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

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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Unraveling the significant role of retained austenite on the dry sliding wear behavior of medium manganese steel

Wear ◽

10.1016/j.wear.2021.203745 ◽

2021 ◽

pp. 203745

Author(s):

Xincheng Yan ◽

Jun Hu ◽

Hao Yu ◽

Chenchong Wang ◽

Wei Xu

Keyword(s):

Significant Role ◽

Retained Austenite ◽

Sliding Wear ◽

Wear Behavior ◽

Manganese Steel ◽

Dry Sliding Wear ◽

Dry Sliding ◽

Medium Manganese Steel

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Austenite stability and its effect on the toughness of a high strength ultra-low carbon medium manganese steel plate

Materials Science and Engineering A ◽

10.1016/j.msea.2016.07.104 ◽

2016 ◽

Vol 675 ◽

pp. 153-163 ◽

Cited By ~ 51

Author(s):

Y. Zou ◽

Y.B. Xu ◽

Z.P. Hu ◽

X.L. Gu ◽

F. Peng ◽

...

Keyword(s):

Steel Plate ◽

High Strength ◽

Manganese Steel ◽

Low Carbon ◽

Austenite Stability ◽

Medium Manganese Steel

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Effect of Aluminum and Vanadium on Retained Austenite Stability and Work Hardening in Silicon Free TRIP Steel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.835.347 ◽

2020 ◽

Vol 835 ◽

pp. 347-352

Author(s):

Ahmed El-Sherbiny ◽

Mohamed Kamal El-Fawkhry ◽

Ahmed Y. Shash ◽

Tarek M. El-Hossainy ◽

Ayman Mohamed Fathy ◽

...

Keyword(s):

Strain Hardening ◽

Trip Steel ◽

Retained Austenite ◽

X Ray Diffraction ◽

Alloying Element ◽

Etching Technique ◽

Complete Replacement ◽

Austenite Stability ◽

Retained Austenite Stability ◽

Strong Candidate

Despite that the conventional CSiMn TRIP steel has a promissing mechanical attributes, it has a limitations on the galvanizability of such grades of steel due to Silicon. Thus, aluminum as a strong candidate for substituting silicon has been introduced in this study accompanied by vanadium as a microalloying element. Microstructure of the studied steel was observed by using OM, and SEM. X-ray diffraction analysis, and tent-etching technique carried out on the studied steel to identify the fractions of the retained Austenite after thermal mechanical process, as well as its morphology. In addition, the mechanical properties in term of strength, ductility, strain hardening, and the rate of strain hardening were studied to define the influenced parameters throughout this alteration. The results refer to the possibility of complete replacement of silicon in TRIP steel with aluminum at the presence of vanadium as a micro alloying element.

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Ultrafine also can be ductile: On the essence of Lüders band elongation in ultrafine-grained medium manganese steel

Materials Science and Engineering A ◽

10.1016/j.msea.2018.07.052 ◽

2018 ◽

Vol 733 ◽

pp. 220-223 ◽

Cited By ~ 8

Author(s):

Y. Zhang ◽

H. Ding

Keyword(s):

Manganese Steel ◽

Ultrafine Grained ◽

Medium Manganese Steel ◽

Lüders Band

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

Metals ◽

10.3390/met10070887 ◽

2020 ◽

Vol 10 (7) ◽

pp. 887 ◽

Cited By ~ 1

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.

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In Situ Neutron Diffraction Analysis of Phase Transformation Kinetics in TRIP Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.502.339 ◽

2005 ◽

Vol 502 ◽

pp. 339-344 ◽

Cited By ~ 7

Author(s):

Jozef Zrník ◽

O. Muránsky ◽

Petr Lukáš ◽

Petr Šittner ◽

Z. Nový

Keyword(s):

Neutron Diffraction ◽

Trip Steel ◽

Retained Austenite ◽

Volume Fraction ◽

Internal Stresses ◽

Austenite Transformation ◽

Austenite Stability ◽

Retained Austenite Stability ◽

In Situ Neutron Diffraction

The precise characterization of the multiphase microstructure of low alloyed TRIP steels is of great importance for the interpretation and optimisation of their mechanical properties. In-situ neutron diffraction experiment was employed for monitoring of conditioned austenite transformation to ferrite, and also for retained austenite stability evaluation during subsequent mechanical loading. The progress in austenite decomposition to ferrite is monitored at different transformation temperatures. The relevant information on the course of transformation is extracted from neutron diffraction spectra. The integrated intensities of austenite and ferrite neutron diffraction profiles over the time of transformation are then assumed as a measure of the volume fractions of both phases in dependence on transformation temperature. Useful information was also obtained on retained austenite stability in TRIP steel during mechanical testing. The in-situ neutron diffraction experiments were conducted at two different diffractometers to assess the reliability of neutron diffraction technique in monitoring the transformation of retained austenite during room temperature tensile test. In both experiments the neutron investigation was focused on the volume fraction quantification of retained austenite as well as on internal stresses rising in structure phases due to retained austenite transformation.

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Tempering Effects on the Stability of Retained Austenite and Mechanical Properties in a Medium Manganese Steel

ISIJ International ◽

10.2355/isijinternational.52.868 ◽

2012 ◽

Vol 52 (5) ◽

pp. 868-873 ◽

Cited By ~ 38

Author(s):

Hai Feng Xu ◽

Jie Zhao ◽

Wen Quan Cao ◽

Jie Shi ◽

Cun Yun Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Retained Austenite ◽

Manganese Steel ◽

Medium Manganese Steel ◽

The Stability

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The significance of microstructural evolution on governing impact toughness of Fe-0.2C-6Mn-3Al medium-Mn TRIP steel studied by a novel heat treatment

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-7877 ◽

2021 ◽

Vol 112 (4) ◽

pp. 271-279

Author(s):

Zhichao Li ◽

Xinjing Li ◽

Yanjie Mou ◽

Zhihui Cai ◽

Devesh Misra ◽

...

Keyword(s):

Impact Toughness ◽

Trip Steel ◽

Volume Fraction ◽

High Impact ◽

Manganese Steel ◽

X Ray Diffraction ◽

Tempering Temperature ◽

Medium Manganese Steel ◽

Fundamental Understanding ◽

The Impact

Abstract We address here the continuing challenge and scientific gap in obtaining high impact toughness in medium-Mn steels. While addressing the challenge, the objective of the study described here is to obtain a fundamental understanding via critical experimental analysis of the reasons underlying high impact toughness that was successfully obtained in Fe-0.2C-6Mn-3Al medium-Mn TRIP steel. Electron microscopy and X-ray diffraction studies clearly underscored the absence of the TRIP effect in Fe-0.2C-6Mn-3Al medium manganese steel during impact and the volume fraction of austenite played a determining role in governing impact toughness. The highest impact toughness of 213.6 J · cm–2 was obtained when the steel was subjected to an intercritical hardening temperature of 700 °C and low tempering temperature of 200 °C. The presence of martensite in the microstructure reduced the impact toughness on quenching from 750 – 850 °C.

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Effect of Annealing Temperature on Austenite Stability of a δ-TRIP Steel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.818.82 ◽

2019 ◽

Vol 818 ◽

pp. 82-86

Author(s):

Xin Xu ◽

Ren Dong Liu ◽

Bao Yu Xu ◽

Hong Liang Yi ◽

Guo Dong Wang

Keyword(s):

Mechanical Properties ◽

Trip Steel ◽

Retained Austenite ◽

Annealing Temperature ◽

Volume Fraction ◽

X Ray Diffraction ◽

X Ray ◽

Austenite Stability ◽

Poor Stability ◽

Better Than

In this work, a novel type of δ-TRIP steel was designed, and the content and stability of retained austenite in δ-TRIP specimens under different annealing processes were detected and studied, respectively. The volume fraction of austenite was determined by X-ray diffraction (XRD). The microstructure and mechanical properties were analyzed systematically. The results show that a complex microstructure composed of three phases (ferrite, bainite and retained austenite) was obtained in the δ-TRIP steel. With the increasing of annealing temperature, both retained austenite and bainite content in the specimen increased, while the carbon content in retained austenite decreased, leading to a poor stability for retained austenite. Both tensile and yield strength improved with the increasing of annealing temperature, while the elongation reduced. The feature of retained austenite led to an excellent combination of ductility and strength, which was better than traditional TRIP steel.

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