature of 700°C (1292°F), which was maintained for up to 70 h. Consequently, all 347H specimens fractured within 32 h. Furthermore, the time to rupture substantially decreased as the strain was increased from 5 to 10% and then to 15%. Additionally, the hardness near the fractured surface increased, and the plastic deformation primarily occurred near the grain boundaries. Conversely, the Super 304H specimens did not fracture during the 70-h testing period, at which time their hardness distribution was observed to still be relatively uniform. These results demonstrate that the susceptibility of stress relaxation cracking can be quantitatively determined according to the material and strain.

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Zhong, Fei, Chunlei Zhang, Wensheng Li, Jingpin Jiao, and Liqiang Zhong. "Nonlinear ultrasonic characterization of intergranular corrosion damage in super 304H steel tube." Anti-Corrosion Methods and Materials 63, no. 2 (March 7, 2016): 145–52. http://dx.doi.org/10.1108/acmm-05-2014-1390.

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Purpose – Super304H steel is a new fine-grained austenitic heat-resistant stainless steel developed in recent years, and it is widely used in high temperature section superheater and reheater tubes of ultra-supercritical thermal power units’ boiler. Currently intergranular corrosion (IGC) has occurred in a few austenitic stainless steel tubes in ultra-supercritical units and led to boiler leakage. The purpose of this paper is to find a nondestructive method to quickly and easily detect IGC of austenitic stainless steel tube. Design/methodology/approach – This paper uses the nonlinear characteristics of ultrasonic propagation in steel tube to detect the IGC of Super304H tube. Findings – The experimental results show that the nonlinear coefficient generally increases sensitively with the degree of IGC; hence, the nonlinear coefficient can be used to assess IGC degree of tubes, and the nonlinear coefficient measurement method is repeatable for the same tube. Research limitations/implications – A theory of how IGC would affect the ultrasonic signals and lead to a nonlinear response needs further research. Practical implications – A nondestructive method to quickly and easily detect IGC is provided. Social implications – Using ultrasonic nonlinear coefficient to assess IGC degree of tubes is a new try. Originality/value – This paper provides a new way to test IGC.

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Prabha, B., P. Sundaramoorthy, S. Suresh, S. Manimozhi, and B. Ravishankar. "Studies on Stress Corrosion Cracking of Super 304H Austenitic Stainless Steel." Journal of Materials Engineering and Performance 18, no. 9 (December 2009): 1294–99. http://dx.doi.org/10.1007/s11665-008-9347-9.

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Pavan, A. H. V., R. Ravibharath, and Kulvir Singh. "Creep-Rupture Behavior of SUS 304H – IN 617 Dissimilar Metal Welds for AUSC Boiler Applications." Materials Science Forum 830-831 (September 2015): 199–202. http://dx.doi.org/10.4028/www.scientific.net/msf.830-831.199.

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Advanced Ultra Super-Critical (AUSC) power plants are envisaged for achieving higher thermodynamic efficiency by operating at temperatures and pressures of 710/720 °C and 310 ata, respectively which are significantly higher than sub-critical (conventional) and supercritical power plants. This has led to tremendous research in selection of new and advanced materials to meet high temperature requirements. Ni-base superalloys having known to have excellent creep-rupture behavior were selected for high temperature sections of boiler while austenitic stainless steels were selected for moderately high temperature sections considering the economical feasibility. Since both these materials have to be fabricated for application in boiler tubes, dissimilar metal welding is inevitable. This work discusses creep-rupture evaluation of one such case of dissimilar welds, i.e., between Inconel 617 (IN 617) and SUS 304H. IN 617 is a Ni-base superalloy while SUS 304H is a Cu-precipitated austenitic stainless steel. Welding was carried out using IN 617 filler material for producing defect free welds. Creep-rupture samples were prepared incorporating the complete cross-weldment for understanding mechanical behavior as a result of prolonged exposure to elevated temperature and stresses. Creep-rupture testing was carried out at 600, 650 and 700°C at suitable stresses to obtain rupture times in the excess of 3000 hours in a few test conditions. Detailed characterization studies when carried out on ruptured samples revealed the weakest zone to be heat affected zone towards SUS 304H which led to failure. This work also provides insight into the possible creep-mechanisms that operate in various zones of weldments. Phases formed as a result of exposure to stress and temperature for a prolonged duration are also discussed. Comparison of the data obtained with data available in literature was carried out and performance of weldments was analyzed and reported.

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Hong, Sung Min, Dong Joon Min, and Eric Fleury. "Effect of Grain Boundary Serration on the Tensile Properties of the Super 304H Heat Resistant Austenitic Stainless Steel." Materials Science Forum 654-656 (June 2010): 170–73. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.170.

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Grain boundary serrations were produced in heat-resistant austenitic stainless steel containing Cu by applying after solution heat-treatment a holding time in the range 700-800oC between 30 minutes to 3 hours. These special treatments provide an enhancement of the tensile ductility of about 40 and 113%at room temperature and 750oC, respectively, while no significant change in the yield stress and tensile strength could be observed.

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Pilsová, Lucie, Marie Ohanková, Vladimír Mára, Jan Krčil, and Jakub Horváth. "Effect of Internal Pressure on Microstructural and Mechanical Properties of X10CrNiCuNb18-9-3 (SUPER 304H) Austenitic Stainless Steel." Procedia Structural Integrity 43 (2023): 294–99. http://dx.doi.org/10.1016/j.prostr.2022.12.274.

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Li, Ping, Ting-ju Li, Jie Zhao, and Sheng-jiao Pang. "Hot corrosion behaviors of Super 304H austenitic stainless steel pre-coated in Na2SO4–25%NaCl mixture salt film." Journal of Iron and Steel Research International 25, no. 11 (October 19, 2018): 1149–55. http://dx.doi.org/10.1007/s42243-018-0161-9.

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San, X. Y., B. Zhang, B. Wu, X. X. Wei, E. E. Oguzie, and X. L. Ma. "Investigating the effect of Cu-rich phase on the corrosion behavior of Super 304H austenitic stainless steel by TEM." Corrosion Science 130 (January 2018): 143–52. http://dx.doi.org/10.1016/j.corsci.2017.11.001.

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Adijāns, I., L. Lazov, M. Ilieva, and M. P. Nikolova. "Investigation of the change in wettability properties and corrosion behavior of AISI 304 after laser surface texturing." Journal of Physics: Conference Series 2487, no. 1 (May 1, 2023): 012040. http://dx.doi.org/10.1088/1742-6596/2487/1/012040.

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Abstract Stainless steel is a widely used material in industry, architecture, and medical instruments. However, after various thermal processing of stainless steels, chromium carbides can be formed, which locally depletes the chromium available to form a passive film and reduces the corrosion performance. Laser surface treatment can change the surface chemistry of the steel and improve some electrochemical characteristics. However, these characteristics are influenced by the laser power, pulse width, distance between the lines, scanning speed, etc., which all change the surface chemistry and characteristics of laser surface texturing. Simultaneously, the ability to repel liquids that cause corrosion actions could combine to enhance corrosion performance. Since the wettability of a solid surface depends both on its topography and chemical nature, the micro structuring of an austenitic steel surface is an effective way of fabricating hydrophobic or super hydrophobic corrosion-resistant surfaces. For this reason, this study discusses the effect of laser power in the impact zone and the distance between raster lines on the microstructure, wettability, and corrosion resistance of austenitic steel (AISI 304) when exposed to nanosecond fiber laser radiation. The results indicate that parameter-controlled micro structuring can be used to form both hydrophilic and hydrophobic surfaces with different electrochemical performances.

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Wu, Guang Feng, Xiao Bin Zhang, and Wei Wu. "Microstructure and Corrosion Resistant Property Research of Super 304H and TP347H Heat-Resistant Steel Welding Joint." Advanced Materials Research 295-297 (July 2011): 1402–7. http://dx.doi.org/10.4028/www.scientific.net/amr.295-297.1402.

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Microstructure of Super 304H and TP347H austenitic heat resistance steel welding joint by handwork argon tungsten-arc welding and electro-chemical corrosion property of weld metal and two base materials were investigated by SEM and M273 constant potential rectifier. The results shows that microstructure of the weld metalwere austenitic matrix + δ ferrite; In 5% HCl Solution, corrosion resistant capabilities were super 304H base material＞ weld metal＞TP347H base material; in 9.8% H2SO4 Solution, corrosion resistant capabilities were Super 304H base material＞TP347H base material＞ weld metal; Super 304H and TP347H austenitic heat resistance steel welding joint has better corrosion resistant property in HCl solution than in H2SO4 solution; Inter-crystalline corrosion results were consistence to results electro-chemical corrosion experiment in 9.8% H2SO4 solution.

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Дисертації з теми "Super 304H Austenitic Stainless Steel"

Tossey, Brett M. "Steam Oxidation Resistance of Shot Peened Austenitic Stainless Steel Superheater Tubes." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306261300.

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Alsarraf, Jalal. "Hydrogen embrittlement susceptibility of super duplex stainless steels." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/4562.

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This thesis describes the metallurgical and environmental factors that influence hydrogen embrittlement of super duplex stainless steels and presents a model to predict the rate at which embrittlement occurs. Super duplex stainless steel has an austenite and ferrite microstructure with an average fraction of each phase of approximately 50%. An investigation was carried out on the metallurgical and environmental factors that influence hydrogen embrittlement of super duplex stainless steels. Tensile specimens of super duplex stainless steel were pre-charged with hydrogen for two weeks in 3.5% NaCl solution at 50º C at a range of applied potentials to simulate the conditions that exist when subsea oilfield components are cathodically protected in seawater. The pre-charged specimens were then tested in a slow strain rate tensile test and their susceptibility to hydrogen embrittlement was assessed by the failure time, reduction in cross-sectional area and examination of the fracture surface. The ferrite and austenite in the duplex microstructures were identified by analysing their Cr, Ni, Mo and N contents in an electron microscope, as these elements partition in different concentrations in the two phases. It was shown that hydrogen embrittlement occurred in the ferrite phase, whereas the austenite failed in a ductile manner. An embrittled region existed around the circumference of each fracture surface and the depth of this embrittlement depended on the hydrogen charging time and the potential at which the charging had been carried out. The depth of embrittlement was shown to correlate with the rate of hydrogen diffusion in the alloy, which was measured electrochemically using hydrogen permeation and galvanostatic methods. A two-dimensional diffusion model was used to calculate the hydrogen distribution profiles for each experimental condition and the model could be employed to provide predictions of expected failure times in stressed engineering components.

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Pramanik, Aparajita. "Effect of Copper on Strength of Super 304H Austenitic Stainless Steel." Thesis, 2018. http://etd.iisc.ac.in/handle/2005/4138.

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Super 304H is a copper-containing austenitic stainless steel with potential applications in advanced thermal power plants owing to its superior corrosion, oxidation, creep resistances and cost affordability. The addition of copper has been reported to improve high temperature strength and creep resistance of 304H, but with a loss of room temperature strength. The causes of this effect are not well understood since addition of copper affects several microstructural features simultaneously. The aim of this work is to shed light on the key microstructural effects of copper on mechanical response at room and high temperatures. Towards this aim, the effect of copper addition on the mechanical and microstructural properties of three alloys based on 304H and with three different levels (1, 3 and 5wt. %) of Cu was studied. These alloys were given solution and ageing treatments. Mechanical properties of the heat-treated alloys were evaluated by means of room temperature hardness measurements and constant strain rate tests at room temperature and 6500C. Microstructural characterization was conducted on undeformed and deformed samples by SEM-EBSD, XRD, TEM and 3dAP. It was found that in the as-solutionized condition, yield stress, hardness and strain hardening decreased on small additions of Cu (upto 3%), but increased on further additions. Significant enhancement in the room and high temperature strength was achieved on ageing, but only in alloys with 3 and 5% Cu. 3dAP and TEM studies confirm the presence of ultrafine (<10nm) copper precipitates in 3Cu and 5Cu alloys in both as-solutionised and aged conditions, with a higher volume fraction and number density in the aged alloys. TEM also reveals extensive interactions between Cu precipitates and dislocations in both undeformed and deformed samples. The effect of copper content and heat treatment on strength can be justified by accounting for two effects: copper solute softening due to suppression of strain-induced martensite formation and, copper precipitate strengthening due to lattice and modulus mismatch between the copper precipitates and the matrix. Dissolution of Cu precipitates on grain boundaries during solution treatment results in abnormal grain growth and changes twin boundary fraction as well. However, these microstructural changes due to copper addition have only a secondary effect on mechanical properties.

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Частини книг з теми "Super 304H Austenitic Stainless Steel"

Yoo, Y. R., H. Y. Chang, Yong Bum Park, Y. S. Park, Tai Joo Chung, and Y. S. Kim. "Influence of Thermal Treatment on the Caustic SCC of Super Austenitic Stainless Steel." In Materials Science Forum, 4227–30. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-960-1.4227.

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Han, Tingting. "Study on Material Corrosion Resistance of Flue Gas Waste Heat Exchanger." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220419.

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According to the statistics of China Electricity Council, about 97% of China’s coal-fired power generating units adopted wet desulfurization process (WFGD), of which the limestone-gypsum wet desulfurization process is the main process, accounting for about 91% of coal generating units. Without GGH, chimney exports can form white smoke plume. To solve the problem of environmental protection of white smoke plume and boiler flue gas waste heat recovery, the heat exchanger will be applied in flue gas condensation. But, the SO2, CO2, HCl and other complex components in flue gas can lead to equipment serious corrosion, so, it is necessary to study the heat exchanger and chimney material’s corrosion resistance. In this paper, the natural corrosion experiments in the actual chimney condensate of 2205 duplex stainless steel, 2507 super duplex stainless steel, 316L austenitic stainless steel and TA2 materials were studied by hanging weight loss method and electrochemical method at different temperatures. The results show that: The existence of weld in stainless steel and TA2 will increase the corrosion tendency and corrosion rate of the material. In static immersion, the higher the temperature, the higher the corrosion rate; Corrosion rate is 2507<2205< TA2< 316L; In the presence of SO42- and F-, the oxide film of TA2 is destroyed and its corrosion resistance is reduced, which provides a certain reference for material selection of heat exchangers and chimneys.

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Тези доповідей конференцій з теми "Super 304H Austenitic Stainless Steel"

Khanna, A. S., K. Sridhar, and M. B. Deshmukh. "High Performance Super-Austenitic Surface Alloy Using Plasma Coating and Laser Treatment." In ITSC 1997, edited by C. C. Berndt. ASM International, 1997. http://dx.doi.org/10.31399/asm.cp.itsc1997p0511.

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Abstract Stainless Steels are required for many applications for ship building as well as for offshore structures such as oil exploration. AISI type 304 stainless steel is not very suitable for such applications as it has a strong tendency for pitting and crevice corrosion. Even type 316 and 317 stainless steels which have respectively 2.5 and 3.5% Mo are not very effective in these environments. Commercially available stainless steels, viz., Avesta 254 SMO is being employed for such applications because of its strong resistance to pitting and crevice corrosion. This is mainly because of high Mo concentration (6.5%). Such steels are not only costly but are prone to form deleterious phases such as delta ferrite and sigma during welding or other heat treatment operations. Hence, an alternative technique to restrict Mo at the surface is needed. In the present work, surface alloys consisting of an austenitic stainless steel with Mo content as high as 10-12% have been formed on stainless steel type 304 substrates. These steels show enhanced passivity and strong resistance to pitting corrosion.

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Dalal, Mitul, and Jorge Penso. "Duplex Stainless Steel – Learning From Field Experience in Oil & Gas and Petrochemical Services." In ASME 2022 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/pvp2022-84889.

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Abstract Duplex stainless steels are a family of stainless steels. Named duplex (or austenitic-ferritic) grades because their metallurgical structure consists of two phases, austenite, and ferrite in approximately equal proportions. They are expected to provide better corrosion resistance, particularly chloride stress corrosion and chloride pitting corrosion, and higher strength than standard austenitic stainless steels such as Type 304 or 316. They are therefore used extensively in the offshore oil and gas and in the petrochemical industry in the form of piping and pressure vessels. This paper describes some applications that ended up in failures and the importance to adhere to tight fabrications fabrication controls and consider the effect of common manufacturing and fabrication deviations in the expected material performance. The first one is a shell and tube heat exchanger. On the shell side the material choice was 2205 duplex stainless steel. The shell side fluid is fed from debutanizer which feeds from upstream high pressure and low-pressure low temperature separators. Overhead stream contains H2S, NH3, HCl. The duplex was selected for this exchanger to mitigate potential dew point NH4Cl corrosion. The shell ended up leaking in less than two years after being placed in service. The second case is a super duplex 2507 seawater filter which failed after few weeks in service. Qualified welding procedures were not properly followed during fabrication leading to impaired corrosion resistant weldments. The third case describes one more failure of a hydrocracker reactor effluent air cooler. Tube to tubesheet and partition plates to tubesheet welds failed after ∼ 20 years in service.

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Takakuwa, Osamu, Junichiro Yamabe, Hisao Matsunaga, Yoshiyuki Furuya, and Saburo Matsuoka. "Recent Progress on Interpretation of Tensile Ductility Loss for Various Austenitic Stainless Steels With External and Internal Hydrogen." In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-65671.

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Slow-strain rate tensile (SSRT) tests on various metals having γ-Fe phase; Type 304 and 316L stainless steels, HP160 high strength stainless steel, and A286 Fe-based super alloy were conducted in external hydrogen and with internal hydrogen. The external hydrogen indicates non-charged specimens tested in high-pressure hydrogen-gas environment, whereas the internal hydrogen indicates hydrogen-charged specimens, with uniform distribution of hydrogen, tested in inert gas. The hydrogen distribution was calculated based on the measured hydrogen diffusivity and solubility. The fracture morphologies were observed by scanning electron microscopy (SEM). For Types 304, 316L, and HP160, the relative reduction in area (RRA) of the steels was successfully reproduced by the nickel equivalent, Nieq, showing the higher Nieq, the lager RRA. Furthermore, at a low Nieq, the RRA of the steel with external hydrogen was nearly equal to that with internal hydrogen. In contrast, at a high Nieq, the RRA of the steel with internal hydrogen was slightly degraded by hydrogen, RRA ≈ 0.8, whereas that in external hydrogen was not degraded, RRA ≈ 1. For A286, despite a high Nieq, the RRA of the alloy with internal hydrogen was significantly degraded by hydrogen, RRA ≈ 0.5. The fracture morphologies were categorized into four types: quasi-cleavage fracture associated with hydrogen-assisted surface cracks; ordinary void formation with no hydrogen effect; small-void formation associated with void sheet enhanced by hydrogen; facet formation induced by hydrogen. These categorized morphologies could be interpreted in terms of hydrogen distribution (internal or external hydrogen), austenitic stability (a low or high Nieq), and microstructure (solution or precipitation-hardened treatment).

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Rodrigo Pinto de Siqueira, José Flávio Silveira Feiteira, Vitor Brandão de Melo, Jefferson Fabrício Cardoso Lins, and Dionísio José R. da Costa. "Investigation of the grain growth evolution in the AISI 304H austenitic stainless steel." In 23rd ABCM International Congress of Mechanical Engineering. Rio de Janeiro, Brazil: ABCM Brazilian Society of Mechanical Sciences and Engineering, 2015. http://dx.doi.org/10.20906/cps/cob-2015-0606.

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Svensson, Eric, and Michael Catapano. "Evaluation of the Tube to Tubesheet Joining Process in an AL6XN® Feedwater Heater." In ASME 2017 Power Conference Joint With ICOPE-17 collocated with the ASME 2017 11th International Conference on Energy Sustainability, the ASME 2017 15th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2017 Nuclear Forum. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/power-icope2017-3190.

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Type 304 austenitic stainless steel is the most common tube material utilized for nuclear feedwater heaters, however, some utilities have experienced problems with Stress Corrosion Cracking (SCC), especially when they utilize brackish cooling water and have experienced condenser tube leaks. This has forced some utilities to explore other options when it comes to high pressure feedwater heaters (HP FWH) tubing materials. AL6XN® is considered a “super” stainless steel that is resistant to (SCC), however, it is not immune (AL6XN is a trademark of ATI Technologies). Based on the relative inexperience and unknowns related to the use of AL6XN tubing in high pressure, nuclear feedwater heater applications, a detailed mock-up procedure was outlined as part of the replacement heater specification which would allow the evaluation of the tube to tubesheet joining processes. Since AL6XN can still be affected by SCC; steps were taken in order to minimize the imposed stress levels and any potential for the inadvertent inclusion of contaminants during the fabrication steps at the tube mill and at the feedwater heater Manufacturer’s shop. The desire to minimize stresses also applies at the tube to tubesheet joint, therefore, it was desired not to stress the tube more than absolutely necessary in achieving a reliable, leak tight joint. The mock-up details and procedures were therefore generated with these objectives in mind, so as to give consideration for the ability to check different configurations in order to determine the most efficient tube to tubesheet joining process. Several tubes in the mock-up were subjected to a pull out test in order to quantify the joint strength in the different configurations. The mockup was then sectioned and inspected under a digital microscope to verify intimate contact between the tube and the tubesheet. Once the optimal procedure was identified, four identical HP FWHs were constructed utilizing AL6XN tubing. During heater production, over 30,000 tube ends were expanded, however, two tubes were identified to have failures as part of the tube expansion process. This paper shall describe the procedures utilized in developing and analyzing the tubesheet mock-up as well the actions taken to identify the root causes of the tube failures.

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Polishetty, Ashwin, Mohanad Fakhri Abdulqader Alabdullah, Nihal Pillay, and Guy Littlefair. "A Preliminary Study on Machinability of Super Austenitic Stainless Steel." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-50224.

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Stainless steel is the most widely used alloys of steel. The reputed variety of stainless steel having customised material properties as per the design requirements is Duplex Stainless Steel and Austenitic Stainless Steel. The Austenite Stainless Steel alloy has been developed further to be Super Austenitic Stainless Steel (SASS) by increasing the percentage of the alloying elements to form the half or more than the half of the material composition. SASS (Grade-AL-6XN) is an alloy steel containing high percentages of nickel (24%), molybdenum (6%) and chromium (21%). The chemical elements offer high degrees of corrosion resistance, toughness and stability in a large range of hostile environments like petroleum, marine and food processing industries. SASS is often used as a commercially viable substitute to high cost non-ferrous or non-metallic metals. The ability to machine steel effectively and efficiently is of utmost importance in the current competitive market. This paper is an attempt to evaluate the machinability of SASS which has been a classified material so far with very limited research conducted on it. Understanding the machinability of this alloy would assist in the effective forming of this material by metal cutting. The novelty of research associated with this is paper is reasonable taking into consideration the unknowns involved in machining SASS. The experimental design consists of conducting eight milling trials at combination of two different feed rates, 0.1 and 0.15 mm/tooth; cutting speeds, 100 and 150 m/min; Depth of Cut (DoC), 2 and 3 mm and coolant on for all the trials. The cutting tool has two inserts and therefore has two cutting edges. The trial sample is mounted on a dynamometer (type 9257B) to measure the cutting forces during the trials. The cutting force data obtained is later analyzed using DynaWare supplied by Kistler. The machined sample is subjected to surface roughness (Ra) measurement using a 3D optical surface profilometer (Alicona Infinite Focus). A comprehensive metallography process consisting of mounting, polishing and etching was conducted on a before and after machined sample in order to make a comparative analysis of the microstructural changes due to machining. The microstructural images were capture using a digital microscope. The microhardness test were conducted on a Vickers scale (Hv) using a Vickers microhardness tester. Initial bulk hardness testing conducted on the material show that the alloy is having a hardness of 83.4 HRb. This study expects an increase in hardness mostly due to work hardening may be due to phase transformation. The results obtained from the cutting trials are analyzed in order to judge the machinability of the material. Some of the criteria used for machinability evaluation are cutting force analysis, surface texture analysis, metallographic analysis and microhardness analysis. The methodology followed in each aspect of the investigation is similar to and inspired by similar research conducted on other materials. However, the novelty of this research is the investigation of various aspects of machinability and drawing comparisons between each other while attempting to justify each result obtained to the microstructural changes observed which influence the behaviour of the alloy. Due to the limited scope of the paper, machinability criteria such as chip morphology, Metal Removal Rate (MRR) and tool wear are not included in this paper. All aspects are then compared and the optimum machining parameters are justified with a scope for future investigations.

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Kalnaus, Sergiy, Feifei Fan, and Yanyao Jiang. "Fatigue and Cyclic Plasticity Properties of a Super-Austenitic Stainless Steel." In ASME 2007 Pressure Vessels and Piping Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/pvp2007-26478.

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Tension-compression, torsion and axial-torsion experiments were conducted on AL-6XN® alloy. The main goal was to investigate experimentally, in detail, the cyclic plasticity behavior as well as fatigue life of AL-6XN® steel. Details of cyclic stress-strain response were collected during the experiments, which can serve as a baseline for development of cyclic plasticity model for this material. Microscopic observations of cracking behavior conducted in the present study allow connecting the fracture mechanism with fatigue life prediction. It was observed, that fatigue life of this material is a function of the fracture mode (mixed or tensile). The mixed cracking was observed in the specimens tested under higher applied strain levels, while the tensile cracking was revealed in the tests under lower strain amplitudes. Strain-life curves of the specimens failed in mixed mode and of those failed in tensile mode run parallel to each other, but the specimens that exhibit mixed failure mode show lower fatigue life as compared to the tensile mode specimens. Transition between mixed and tensile cracking orientations was studied in detail. The results of the experimental work presented in this study can serve for design of fatigue models for this material in the future.

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O’Donnell, Dave, Nicole Karlen, and Carl Kettermann. "Performance Implications of High Energy Density Welding of Corrosion Resistant Alloy Heat Exchanger Tubing." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25165.

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The advent of Laser Beam Welding (LBW) has had a significant impact on resultant metallurgical performance of stainless steel welded heat exchanger tubing. While productivity enhancements are well recognized the metallurgical benefits are not. The low total heat input combined with the very high energy density results in ultra-fast quenching of molten metal, super-cooling past normal primary ferrite solidification in common 304/304L and 316/316L grades directly to austenite resulting in weldments with no retained delta ferrite and some inherent corrosion advantages. The same low total heat input and high energy density generates dramatically smaller dendrite spacing making subsequent homogenization by the combined efforts of cold work and solution annealing dramatically more effective. It should be recognized that this paper deals with issues relating to tube production where welds are autogenous or made without filler metal addition and are subsequently cold worked and solution annealed. Resulting benefits of laser welding include a seamless metallographic appearance, and improved field performance. The benefits and limitations of these enhancements are explored relative to other common stainless steel grades, as are alloy characteristics affecting performance.

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Minami, Yusuke, and Toshihiko Fukui. "Properties and Experience of High Cr Austenitic Stainless Steel for Boiler Tubes." In ASME 2007 Pressure Vessels and Piping Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/creep2007-26300.

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Recent boilers for thermal power generation are designed for higher temperature and pressure than in the past, and substantial efforts are being made worldwide to establish technology for ultra super critical power plants. Such boilers will require the use of steels having higher strength and better corrosion resistance than conventional 18-8 austenitic stainless steels. High chromium austenitic stainless steel (22Cr-15Ni-Nb-N) has been developed as a candidate material, and creep rupture strength is more than 50% higher than ASME SA-213 Grade TP347H at 700°C. The hot corrosion and steam oxidation resistance of this steel are also superior to 18-8 stainless steels due to higher Cr content. Thirteen years practical service as superheater tubing in a power plant characterized by high pressure (35MPa) and high temperature (615&°C) has revealed that the mechanical properties and environmental resistance of this steel are sufficient for high temperature boiler tube applications.

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McRae, D. M., R. P. Walsh, E. N. C. Dalder, S. Litherland, M. Trosen, and D. J. Kuhlmann. "Fatigue and fracture properties of a super-austenitic stainless steel at 295 K and 4 K." In ADVANCES IN CRYOGENIC ENGINEERING: Transactions of the International Cryogenic Materials Conference ICMC Volume 60. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4860605.

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