Manganese Austenitic Stainless Steel Research Articles

Research on the high-temperature oxidation properties of high-Mn and low-Ni austenitic stainless steel containing an aluminizing layer

High manganese (Mn) austenitic stainless steel substitutes expensive nickel (Ni) with more affordable Mn, thereby reducing production costs. However, its resistance to high-temperature oxidation is significantly compromised due to the formation of unstable Mn-rich oxides. To address this issue, this study investigates the application of an aluminizing layer on Fe–14Cr–10Mn-1.57Ni austenitic stainless steel to enhance its high-temperature oxidation resistance. The aluminized steel demonstrated a remarkable reduction in oxidation rate, with the surface oxidation rate constant being three orders of magnitude lower than that of the unaluminized stainless steel after exposure to 750 °C for 500 h. This improvement is attributed to the formation of a dense Al₂O₃ protective layer, which significantly enhances oxidation resistance. Furthermore, the study reveals a gradient in oxidation resistance between the aluminized surface and the core material, a phenomenon not previously reported in high-Mn, low-Ni steels. The primary oxidation mechanism is driven by the dense Al₂O₃ layer, which acts as a barrier, preventing the diffusion of oxygen to the steel substrate. These findings provide a cost-effective solution for enhancing the high-temperature durability of stainless steels, with potential applications in industries requiring materials with improved oxidation resistance, such as power plants and high-temperature furnaces.

In-situ strain induced martensitic transformation measurement and consequences for the modeling of medium Mn stainless steels mechanical behavior

This work aims at studying the control of medium manganese austenitic stainless steels’ mechanical behavior and austenite to martensite transformation via chemical composition. Six grades of austenitic stainless steel were cast with chemical compositions variations small enough able to keep relatively constant the stacking fault energy (SFE) value, but high enough to change the martensitic start temperature Ms. These experiments allow the effect of the martensite transformation on the mechanical behavior in tension to be compared while the austenitic mechanical behavior is almost unchanged. Tensile tests were performed at room temperature and at a low strain rate (10−4 s−1). In-situ magnetic measurement is implemented to quantify the martensite volume fraction evolution with strain. Strain heterogeneities are detected by digital image correlation (DIC) analysis. For all grades, stress–strain curves exhibit Portevin–le-Châtelier (PLC) phenomenon related to localized martensite transformation within the deformation bands. For the two most unstable alloys, a Lüders plateau is detected at the yield stress. The martensite evolution is modeled using the Olson–Cohen approach, which confirms slower kinetics for the most stable grades. Moreover, it is shown that the martensite fraction evolves linearly with stress after a stress threshold function of the austenite stability represented by Ms. The martensite volume fraction vs stress slope is constant whatever the composition. This result leads to the development of a coupled metallurgical/mechanical model which depends on a single parameter Ms related to the chemical composition.

The Effect of Cold Work and Thermal Aging on Intergranular and Transgranular Corrosion Failure of High Manganese Austenitic Stainless Steel

The Effect of Cold Work and Thermal Aging on Intergranular and Transgranular Corrosion Failure of High Manganese Austenitic Stainless Steel

Develop a sustainable welding procedure for chromium manganese austenitic stainless steel using the ATIG process

Chromium manganese austenitic stainless steel is exhibiting an admirable amalgamation of higher strength and stress corrosion resistance. This economical steel is developed to fulfill the requirement of a variety of consumers for high temperature and structural applications. Hitherto, the limitation associate with the TIG welding process is a low depth of penetration which reduces productivity. Activated tungsten inert gas welding (ATIG) is the best suitable option to overcome this problem and satisfy the sustainable welding requirement. Welding procedure has been developed for chromium manganese austenitic stainless steel during ATIG welding using a box behken design (BBD) to improve penetration depth and productivity. The activated flux using SiO2 and TiO2 flux indicates improvement in penetration 5.3 mm and 5.1 mm as compared to TIG welding. The ATIG welded test coupon has strength and hardness of 495 MPa and 195 HV when using SiO2 flux, and 487 MPa and 190 HV when using TiO2 flux, compared to 435 MPa and 165 HV for the TIG welded test coupon. ATIG welds have higher strength and hardness because of their finer grain size when compared to TIG welded test coupons.

Effect of grain refinement on sensitization of high manganese austenitic stainless steel

Effect of grain size on degree of sensitization (DOS) was been evaluated in Nickel free steel. Manganese and nitrogen contained alloy is a Ni free austenitic stainless steel (ASS) having type 202 grade. In the present investigation, the deformation of 202 grade analyzed using XRD and microstructural testing. Optical Microstructure of Ni free austenitic stainless steel (ASS) has been done for cold worked samples with thermally aged at 900 °C_6 Hrs. Ni free austenitic stainless steel (ASS) appears to be deformed more rapidly due to its higher stacking fault energy which gave results in rapid transformation from strain induced martensite to austenite in form of recrystallized grains, i.e., it concluded that as cold work percentage increases more rapidly recrystallization occurs. XRD results also indicate that more fraction of martensite formed as percentage of CW increases but as thermal ageing reverted those all martensite to austenite. Double Loop Electro-potentio Reactivation Method (DLEPR) test used for findings of degree of sensitization. So investigation gives the conclusion which suggest that with high deformation at higher temperature and duration gives very less degree of sensitization (DOS).

Corrosion and Cavitation Resistance of High-Strength Austenitic Nitrogen Stainless Steels in Seawater

Abstract—The corrosion and cavitation resistance of high-strength economically alloyed nitrogen-bearing chromium–nickel–manganese austenitic C10Cr19Mn10Ni6Mo2N and C09Cr19Mn10Ni6Mo2Cu2N stainless steels in seawater is compared experimentally with the properties of chromium–nickel C04Cr18Ni9 and C04Cr18Ni9N steels. The resistance to pitting corrosion is tested by a chemical method in a 100-g/L FeCl3 · 6H2O solution. The overall corrosion resistance is assessed by tests in synthetic seawater (3% NaCl). The cavitation resistance in seawater is tested by means of a high-intensity cavitation system based on a Hielscher Ultrasonic UIP 1000hd ultrasound unit in 3% aqueous NaCl solution (vibration frequency 20 kHz, power 1000 W, amplitude 25 μm) for 8–36 h. After cavitation treatment, the damage and change in microhardness at the sample surface is estimated, as well as the change in phase composition and mass of the samples in the tests. According to the tests, C10Cr19Mn10Ni6Mo2N and C09Cr19Mn10Ni6Mo2Cu2N steels are free of pits after exposure to seawater and iron-chloride solution. The overall corrosion rate is lower than for chromonickel Cr18Ni9 steel. Ultrasonic cavitation may lead not only to surface damage by erosion and intensification of local corrosion but also to change in the physical and mechanical properties on account of cold working and phase transformations. The resistance to ultrasonic cavitation in seawater is greater for C10Cr19Mn10Ni6Mo2N and C09Cr19Mn10Ni6Mo2Cu2N steels, containing thermally and mechanically stable austenite, than for chromonickel steels, especially C04Cr18Ni9, which is weaker and less stable. For example, after 36-h cavitational treatment in seawater, significant changes in state are seen in C04Cr18Ni9 and C04Cr18Ni9N steels: considerable damage (etching) and hardening of the surface and also the formation of a small quantity of martensite in C04Cr18Ni9 steel. For C10Cr19Mn10Ni6Mo2N and C09Cr19Mn10Ni6Mo2Cu2N steels, the tests indicate only slight change in state of the surface and hardening.

Tribo-corrosion study of nickel-free, high nitrogen and high manganese austenitic stainless steel

The electrochemical corrosion and tribo-corrosion behaviors of nickel-free high nitrogen (HN SS) and high manganese containing austenitic stainless steel were studied in simulated body fluids such as Ringer's and artificial saliva solutions (ASS) using tribo-meter attached with the potentiostat. Type 316L SS used as reference alloy for comparison. Open circuit potential (OCP) and potentiodynamic polarization techniques were used to examine the passivation and corrosion behavior of both the stainless steels under the applied loads of 5 and 10 N at room temperature and also compared with the static condition of corrosion. Pitting resistance of HN SS was found to be significantly higher over type 316L SS.

Attenuation capability of low activation-modified high manganese austenitic stainless steel for fusion reactor system

Low nickel-high manganese austenitic stainless steel alloys, SSMn9Ni and SSMn10Ni, were developed to use as a shielding material in fusion reactor system. A standard austenitic stainless steel SS316L was prepared and studied as a reference sample. The microstructure properties of the present stainless steel alloys were investigated using Schaeffler diagram, optical microscopy, and X-ray diffraction pattern. Mainly, an austenite phase was observed for the prepared stainless steel alloys. Additionally, a small ferrite phase was observed in SS316L and SSMn10Ni samples. The mechanical properties of the prepared alloys were studied using Vickers hardness and tensile tests at room temperature. The studied manganese stainless steel alloys showed higher hardness, yield strength, and ultimate tensile strength than SS316L. On the other hand, the manganese stainless steel elongation had relatively lower values than the standard SS316L. The removal cross section for both slow and total slow (primary and those slowed down in sample) neutrons were carried out using 241Am-Be neutron source. Gamma ray attenuation parameters were carried out for different gamma ray energy lines which emitted from 60Co and 232Th radioactive sources. The developed manganese stainless steel alloys had a higher total slow removal cross section than SS316L. While the slow neutron and gamma rays were nearly the same for all studied stainless steel alloys. From the obtained results, the developed manganese stainless steel alloys could be considered as candidate materials for fusion reactor system with low activation based on the short life time of manganese isotopes in a comparison with nickel.

An Overview of Welded Low Nickel Chrome-Manganese Austenitic and Ferritic Stainless Steel

Welding of Low Nickel Chrome-manganese Austenitic and ferritic Stainless Steel is an emerging area of research. Due to nickel price volatility, there was been increased interest in no-nickel or low-nickel economical grades of stainless steel. Chrome -manganese austenitic (“standard 200-series”) and ferritic stainless steel (“standard 300-series”) grades with well-defined technical properties have proved acceptable materials for specific applications for many years. This increase in the use and production of these low nickel grades is not currently matched by a proper level of user knowledge. So there is a risk that they may be used in unsuitable applications. It is very important to cultivate the method of fabrication like welding. This paper looks at the behavior of low nickel chrome-manganese and Ferritic austenitic stainless steel in terms of microstructure and sensitization effects.

Effect of austenite on mechanical properties in high manganese austenitic stainless steel with two phase of martensite and austenite

The effect of the austenite phase on mechanical properties of austenitic stainless steels was investigated using specimens with different volume fractions of retained and reversed austenite. Stainless steels with dual-phase coexisting martensite and austenite were successfully synthesized by deformation and reverse transformation treatment in the cold-rolled high manganese austenitic stainless steel and the ultrafine reverse austenite with less than 0.5 µm in size was formed by reverse transformation treatment in the temperature range of 500–750 °C for various times. With the increase of deformation degree, the volume fraction of retained austenite decreased, while that of the reversed austenite increased as the annealing time increased. From the results of the mechanical properties, it was obvious that as the volume fraction of retained and reversed austenite increased, hardness and strength rapidly decreased, while elongation increased. With regard to each austenite, reversed austenite indicated higher value of hardness and strength, while elongation suggested a lower value because of strengthening owing to grain refinement.

Mechanical Properties of High Manganese Austenitic Stainless Steel JK2LB for ITER Central Solenoid Jacket Material

A suite of advanced austenitic stainless steels are used for the ITER TF, CS and PF coil systems.These materials will be exposed to cyclic-stress at cryogenic temperature. Therefore, high manganese austenitic stainless steel JK2LB, which has high tensile strength, high ductility and high resistance to fatigue at 4K has been chosen for the CS conductor. The cryogenic temperature mechanical property data of this material are very important for the ITER magnet design. This study is focused on mechanical characteristics of JK2LB and its weld joint.

Dynamic recrystallization and precipitation in high manganese austenitic stainless steel during hot compression

Dynamic recrystallization and precipitation in a high manganese austenitic stainless steel were investigated by hot compression tests over temperatures of 950–1150°C at strain rates of 0.001 s−1-1 s−1. All the flow curves within the studied deformation regimes were typical of dynamic recrystallization. A window was constructed to determine the value of apparent activation energy as a function of strain rate and deformation temperature. The kinetics of dynamic recrystallization was analyzed using the Avrami kinetics equation. A range of apparent activation energy for hot deformation from 303 kJ/mol to 477 kJ/mol is obtained at different deformation regimes. Microscopic characterization confirms that under a certain deformation condition (medium Zener-Hollomon parameter (Z) values), dynamic recrystallization appears at first, but large particles can not inhibit the recrystallization. At low or high Z values, dynamic recrystallization may occur before dynamic precipitation and proceeds faster. In both cases, secondary phase precipitation is observed along prior austenite grain boundaries. Stress relaxation tests at the same deformation temperatures also confirm the possibility of dynamic precipitation. Unexpectedly, the Avrami’s exponent value increases with the increase of Z value. It is associated with the priority of dynamic recrystallization to dynamic precipitation at higher Z values.

Corrosion Behaviour of Chrome–Manganese Austenitic Stainless Steels and AISI 304 Stainless Steel in Chloride Environment

Electrochemical behaviour of chrome–manganese austenitic stainless steels (Cr–Mn ASS) and AISI 304 stainless steel (SS) is evaluated in various chloride (Cl−) concentrations (Cl− free to 20,000 ppm) to simulate rural, industrial and marine environment. Potentiodynamic polarization and electrochemical impedance spectroscopy has clearly shown that with increase in Cl− concentration, the corrosion rate of both Cr–Mn ASS and AISI 304 SS increases and polarization resistance decreases. Comparatively, Cr–Mn ASS is more affected by Cl− concentration than AISI 304 SS. This is attributed to relatively low Cr content and lack of Ni. The findings have been explained with the help of point defect model. However, in less aggressive environment of up to 100 ppm Cl− concentration, Cr–Mn ASS may be a candidate material as a cheaper substitute of AISI 304 SS. Ways of improving corrosion resistance of Cr–Mn ASS by alloying with various elements have also been discussed. It is argued that a dedicated effort is needed to improve corrosion resistance of Ni-free or low-Ni Cr–Mn ASS.

마르텐사이트와 오스테나이트의 2상 혼합조직을 갖는 고 Mn 오스테나이트 스테인리스강의 감쇠능

마르텐사이트와 오스테나이트의 2상 혼합조직을 갖는 고 Mn 오스테나이트 스테인리스강의 감쇠능

마르텐사이트와 오스테나이트의 2상 조직을 갖는 고 Mn 오스테나이트계 스테인리스강의 인장성질

The tensile properties of high manganese austenitic stainless steel with the two phase structures of deformation-induced martensite and reversed austenite were studied. Reversed austenite with an ultra-fine grain size of less than was obtained by reversion treatment. The two phases structures of deformation-induced martensite and reversed austenite were obtained by an annealing treatment in the range of for various times in 70% cold- rolled high-manganese austenitic stainless steel. The volume fraction of the reversed austenite increased rapidly with increases in the annealing temperature and time. In the stainless steel with the two phases of austenite and martensite, the strength decreased rapidly, while the elongation increased slowly and then rapidly increased with an increase in the volume fraction of the reversed austenite. Therefore, the strength and elongation were strongly controlled by the volume fraction of reversed austenite. A good combination of high strength and elongation could be obtained by the mixed structure of reversed austenite and deformation-induced martensite.

역변태 오스테나이트와 가공유기 마르텐사이트의 2상 혼합조직을 갖는 스테인리스강의 기계적 성질과 감쇠능

This study was carried out to investigate the relationship between mechanical properties and damping capacity in high manganese austenitic stainless steel with two phase mixed structure of reversed austenite and deformation induced martensite. Reversed austenite of ultra-fine grain size less than <TEX>$0.3{\mu}m$</TEX> was obtained by reversion treatment. Two phase structure of deformation induced martensite and reversed austenite was obtained by annealing treatment at range of <TEX>$500^{\circ}C{\sim}700^{\circ}C$</TEX> for various time in cold rolled high manganese austenite stainless steel. In stainless steel with two phase mixed structure of martensite and austenite, damping capacity decreased rapidly with the increasing hardness and strength. With the increasing elongation, damping capacity was increased rapidly and then, slowly increased.

냉간압연한 고 Mn 오스테나이트계 스테인리스강의 기계적 성질에 미치는 서브제로처리의 영향

The effect of subzero treatment on the mechanical properties of cold rolled high manganese austenitic stainless steel was investagated. <TEX>${\alpha}$</TEX>'-martensite was formed by cold rolling, and it was formed with surface relief and specific direction or crossing each other. The volume fraction of martensite increased by subzero treatment, and it was increased with longer time of subzero treatment and higher temperature of subzero treatment. The hardness and strength increased by subzero treatment, while the elongation decreased. With the increase of volume fraction of martensite, the hardness and strength was increased steeply with proportional relationship, elongation was decreased slowly. The results show that the hardness and strength was strongly controlled by the volume fraction of martensite, and the elongation was affected by transformation behavior of deformation induced martensite in the initial stage of deformation.

고 Mn 오스테나이트계 스테인리스강의 감쇠능에 미치는 역변태의 영향

This study was carried out to investigate the effect of reverse transformation on the damping capacity in high manganese austenitic stainless steel. <TEX>${\alpha}^{\prime}$</TEX>-martensite was formed with the specific direction and surface relief by deformation. Over 95% of the austenite phase was transformed to deformation-induced <TEX>${\alpha}^{\prime}$</TEX>-martensite by 70% cold rolling. Reverse transformation became rapid above an annealing temperature of <TEX>$550^{\circ}C$</TEX>, but there was no significant transformation above <TEX>$700^{\circ}C$</TEX>. In addition, with increasing annealing time at <TEX>$700^{\circ}C$</TEX>, reverse transformation was induced rapidly, but the transformation was almost completed at 10 min. Damping capacity was increased up to <TEX>$700^{\circ}C$</TEX>, and than unchanged with the increasing annealing temperature. Damping capacity increased steeply with an increasing reverse treatment time up to 10min, whereas there were no significant change with a treatment time of more than 10 min. Damping capacity increased with an increasing the reversed austenite and was strongly affected by reversed austenite.

고 Mn 오스테나이트계 스테인리스강의 기계적 성질에 미치는 가공온도의 영향

This study was carried out to investigate the effect of the deformation temperature in high manganese austenitic stainless steel. <TEX>${\alpha}$</TEX>'-martensite was formed with a specific direction by deformation. The volume fraction of the deformation induced martensite was increased by increasing the degree of deformation and decreasing the deformation temperature. With the increase in the deformation, the hardness and tensile strength were increased, while the elongation was rapidly decreased at the initial stage of the deformation, and then gradually decreased. The hardness and tensile strength were increased and the elongation was decreased with adecrease in the deformation temperature. The hardness and tensile strength were strongly controlled by the volume fraction of martensite, but the elongation was controlled by the transformation behavior of the deformation induced martensite.

고 Mn 오스테나이트계 스테인리스강의 기계적 성질에 미치는 역변태의 영향

This study was carried out to investigate the effect of reverse transformation on the mechanical properties in high manganese austenitic stainless steel. Over 95% of the austenite was transformed to deformation-induced martensite by 70% cold rolling. Reverse transformation became rapid above an annealing temperature of 550°C, but there was no significant transformation above 700°C. In addition, with an increasing annealing time at 700°C, reverse transformation was induced rapidly, but the transformation was almost completed at 10 min. There was a rapid decrese in strength and hardness with annealing at temperature above 550°C, while elongation increased rapidly above 600°C. At 700°C, hardness and strength decreased rapidly, and elongation increased steeply with an increasing reverse treatment time up to 10 min, whereas there were no significant change with a treatment time after 10 min. The reverse-transformed austenite showed an ultra-fine grain size less than 0.2 μm, which made it possible to strengthen the high manganese austenitic stainless steel. (Received February 22, 2012)