Manganese Steel Research Articles

Effect of quenching–partitioning process on corrosion behavior and mechanism of medium manganese steel

Effect of quenching–partitioning process on corrosion behavior and mechanism of medium manganese steel

Anisotropy of acoustic properties in thin-sheet rolled low-carbon manganese steel

Thin-sheet rolled low-carbon manganese steel 09G2S with a thickness of 0,8 mm which has strong property anisotropy due to texture and residual stresses, was experimentally studied using SH-wave with horizontal polarization and zero-order symmetric Lamb wave mode. The velocities of elastic wave propagation along the sheet were analyzed as their direction and polarization varied relative to the rolling direction in the range of angles from 0 to 180 degrees. The excitation and reception of normal waves in the sheet were carried out by piezoelectric transducers with dry point contact, providing tangential force application. The results of the research on the anisotropy of acoustic properties, X-ray structural analysis of residual stresses and inverse pole figures, and metallographic studies were obtained.

Corrosion behavior of high manganese steel by iron-oxidizing bacteria in wastewater at the bottom of liquefied natural gas storage tanks

High manganese steel is a new generation of material for the fabrication of liquefied natural gas (LNG) storage tanks. The corrosion behavior of high manganese steel induced by iron-oxidizing bacteria (IOB) living in wastewater from LNG tanks bottom was investigated. The results revealed that IOB can induce a generation of a dense and thick biotransformation film on the steel. Interestingly, the biotransformation film could be able to reduce the corrosion rate of high manganese steel by 71% and alleviate the formation of corrosion pits. A corrosion inhibition mechanism is postulated, elucidating the protective role of the iron-manganese oxide composite biofilm.

The Effect of Heating Rate on the Microstructure Evolution and Hardness of Heterogeneous Manganese Steel.

The use of a rapid heating method to achieve heterogeneity of Mn in medium-manganese steel and improve its comprehensive performance has been widely studied and these techniques have been widely applied. However, the heating rate (from α to γ) has not received sufficient attention with respect to its microstructure-evolution mechanism. In this study, the effect of heating rate on the microstructure evolution and hardness of heterogeneous medium-manganese steel was investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and DICTRA simulation. The results showed that the Mn distribution was heterogeneous in the initial microstructure of pearlite due to strong partitioning of Mn between ferrite and cementite. At low heating rates (<10 °C/s), the heterogeneity of Mn distribution was diminished to some extent due to the long-distance diffusion of Mn in high-temperature austenite. Contrastingly, at high heating rates, the initial heterogeneity of the Mn element could be largely preserved due to insufficient diffusion of Mn, which resulted in more ghost pearlite (GP: pearlite-like microstructure with film martensite/RA). Moreover, the high heating rate not only refines the prior austenite grain but also increases the total RA content, which is mainly composed of additional film RA. As the heating rate increases, the hardness gradually increases from 628.1 HV to 663.3 HV, due to grain refinement and increased dislocation density. Dynamic simulations have also demonstrated a strong correlation between this interesting microstructure and the non-equilibrium diffusion of Mn.

Retained austenite in medium manganese steel with dissimilar morphology and composition

The microstructure and mechanical properties of medium manganese steel with a composition of 0.2C-5Mn-0.5Si-1.5Al (wt.%) were investigated, employing a two-stage heat treatment process. The microstructure following pretreatment comprised pearlite, martensite, and ferrite. Subsequent intercritical annealing resulted in the formation of retained austenite with varying morphology and composition. The filmy retained austenite transformed from pearlite exhibited a higher Mn content compared to the blocky retained austenite transformed from martensite, while also displaying a slower growth rate. Moreover, the filmy retained austenite exhibited superior thermal and mechanical stability. Tensile tests showed that the test steels not only obtained high strength (&gt;1000 MPa) and high elongation (&gt;30%), but the stress-strain curves also showed continuous yielding behaviour and a more reasonable ratio of tensile strength to yield strength.

Stepwise warm rolling for synergistic strength and ductility enhancement in heterolamellar medium-Mn steel

Medium manganese steel represents a promising third-generation advanced high-strength steel. However, achieving excellent plasticity in high-yield-strength medium manganese steel remains challenging, particularly with lower alloying element contents. In this study, we employed an innovative stepwise warm rolling process on 5Mn medium manganese steel, developing a heterolamellar microstructure along the rolling direction. The resulting steel exhibited a yield strength exceeding 1.5 GPa while maintaining a uniform elongation of approximately 29%. The high yield strength is attributed to fine lamellar grains with high dislocation density, while the excellent uniform elongation is due to the synergistic effect of multiple plastic deformation mechanisms, which promoted prolonged strain hardening and delayed the onset of necking. These mechanisms include hetero-deformation induced (HDI) hardening generated during the early deformation of the heterolamellar structure, transformation induced plasticity (TRIP) effect-induced work hardening, and delamination cracking that alleviates interface strain concentration and delays material failure. Collectively, these mechanisms enabled the material to achieve an exceptionally high product of yield strength and uniform elongation of 45 GPa·%. This work provides new insights into the design of high-strength, ductile medium manganese steels, advancing the application of high-performance medium manganese steels.

Hardfacing of GX40CrNiSi25-20 cast stainless steel with an austenitic manganese steel electrode

Abstract To enhance the wear and corrosion resistance of engineering components, various surface modification techniques have been devised. Among these, arc welding processes employing specialized electrodes offer relatively straightforward methods with low production costs for hardfacing applications. This paper focuses on the hardfacing process using pulsed current arc welding to reinforce cast austenitic steel structural components, aiming to prolong their lifespan. Typically, hardfacing coatings utilize Fe, Ni, and Co-based alloys. Among these, Fe-based alloys, such as manganese austenitic alloys employed in our experiments, are favored for their robust mechanical work hardening capacity, resulting in significant hardness enhancements (from 186–219 HV5 in the as-deposited layer to 468–492 HV5 after mechanical work hardening) under intense wear and impact conditions. The innovation of the hardfacing process developed in this study lies in utilizing a universal TIG source adapted for manual welding with a covered electrode in pulsed current mode. This hardfacing technique can be applied to both worn components in operation and new ones before being put into service, thereby ensuring long-term durability and reducing maintenance costs.

Corrosion Resistance Comparison of High Manganese Steel in 0.01mol/L NaHSO3 Solution and 3.5wt.% NaCl Solution

Corrosion Resistance Comparison of High Manganese Steel in 0.01mol/L NaHSO3 Solution and 3.5wt.% NaCl Solution

Understanding low-temperature microstructure and mechanical properties of a newly designed ultra-low carbon medium manganese steel

This study examines the relationship between microstructure and low-temperature mechanical properties of newly designed medium manganese steel with ultra-low carbon, low-Ni content. The microstructural features crucial for impact toughness were identified. The study indicated that post-annealing at 650 °C for 30 min endowed the steel with superior low-temperature mechanical properties, namely tensile strength of 914 MPa, total elongation of 37.2 %, and impact energy of 187 J at −60 °C. With longer intercritical annealing durations, reverted austenite transitioned from a film-like to a blocky morphology, with an increase in both volume fraction and size, accompanied by a substantial decrease in stability. High-stability reverted austenite contributed to sustained work hardening by facilitating a continuous Transformation-Induced Plasticity (TRIP) effect during steel deformation, thereby significantly enhancing the low temperature tensile properties of the steel. Furthermore, enhanced stability of reverted austenite was identified as the pivotal microstructural factor influencing impact toughness.

Effect of Pulsed Helium Ion and Helium Plasma Flows on Austenitic Chromium–Manganese Steel Preirradiated with Deuterium

Effect of Pulsed Helium Ion and Helium Plasma Flows on Austenitic Chromium–Manganese Steel Preirradiated with Deuterium

Preparation and properties of ZTA/alloyed high manganese steel composites

In the long-term use of high manganese steels, it is not desirable to achieve wear resistance by austenite deformation strengthening alone. The wear resistance of high manganese steel is much lower than that of ordinary wear-resistant steel under medium and low stress conditions. Improving the instability of wear resistance caused by defects in high manganese steels is an important problem to be solved in current industrial production. In this study, a new type of high manganese alloy with high hardness and high wear resistance was prepared by multi-alloying with Cr-W-Mo elements on the basis of 20Mn1.2C. ZTA ceramic particles reinforced high manganese steel composites were prepared by selecting high manganese steel materials with excellent mechanical properties as the metal matrix of ceramic reinforced metal matrix composites. The Cr-W-Mo multi-alloyed high manganese alloys are mainly composed of a mixed austenite and ferrite matrix, M3C-type cementite and M6C-type carbides. The Cr2W6Mo6 sample has the best overall mechanical properties. Its hardness reached 49.8 HRC, which is 1.20 times higher than that of the Cr2 sample. The mass loss was 0.2571 g, which is 79.92% of the Cr16 sample (0.3217 g). The ZTA ceramic particles were well composited with the alloyed high manganese steel matrix, and the thickness of the interfacial layer was 20-30 μm, with the formation of Mn2AlO4 and (Fe, Mn)2SiO4, and (Al, Cr)2O3 in the interfacial layer. The best abrasion resistance was obtained at a ZTA content of 40 vol.%. The mass loss was 0.1669 g, which is 51.88% of the Cr16 material (0.3217 g).

The effect of manganese and carbon on the mechanical properties of the welded layer of the bucket teeth of the Hadfield steel excavator

The paper investigates the effect of the surfacing composition’s chemical structure (the manganese and carbon concentrations’ ratio) on the mechanical properties of the surfacing layer on Hadfield steel for increasing the durability of the products made from it, namely the excavator bucket’s teeth. Two criteria, namely the impact toughness and wear resistance of the coating, were chosen as optimization parameters. The assessment of the impact strength of the deposited coating was carried out on the Sharpie samples on the pendulum copra, and the wear test was carried out according to the Brinly-Haworth scheme in the conditions of samples’ abrasion with quartz sand. Wear resistance of Hadfield steel, containing 1.1% C and 13% Mn, was taken as a unit of wear resistance in these experiments. To determine the optimal coating modes, the active experiment with the application of mathematical planning methods was conducted. The obtained response surfaces and graphs of equal output lines make it possible to establish the level of studied factors’ influence on the optimization parameter. In order to analyze the influence of given factors on the optimization criteria, scatter plots with histograms were constructed, which make it possible to determine the rational values ​​of the selected optimization criteria graphically - impact toughness and wear resistance of the coating

Strengthening mechanisms in vanadium-microalloyed medium-Mn steels

In this work, the impact of adding vanadium, ranging from 0 to 2 wt%, on the microstructure and mechanical properties of as-cast medium manganese steel was explored. A dual phase microstructure consisting of martensite and retained austenite was observed in the 0 V, 0.05 V and 0.8 V conditions. The 2 V condition contained retained austenite, lath martensite, and δ-ferrite bands. The retained austenite fraction and prior austenite grain size initially increased at lean vanadium concentrations but significantly dropped at the highest vanadium concentration. The element distribution in the constituent phases was investigated in detail. Mn, C and Si partitioning to austenite was observed in the 0 V, 0.05 V and 0.8 V conditions. V and C segregation to the grain boundaries and significant grain refinement were evident in the 2 V condition. The findings also revealed that increasing the vanadium content led to an increase in the hardness of the steel. This assessment was validated by tensile testing, which showed an improvement in yield and tensile strength of the steel with increasing vanadium content, and were supported by reconstruction of the parent austenite grains employing martensitic structures. Finally, the influence of different strengthening mechanisms on the yield strength of as-cast, microalloyed medium-manganese steels was also discussed in terms of simulated stacking fault energy, as well as the quantitative contributions from solid solution, grain boundary, and precipitation strengthening mechanisms.

Initiation of the Shape Memory Effect by Fast Neutron Irradiation

The band sample of austenitic steel 0.3C–13Cr–10Mn–3Si–1V was cold deformed to a shape of circular arc with a deflection of 3 mm and then irradiated by fast neutrons with a fluence of 6×1019 cm–2 in the vertical wet channel of the IVV-2M reactor at a temperature of 80 °C. This material belongs to the class of the stainless manganese austenitic steels with the shape memory effect (SME). The neutron irradiation was initially supposed to lower the SME upon the further heating in comparison with the reference sample. But instead, the SME appeared immediately under irradiation showing a decrease in the deflection of about 21 %. Check experiments confirmed that the lower limit of the SME in this material is 120 °C with its absence at 80 °C. This allows us to assert that the observed effect is the result of the neutron irradiation.

Experimental investigation on effect of cooling rate on carbide precipitation during solidification of high manganese steel

In order to elucidate the effect of cooling rate on the carbide formation during the solidification process of high manganese steel Mn13, the solidification process is artificially divided into two stages, namely the liquid-solid phase transition stage and solid-state cooling stage. The final Mn13 samples with different cooling rates are used to the analysis of solidification structure and carbides by high-temperature confocal microscopy (HTCLSM), optical microscopy (OM), electron backscatter diffraction (EBSD), and scanning electron microscopy (SEM). The result shows that the change of cooling rate at the liquid-solid phase transition stage has a great influence on the solidification structure and carbide precipitation. At this stage, with the increase of cooling rate from 0.2 °C/s to 5.0 °C/s, the dendrite structure is obviously refined, and the secondary dendrite arm spacing and cooling rate are satisfied with the relationship: λΠ=54.14×v−0.33. Also, the average grain size in the Mn13 sample decreases from 549 μm to 346 μm, and the aspect ratio of gains in the Mn13 sample increases from 1.7 to 2.0. Moreover, the distribution of carbide in the interdendritic regions and grain boundaries increases, and the morphology of carbide at the grain boundary change from block to dendrite. But it seems that the change of cooling rate from 1 °C/s to 5.0 °C/s at the solid-state cooling stage has a slight effect on the secondary dendrite arm spacing, the average size and aspect ratio of the grain structure and the amount and morphology of carbide precipitation at the grain boundary.

Current-manipulated martensite transformation to enhance strength-ductility synergy in a medium Mn steel

In order to quantify the thermal and athermal effects during pulse current assisted deformation, the deformation behavior of medium manganese steel was studied using forced air cooling. At room temperature, the ultimate tensile strength of medium manganese steel is 1350 MPa and the total elongation is 47.3 %. However, in the pulsed current assisted deformation under forced air cooling, its strength and ductility are synergistically improved, with the ultimate tensile strength increased to 1380 MPa and the total elongation increased to 57 %. Athermal effects can delay deformation-induced martensite transformation by reducing austenite dislocation density and reducing stress concentration at austenite-ferrite phase boundaries, resulting in better strength and ductility in the pulsed tensile sample with forced air cooling. While the thermal effect increases the strain energy required for deformation-induced martensite transformation, resulting in a decrease in martensitic content and a decrease in accumulated dislocation density. Therefore, compared with the sample with forced air cooling, the ultimate tensile strength of the pulse tensile sample without forced air cooling is reduced.

Microstructure Evolution and Tensile Properties of Medium Manganese Steel Heat Treated by Two-Step Annealing

In this paper, the nucleation and growth of austenite are controlled through a two-step annealing process to achieve multi-scale distribution and content increase of retained austenite in low manganese series medium-Mn steel. Combining SEM, EBSD, AES, and other experimental equipment, the evolution rules of the microstructure, properties, and element distribution behavior of the test steel during the annealing process are studied. Compared with one-step annealing, the two-step annealing significantly broadens the size distribution range of retained austenite. In the first step, after annealing at a higher intercritical temperature (760 °C), the ferrite and the M/A island are obtained, completing the initial partition of Mn and the refinement of microstructures. During the second step of annealing (720 °C), the primary Mn-rich martensite region provides higher nucleation driving force and finer dispersed nucleation sites, promoting the nucleation and growth of reverse transformation austenite. At the same time, the metastable-retained austenite formed after the first step of annealing continues to grow through interface movement. Furthermore, a high proportion (23.4%) of retained austenite with multi-scale distribution is formed in the final microstructure, and the product of strength and elongation increased from 21.8 GPa·% by the one-step annealing process to 30.1 GPa·%.

Effects of carbon content and heat treatment on wear-resistance and impact properties of novel cast steels with bainitic and martensitic structure

Abstract The traditional material for caterpillar boards is mainly Hadfield steel. The wear resistance of the Hadfield steel cannot be fully exerted due to insufficient work hardening during the operation of the caterpillar board. The effects of carbon content and heat treatment on the wear-resistant and impact properties of a novel caterpillar board cast steels with bainitic and martensitic structures have been investigated. The microstructural observation of worn surface topography was performed by scanning an electronic microscope, and the impact toughness was carried out by an impact tester, in a bid to improve the wear-resistant properties and its impact toughness. The results demonstrate that the hardness and wear-resistant properties of cast steels increase with the increase of carbon content, whereas the impact properties reduce because the brittle phases, such as the carbide precipitation and the martensite, are more. The heat treatment temperature of steels can change the relative ratio of bainitic and martensitic structures, thus affecting the wear-resistant properties of the steels. By controlling the carbon content and heat treatment processing of the steels, the optimal combination of toughness and wear-resistant properties can be achieved. The wear mechanism of dual-phase cast steel was analyzed through wear resistance tests, and it also shows that dual-phase cast steel with bainitic and martensitic structures had better wear-resistance properties compared to the Hadfield steel at low-impact wear conditions.

Microstructure and properties of in situ TiCP/Mn18Cr2 architecture composites

In situ TiC ceramic particle-reinforced steel matrix composites, typically produced via liquid metal infiltration of unstructured preforms, often demonstrate issues with composite areas being prone to fracture. To address this problem, particles with an average diameter of 3 mm were constructed and used to fabricate preforms. Using the in situ self-generation method, the composites were then synthesised with liquid Mn18Cr2. To control the degree of in situ spontaneous reaction, moderator alloy powders at concentrations of 20, 30, 40 and 50 wt.% were utilised. The results reveal that the TiC particle size in the composites gradually decreases as the moderator concentration in the preform increases, reducing from 1.31 to 0.92 μm. The microhardness and elastic modulus at the composite interfaces are intermediate between those of the TiC ceramic particles and the high manganese steel matrix. The inclusion of millimetre-scale architecture enhances the tensile strength of the composites, with tensile strength gradually increasing as the moderator content decreases. This study offers a comprehensive understanding of how moderator content influences the microstructure and mechanical properties of TiC-reinforced Mn18Cr2 composites, providing valuable insights for the development of high-performance structural materials.

Effects of temperature on the microstructural evolution and mechanical properties of copper − bearing medium manganese steel during tempering

This work introduced the effects of higher tempering temperatures on the microstructural evolution of Cu − bearing medium Mn steel. After quenching steel at 860 °C for 1 h, it was tempered at 600, 640, and 670 °C for 2 h. The results indicated that the low − temperature impact toughness initially increased and then decreased, while the yield strength consistently decreased with increasing temperature. At a tempering temperature of 640 °C, the steel exhibited a relatively high content of reversed austenite and demonstrated the best low − temperature toughness and plasticity. The low − temperature toughness and plasticity of the steel significantly diminished, when the temperature exceeded 640 °C. This is because the degree of alloying element enrichment in the reversed austenite is reduced, accompanied by an increase in dislocation density and the formation of twins. These reversed austenites exhibit a diminished ability to hinder crack nucleation and propagation. The yield strength decreased with increasing temperature, primarily due to the coarsening of the Cu particles, which reduces their precipitation strengthening effect. This study advances the development of high − strength tough medium − manganese steels.