Mechanical Properties Of Stainless Steel Research Articles

Effect of high-temperature molten salt corrosion on the mechanical properties of stainless steel

The corrosivity of molten salt can be detrimental to the safe operation and longevity of concentrated solar thermal power generation equipment. Additionally, the presence of impurity Cl− can increase corrosion on metal materials, leading to mechanical property degradation. To assess the extent of this effect, the corrosion behaviour of three types of stainless steel (304, 316L, and 347H) in molten salt at high temperatures was studied using the loss-in-weight method and tensile tests. According to the findings, the Rdepths of 304, 316L, and 347H stainless steels are 0.0018 mm/a, 0.0016 mm/a, and 0.0019 mm/a, respectively, resulting in a decrease in elongation of 12.2%, 7.0%, and 3.7% after 720 h of corrosion at 600°C. Furthermore, at a higher temperature of 680°C, the Rdepths of all stainless steels increased, and the elongation decreased by 25.4%, 18.9%, and 13.5%, respectively. Similar corrosion behaviour was observed in 347H stainless steel with increased chloride ion concentration. However, the yield strength and tensile strength of stainless steel did not exhibit significant changes under different experimental conditions. The corrosion mechanism of metal alloys in molten salt is mainly due to the selective corrosion of Cr and its dissolution into molten salt in the form of ions.

Predicting the mechanical properties of stainless steels using Artificial Neural Networks

Abstract Knowing the material properties is of a crucial importance when planning to manufacture some structure. That is true for the steel structures, as well. Thus, for the proper planning of a certain steel part or a structure production, one must be aware of the properties of the material, to be able to make a qualified decision, which material should be used. Considering that the manufacturing of steel products is constantly growing in various branches of industry and engineering, the problem of predicting the material properties, needed to satisfy the requirements for the certain part efficient and reliable functioning, becomes an imperative in the design process. A method of predicting four material properties of the two stainless steels, by use of the artificial neural network (ANN) is presented in this article. Those properties were predicted based on the particular steels’ known chemical compositions and the corresponding material properties available in the Cambridge Educational System EDU PACK 2010 software, using neural network module of MathWorks Matlab. The method was verified by comparing the values of the material properties predicted by this method to known values of properties for the two stainless steels, X5CrNi18-10 (AISI 304), X5CrNiMo17-12-2 (AISI 316). The difference between the two sets of values was below 5% and, in some cases, even negligible.

Effect of Carburization on the Microstructure and Laser Weldability of 316L Stainless Steel

This study aims to investigate the influence of the carburizing layer on the microstructure of laser-welded joints in 316L stainless steel, aiming to enhance the properties of stainless steel components through the incorporation of carburization. Through a comprehensive experimental approach, including nanoindentation and Vickers hardness measurements, the microstructural analysis of the laser-welded specimens was conducted. The nanoindentation results reveal a significant increase in hardness, with the carburizing layer exhibiting a remarkable 215% improvement compared to the base material. In order to effectively harness the wear resistance for various applications, the examination of macroscopic characteristics in laser-welded joints reveals the necessity of regulating heat input and minimizing defects to attain welds of superior quality. Additionally, the phase transformation behavior of stainless steel during welding was found to be altered due to dilution in the fusion zone and the presence of high carbon content in the heat-affected zone of the carburizing layer. Overall, this research provides valuable insights into the microstructural changes induced by carburization and its implications for the welding performance and mechanical properties of stainless steel.

Analisis Pengaruh Komposisi Kimia dan Suhu Perlakuan Panas Terhadap Sifat Mekanik Baja Tahan Karat untuk Aplikasi Konstruksi

A deep understanding of the mechanical properties of stainless steel is crucial for designing constructions that meet the requirements. However, to comprehensively understand the mechanical properties of stainless steel, sufficient testing is needed to gather data regarding its characteristics. In this research, an analysis was conducted on the Effect of Chemical Composition and Heat Treatment on the Mechanical Properties of Stainless Steel, using data from the Material Algorithm Project (MAP), which is a material database. The data was analyzed using descriptive statistics and Pearson correlation to observe the relationships between these variables. The research results indicate that chemical elements such as Cu and Ni have a positive correlation with elongation, indicating that higher concentrations of these elements lead to higher elongation of stainless steel. Furthermore, it was also found that temperature has a strong negative correlation with yield strength (YS) and ultimate tensile strength (UTS), with correlation values of -0.71 and -0.86, respectively. Further analysis revealed that water quenching resulted in better ultimate tensile strength compared to air quenching. This research demonstrates that experimental material testing datasets not only validate experiments but can also actively be used in the analysis and design of more effective materials.

Development of Mechanical Properties of Stainless Steel 316LN-IG after Cryo-Plastic Deformation.

The article deals with increasing the mechanical properties of stainless steel 316 Ln-IG, which is intended for work in cryogenic temperatures (liquid nitrogen and liquid helium), such as conductor conduits for the ITER magnet system. The strength and plastic properties were increased by a combination of cold and cryo-rolling and heat treatment. The mechanical properties of rolled material were investigated at 293 K, 77 K, and 4.2 K. The work-hardening rate of the steel increased continuously with a lowering of the temperature. The maximum yield strength and ultimate tensile strength were achieved by the cryo-rolling process with a total thickness deformation of 50%. The material properties tested at ambient temperature were 0.2YS = 1050 MPa, UTS = 1200 MPa, and at 4.2 K, the values were 0.2YS = 1804 MPa and UTS = 2081 MPa. Two types of long-term heat treatment were applied after experimental rolling (823 K and 1093 K for 10 h). The highest precipitation hardening of steel was achieved at a temperature of 823 K after 50% deformation. The resulting grain size decreased from the initial 216 μm (before the rolling process) to 70 μm after ambient rolling and 72 μm after cryo-rolling.

Mechanical Properties of Austenitic Stainless Steel After Exposure to Elevated Temperature

Stainless steel has been widely used in the building industry as load-bearing elements such as beams and columns. Many fire accidents in stainless steel buildings were recorded, but only a few have collapsed entirely. These buildings can be rehabilitated and the undamaged parts can be reused, which reduces the economic losses in buildings exposed to fire. The residual mechanical properties of stainless steel after the fire, are the primary determinant of the validity of the stainless steel structure. In this paper, the effect of high temperatures and the time of exposure and cooling method on the mechanical properties of S304 stainless steel was studied. The specimens were heated to 800°C and 1000°C for different heating times (30, 60,90 and 120 minutes) and cooling methods (air-cooled and water-cooled). Results showed that the post-fire yield stress was reduced by 24% and 18% after heating to 800°C for 120minutes and cooled in water and air respectively. However, heating to 1000°C showed a marginal effect on the yield stress of air-cooled specimens and a clear reduction (29%) in the water-cooled specimens. Elongation capacity increased with heating time for 1000oC specimens but decreased for 800oC specimens in both cooling methods.

Investigation of the mechanical, tribological, and corrosion properties of 316L SS-HTC composites

ABSTRACT Many different additives have been used to improve the mechanical properties of stainless steel (SS) matrix materials. However, few studies are using carbonaceous additives. Among them, hydrothermal carbons (HTC), produced from biomass with a very low production cost and without any harmful chemicals, have not yet been tried. In this study, SS-HTC composites were produced by powder metallurgy using HTC in three different ratios. The effects of HTC content in the metal matrix on the mechanical, tribological, and corrosion tests are compared and discussed. According to the results of these tests, the best results of approximately 22% hardness value, 8% ultimate compressive strength, and 5% wear resistance increase were obtained with low HTC (0.25 wt%) use.

Effect of boron element on microstructure and mechanical properties of 316L stainless steel manufactured by selective laser melting

Boron(B)element is often utilized to enhance mechanical properties of stainless steel due to its excellent performance. In this study, selective laser melting (SLM) was used to print 316L/B stainless steel with varying boron weight content. The effects of boron content on microstructure, nanoindentation, and mechanical properties of the printed 316L stainless steel were discussed. Fine cell dendrites and columnar crystals were found in the SLM printed stainless steel due to the rapid solidification in SLM. It was found that boron has a higher growth limiting factor in the iron system and the boron solute can provide a high component supercooling. By adding boron element to stainless steel during printing, the honeycomb and grain size after solidification are significantly reduced due to interactions between the boron element and the 316L. Tensile testing results show that the ultimate tensile strength of the SLM fabricated parts with 0.5 wt% and 1 wt% boron element addition can be increased significantly to 1071 MPa and 1174 MPa, respectively.

Effect of paint removal with kilowatt level nanosecond pulsed laser on microstructure and mechanical properties of stainless steel

Effect of paint removal with kilowatt level nanosecond pulsed laser on microstructure and mechanical properties of stainless steel

Microstructure evolution, phase formation, corrosion, and mechanical properties of stainless steel fabricated by extrusion-based sintering-assisted additive manufacturing

Microstructure evolution, phase formation, corrosion, and mechanical properties of stainless steel fabricated by extrusion-based sintering-assisted additive manufacturing

Influence of Temperature and Deformation on Structure and Mechanical Properties of Stainless Steel

Influence of Temperature and Deformation on Structure and Mechanical Properties of Stainless Steel

A new approach to improve some properties of wire arc additively manufactured stainless steel components: Simultaneous homogenization and boriding

Arc-directed energy deposition (Arc-DED), also commonly referred to as wire arc additive manufacturing (WAAM), is a cost-effective 3D metal additive manufacturing process in which large metallic parts can be produced due to high deposition rates. Stainless steels, widely used in many areas due to their excellent corrosion resistance, are one of the most produced materials by the WAAM method. However, stainless steels have low surface hardness. Moreover, the high heat input in the deposition process in WAAM sometimes causes the mechanical properties of stainless steels to be lower than casting or wrought stainless steels. These considerations limit the use of WAAM stainless steels, especially in abrasive environments. For this purpose, 307ER stainless steel produced by WAAM method was subjected to homogenization and boriding process simultaneously at 1000 °C for 1 h and the effect of applied heat treatment on microstructure, phase components, hardness and wear resistance was investigated. The results showed that with the boriding process, a 30 μm thick boride layer consisting of FeB, Fe2B, Cr5B3 and MnB phases with a hardness of 21.5 GPa and a modulus of elasticity of 310 GPa was formed in addition to the dissolution of interdendritic regions in the as-built structure and a complete homogenization of the microstructure. Furthermore, owing to the high hardness and elasticity modulus in addition to the boride layer's self-lubrication properties obtained on the WAAM samples surfaces, 31.84 times and 8.06 times increased in wear resistance at room temperature and 500 °C temperature, respectively, and a decrease in friction coefficients was obtained. Moreover, the results showed that the simultaneous homogenization and boriding processes of stainless steels produced by the WAAM method would improve their microstructure and tribological behavior. This way, these steels can be used in wider areas of application.

Mechanical properties of stainless steel by using high temperature microhardness tester

In the aeronautical field, materials are used in severe environmental conditions (temperature, atmosphere), particularly for engine applications. In order to qualify new alloys compositions, ONERA is developing micromechanical characterization means to carry out indentation tests from room temperature up to 700 °C under conditions close to operating conditions. This method presents the interest of performing tests faster than classical mechanical tests like tensile or bending tests under severe conditions and with small amounts of materials. In order to carry out screening tests, a 316L stainless steel is studied and the evolution of hot Vickers hardness properties and yield stress versus temperature are presented. By increasing the applied load from 0.1 to 20 N, we show that we can neglect surface microstructural changes or possible contamination of the sample surface by oxidation. We show that from 0.5 N, the hardness measurement is independent of load on 316L stainless steel. By using Tabor’s law to express the mechanical resistance, we show that the hardness decreases by 50% when the test temperature goes from 20 to 700 °C, which is close to the supplier’s values. A discussion on the use of indentation to determine mechanical resistance and the limitations of this technique is presented. In perspective, these measurements could be carried out at 1000 °C and on many different materials such as layers, coatings, composite materials, brazing cords or additive manufacturing materials.

Selective Laser Melting and Mechanical Properties of Stainless Steels.

Metal additive manufacturing (AM) has been evolving in response to industrial and social challenges. However, new materials are hindered in these technologies due to the complexity of direct additive manufacturing technologies, particularly selective laser melting (SLM). Stainless steel (SS) 316L, due to its very low carbon content, has been used as a standard powder in SLM, highlighting the role of alloying elements present in steels. However, reliable research on the chemical impact of carbon content in steel alloys has been rarely conducted, despite being the most prevalent element in steel. Considering the temperatures involved in the SLM process, the laser-powder interaction can lead to a significant carbon decrease, whatever the processing atmosphere. In the present study, four stainless steels with increasing carbon content-AISI 316L, 630 (17-4PH), 420 and 440C-were processed under the same SLM parameters. In addition to roughness and surface topography, the relationship with the microstructure (including grain size and orientation), defects and mechanical properties (hardness and tensile strength) were established, highlighting the role of carbon. It was shown that the production by SLM of stainless steels with similar packing densities and different carbon contents does not oblige the changing of processing parameters. Moreover, alterations in material response in stainless steels produced under the same volumetric energy density mainly result from microstructural evolution during the process.

Mechanical properties of stainless steel QN1906Mo at sub-zero temperatures: Tests and stress–strain models

This paper made efforts on investigating low-temperature mechanical properties of new constructional stainless steel (SS) QN1906Mo. Forty-two tensile coupons were firstly tensioned at four low temperatures of 30, -30, -60, and -80 °C. Environment for testing low temperatures was realized through an insulation chamber with injecting LNG. The test results reported low-temperature mechanical properties of SS QN1906Mo materials and welds. Test results showed that decreasing the temperature from 30 to -80 °C did not affect the ductility and elastic Young’s modulus of SS QN1906Mo material, but significantly increased yield and ultimate strengths of SS QN1906Mo material by 37% and 35%. Decreasing the temperature from 30 to -80 °C also exhibited equivalent increments in yield or ultimate for weld coupons to those material coupons but with much larger scatters due to the air voids in the weld coupons. Finally, this paper developed constitutive models to describe stress–strain laws of SS QN1906Mo at varying T range of -80∼30 °C, which were proved their capabilities.

Effect of MIG Welding Parameters on the Mechanical Properties of AISI 304 Austenitic Stainless Steels

The present research investigates joints welding of 304L austenitic stainless steel using metal inert gas (MIG) welding method. The research explores the effect of process parameters (arc voltage, wire feed rate, and electrode wire diameter) on the mechanical properties of stainless steel. The above variables are varied respectively with 18.5, 19, 19.5 V, 116, 127, 137 mm/s, and 0.8, 1, 1.2 mm, with E308L as a filler electrode. The design matrix of the experiments was determined using the design of experiment (DOE) program Minitab 17 based on the levels of input elements used. The Taguchi orthogonal matrix methodology (Taguchi) technique was used to develop some empirical analysis for the maximum tensile strength and proper surface hardness as a function of the welding parameters mentioned above. The ( ) analysis was used to statistically verify the model's adequacy. The results show that the wire feed rate had the greatest effect on the tensile strength of the welded joints when choosing the medium level of arc voltage (19 V), while the arc voltage had a substantial influence on the micro-hardness of all welded joints. The weld-joint zone is given a higher micro-hardness value compared to the base metal zone.

Electrophoretic deposition of chitosan reinforced baghdadite ceramic nano-particles on the stainless steel 316L substrate to improve biological and physical characteristics

Despite the low cost and high mechanical properties of stainless steel (SS 316L) as orthopedic implants, it shows poor bioactivity and biocompatibility due to various corrosion mechanisms occurring in a biological environment. Therefore, this study is aimed at developing a novel nano-composite of chitosan-baghdadite nano-particles by electrophoretic technique to enhance the corrosion resistance, biocompatibility, and bioactivity properties of SS 316L implants. The results demonstrated that the applied Chitosan coating including 1 wt% baghdadite nano-particles at 15 V and 10 min was hydrophobic (44.26° ± 1.34) and it increased the roughness of SS 316L from 0.20 ± 0.01 μm to 1.47 ± 0.22 μm. Furthermore, increasing the baghdadite percentage affected coating adhesion. The evaluation of MG63 cell viability, spreading, and attachment verified no cytotoxicity, and well spreading and suitable attachment of MG63 cells on the coatings (optimum sample = coating with 1 wt% baghdadite nano-particles). This type of coating could provide appropriate biological properties for orthopedic implants based on the observed results.

Investigation of in-plane heat distribution, thermal stability and mechanical properties of SS-(Fe3O4)/Ti/AlN/Ti/SiO2 as absorber coatings for efficient high temperature concentrated solar power systems

Despite numerous achievements recorded so far in developing solar absorber coatings for photothermal applications, the study of the thermal stability in humid and cold environment remains very scarce and the underlaying physics behind the transfer of the absorbed energy to the working fluid has never been investigated. In this perspective, we developed Ti/AlN/Ti/SiO2 film as multilayer selective solar absorber coating (MSSAC) on Fe3O4 modified stainless steel substrate using Direct Current (DC)/Radio Frequency (RF) magnetron sputtering at room temperature. The coating exhibited solar absorptance of 0.969 and thermal emittance of 0.220 in the solar and infrared spectrum regions respectively. The MSSAC was found to be thermally stable up to 500 °C in air. Further increase in annealing temperature to 600 °C resulted to a slight decrease in solar absorptance from 0.969 to 0.953 and a small rise in the emittance value from 0.220 to 0.258. A high humidity test and rapid heating-cooling cycling (RHCC) test revealed the stability of this coating and its potential application in humid (90 mmHg) and cold (− 50 °C) environments. Additionally, the coating shows good adhesion strength even after humidity and RHCC tests. The in-plane heat distribution analysis using thermal infrared imaging camera illustrated that there is a good possible transfer of the absorbed heat to the working fluid due to high surface temperature exhibited by Ti/AlN/Ti/SiO2 coated modified stainless steel (SS) substrate than the other boundary conditions. Overall, these results indicate that the present coating has the potential application in both high temperature, humid and cold environments.

Effect of drawing and annealing on the microstructure and mechanical properties of 304 austenitic stainless steel wire

Plastic deformation at room temperature, and the proceeding heat treatments, are important processes for optimizing the microstructure and mechanical properties of austenitic stainless steel. The microstructure and mechanical properties of cold-drawn 304 austenitic stainless steel wire were investigated after annealing at 700 °C and 800 °C, with different times (20, 40 and 60 min) and drawing strain (0.4, 1.0 and 1.5). Electron backscattered diffraction (EBSD) techniques, transmission electron microscope (TEM) analysis, differential scanning calorimeter (DSC) and tensile tests were performed in order to study the microstructure evolution and mechanical properties during different annealing processes for the 304 austenitic stainless steel wire. The results showed that the quantity of α′ martensite and dislocations increased with an increase in the strain, which means that, while the ultimate tensile strength of the cold-drawn wires elevated, the elongation reduced. The mechanical properties of stainless steel wires also varied with the evolution of martensite transformation characteristics, density of stacking fault, dislocation and twin, as well as the recrystallization degree under various annealing conditions. The recrystallization temperature of steel wire was mainly determined by the magnitude of the strain, while the martensite reversal temperature was determined by the stacking fault energy and the deformation value. The temperature of recrystallization and martensite reverse in steel wire decreased with the increment of the strain. The balance of tensile strength and elongation of steel wire can be obtained by adopting the proper annealing process combined with cold-drawing deformation. In this paper, we showed that a good combination of strength and elongation in 304 austenitic stainless steel can be obtained with a strain of 1.5 annealed at 800 °C for 20 min.

Compression behaviour of stainless-steel stub square tubular columns at cold-region low temperatures

This paper studied the axial compression behaviour of stainless-steel stub square tubular columns (SSSSTCs) at low temperatures (T). Firstly, mechanical properties of stainless steel (SS) S30408 at −80–20 °C were experimentally studied. Test results revealed that decreasing low temperature significantly improved the strength of SS especially the ultimate strength, but reduced its ductility. Twenty SSSSTCs with varying wall thickness were tested at different T of −80–20 °C. Test results showed that inward and outward local buckling took place for SSSSTCs under low temperature-compression. The decreasing T value had significantly positive influence on strength and stiffness of SSSSTCs, but reduced the nonlinear branch of P-Δ curves and ductility of SSSSTCs. The increasing wall thickness significantly improves both strength and ductility of SSSSTCs at different low temperatures due to the reduced width-to-thickness ratio. This paper also developed finite element model (FEM) on simulating compression behaviour of SSSSTCs at different low temperatures that considered geometric imperfections and material nonlinearities. Different code prediction equations were also adopted for predictions of the ultimate low-temperature compression resistances of SSSSTCs. Their accuracies were checked by reported test results.