scholarly journals Effect of the Deformation Degree on the Microstructure Evolution of an Austenite Reverted Transformation-Annealed Medium Manganese Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 887 ◽  
Author(s):  
Caiyi Liu ◽  
Yan Peng ◽  
Ling Kong ◽  
Yanqiang Wang
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Microstructure Evolution ◽  
Retained Austenite ◽  
Lath Martensite ◽  
Annealing Process ◽  
Reverse Transformation ◽  
Manganese Steel ◽  
Deformation Degree ◽  
Medium Manganese Steel

An Fe-0.15C-1.2Si-5Mn-0.09Nb-0.08V-0.07Mo (wt.%) medium manganese steel that was subjected to a novel austenite reverted transformation (ART) annealing process. This paper is based on the conventional ART annealing process, and a deformation and ART annealing process is proposed. The influence of the deformation degree on the microstructure and grain size of the medium manganese steel was determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron backscatter diffraction (EBSD) and X-ray diffraction (XRD). The results show that the deformation had a great effect on the microstructure evolution and grain size. The microstructure of the medium manganese steel after the deformation and ART annealing process was consistent with the theory of austenite reverse transformation, i.e., the martensite reverse transformation into austenite occurred during the deformation and ART annealing process. The final microstructure was a mixture of martensite and austenite. As the deformation degree increases, the martensite gradually refines, and carbides precipitate in the lath martensite. The retained austenite is gradually transformed from very large to small and is distributed between the martensite laths. The results show that when deformation occurs in the austenite region, a small deformation can obtain more retained austenite.

Microstructure and Mechanical Properties of Medium Manganese Steel Plate with High Strength and Toughness

2016 ◽  
Vol 879 ◽  
pp. 2293-2299
Author(s):  
Ying Zou ◽  
Yun Bo Xu ◽  
Zhi Ping Hu ◽  
Xiao Long Yang ◽  
Xiao Dong Tan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Retained Austenite ◽  
Annealing Temperature ◽  
Steel Plate ◽  
Volume Fraction ◽  
Manganese Steel ◽  
Uniaxial Tensile ◽  
Medium Manganese Steel ◽  
Strength And Toughness

An intercritical annealing process was applied to a medium manganese steel plate (Fe-0.01C-5.3Mn-1.53Si) after the thermo-mechanical controlled processing (TMCP) and ultrafast cooling (UFC). The microstructures were observed by scanning electron microscopy (SEM) equipped with electron backscatter diffraction (EBSD), electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM). The retained austenite was measured by XRD and mechanical properties were measured by uniaxial tensile and impact tests. The influence of different annealing temperature was compared and the relationship between microstructures and mechanical properties was investigated. Results showed that the microstructures of the medium manganese steel plate were characterized by ultrafine grained lath-like ferrite and retained austenite and the excellent mechanical properties could be obtained at the annealing temperature of 640°C for 5 h. The volume fraction of the retained austenite reached up to 21%, which could significantly increase the elongation compared with the traditional steel plate. The mechanical property results revealed that the steel possessed adequate ultimate tensile strength of 865MPa and excellent impact energy of 121J (-20°C). The outstanding combination of strength and toughness indicates that the steel has a bright application prospect.

Investigations on Microstructure Evolution and Deformation Behavior of Aged and Ultrafine Grained Al-Zn-Mg Alloy Subjected to Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 253-258
Author(s):  
Wei Ping Hu ◽  
Si Yuan Zhang ◽  
Xiao Yu He ◽  
Zhen Yang Liu ◽  
Rolf Berghammer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Microstructure Evolution ◽  
Deformation Behavior ◽  
Deformation Mechanisms ◽  
Mg Alloy ◽  
Ultrafine Grained

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.

Microstructure Evolution and Mechanical Properties of 67GPa•% Grade Medium Manganese Steel

2021 ◽  
Vol 1035 ◽  
pp. 404-409
Author(s):  
Zhe Rui Zhang ◽  
Ren Bo Song ◽  
Nai Peng Zhou ◽  
Wei Feng Huo
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Annealing Temperature ◽  
High Strength ◽  
Total Elongation ◽  
Manganese Steel ◽  
Experimental Steel ◽  
Medium Manganese Steel ◽  
Hot Rolled ◽  
Hot Rolled Steel

In this study, a new Fe-6Mn-4Al-0.4C high strength medium manganese hot rolled steel sheet was designed. The influence mechanism of the intercritical annealing (IA) temperature on microstructure evolution and mechanical properties of experimental steel were studied by SEM and XRD. The experimental steel was held for 30 minutes at 640°C, 680°C, 720°C, 760°C, 800°C, respectively. When the annealing temperature was 640°C, cementite particles precipitated between the austenite and ferrite phase boundary. As the annealing temperature increased, the cementite gradually dissolved and disappeared, the fraction of lamellar austenite increased significantly. When the annealing temperature is 800°C, the coarse equiaxed austenite and ferrite appeared. The yield strength (YS) decreased, the product of strength and elongation (PSE) and total elongation (TE) both increased first and then decreased, while the ultimate tensile strength (UTS) showed the opposite trend. The experimental steel exhibited excellent comprehensive mechanical properties after held at 760°C for 30 min. The UTS was 870 MPa, the YS was 703 MPa, and the TE was 77 %, the PSE was 67 GPa·%.

scholarly journals Microstructure-Tensile Properties Relationship and Austenite Stability of a Nb-Mo Micro-Alloyed Medium-Mn TRIP Steel

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 615 ◽  
Author(s):  
Chunquan Liu ◽  
Qichun Peng ◽  
Zhengliang Xue ◽  
Mingming Deng ◽  
Shijie Wang ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Trip Steel ◽  
Retained Austenite ◽  
Temperature Stability ◽  
Manganese Steel ◽  
Austenite Stability ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Medium Manganese Steel ◽  
Lüders Band

This study investigated the microstructure–tensile properties relationship and the retained austenite room temperature stability of a Nb and Mo micro-alloyed medium manganese transformation induced plasticity (TRIP) steel. A number of findings were obtained. Most importantly, the steel after being processed by quenching and tempering (Q & T) exhibited excellent tensile properties, i.e., the strength of 878–1373 MPa, the ductility of 18–40% Mo, and Nb microalloying served to control the fraction of retained austenite and to improve tensile strength by fine grain strengthening. Excellent tensile properties were attributable to the large amount of retained austenite which produced a discontinuous TRIP effect. This effect led to the production a large amount of martensite which relieved the stress concentration, contributing to the coordinated deformation between the phases and thus improving the deformability of the steel. Additionally, the differences in Mn and C contents led to varying degrees of austenite stability and the length of the Lüders band decreased as the inter critical annealing temperature increased. The micro-alloyed medium manganese steel experimented on our study showed considerable improvement in tensile properties in comparison with the 5Mn-0.1C medium manganese steel in previous studies.

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