Deformation mode and strain path dependence of martensite phase transformation in a medium manganese TRIP steel

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:711

Article

Wu, Wei¹  Wang, Yu-Wei¹  Makrygiannis, Panagiotis¹  Zhu, Feng¹  Thomas, Grant A.²  Hector, Louis G., Jr.³  Hu, Xiaohua⁴  Sun, Xin⁵  Ren, Yang⁶ 

[1] AK Steel Corp, AK Steel Res & Innovat, Dearborn, MI 48120 USA

[2] AK Steel Corp, AK Steel Res & Innovat, Middletown, OH 45005 USA

[3] Gen Motors Corp, GM Global Tech Ctr, 30470 Harley Earl Blvd, Warren, MI 48092 USA

[4] Pacific Northwest Natl Lab, POB 999, Richland, WA 99352 USA

[5] Oak Ridge Natl Lab, Oak Ridge, TN 37930 USA

[6] Argonne Natl Lab, Xray Sci Div, Argonne, IL 60439 USA

关键词: Deformation modes;    Martensite phase transformation;    Non-linear strain path;   

DOI  :  10.1016/j.msea.2017.11.008

来源: Elsevier

【 摘 要 】

The martensite phase transformation dependence upon deformation modes and strain paths in a medium manganese (10 wt%) TRIP steel stamped into a T-shape panel was quantified through combination of 3D digital image correlation and synchrotron X-ray diffraction. The T-shape emulates a portion of a common anti-intrusion component. The stamping speed was kept intentionally slow (1 mm/s) so as to avoid excessive heat generation. The steel, which belongs to the third generation advanced high strength steel (3GAHSS) family, was chosen for two reasons: (1) it is two-phase, i.e. austenite and ferrite, with martensite resulting from deformation-induced phase transformation; (2) the 66 vot% initial retained austenite volume fraction (RAVF) enabled a thorough examination of the martensite phase transformation at large deformation levels without exhaustion. Strain fields were coupled with measured RAVF values of small specimens extracted from specific locations on a formed T-shape panel. This enabled an exploration of the effects of linear, bilinear, and non-linear strain paths as well as deformation modes such as tension, plane strain, biaxial tension, and equibiaxial tension. Results suggest a significant martensite phase transformation dependence on deformation mode and strain path in the absence of fracture and when martensite phase transformation is unaffected by heat generated during forming. In general, the uniaxial and biaxial tension deformation modes facilitate the martensite phase transformation, while the smallest amount of martensite phase transformation occurs under plane strain. Some discussion as to further application of the experimental methods detailed in this study to other 3GAHSS and the effects of fracture on martensite phase transformation is provided.

【 授权许可】

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