Multistage serrated flow behavior of a medium-manganese high-carbon steel
J. Chen1, Y. Zhang2, J.J. Wang1,3, C.M. Liu1,4, S.X. Zhao5
1 Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819, Liaoning, China 2 Shenyang Industrial Transformation Upgrading Promotion Center, Shenyang 110083, Liaoning, China 3 The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, Liaoning, China 4 School of Materials Science and Engineering, Northeastern University, Shenyang 110819, Liaoning, China 5 Central Research Institute, Baoshan Iron & Steel Co., Ltd., Shanghai 201999, China
Multistage serrated flow behavior of a medium-manganese high-carbon steel
J. Chen1, Y. Zhang2, J.J. Wang1,3, C.M. Liu1,4, S.X. Zhao5
1 Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819, Liaoning, China 2 Shenyang Industrial Transformation Upgrading Promotion Center, Shenyang 110083, Liaoning, China 3 The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, Liaoning, China 4 School of Materials Science and Engineering, Northeastern University, Shenyang 110819, Liaoning, China 5 Central Research Institute, Baoshan Iron & Steel Co., Ltd., Shanghai 201999, China
摘要 The deformation mechanisms and the flow stress behavior of a medium-manganese high-carbon steel during cold deformation at a strain rate of 10×5 s-1 were explored using a universal testing machine, an X-ray diffractometer, a field emission scanning electron microscope and a high-resolution transmission electron microscope. The results show that continuous step-up serrated flow behavior appears after the yielding point, and the true stress–strain curve is roughly divided into five stages based on distinctive densities and amplitudes of serration. The strengthening mechanisms of the experimental steel involve Cottrell atmosphere, twinning-induced plasticity (TWIP) efect and transformation-induced plasticity (TRIP) effect. TWIP effect is the dominant deformation mechanism, and deformation twins formed by TWIP effect comprise primary, secondary and nanotwins. Furthermore, TRIP effect arises in the local high-strain region. Carbon element plays a key role in the transformation of the deformation mechanism. A small amount of carbide precipitates around twin boundaries lead to the formation of local carbon-poor regions, and Md temperature and stacking fault energy of medium-manganese high-carbon steel are propitious to the occurrence of TRIP effect. In addition, the contributions of various deformation mechanisms to plasticity are calculated, and that of TWIP effect is the greatest.
Abstract:The deformation mechanisms and the flow stress behavior of a medium-manganese high-carbon steel during cold deformation at a strain rate of 10×5 s-1 were explored using a universal testing machine, an X-ray diffractometer, a field emission scanning electron microscope and a high-resolution transmission electron microscope. The results show that continuous step-up serrated flow behavior appears after the yielding point, and the true stress–strain curve is roughly divided into five stages based on distinctive densities and amplitudes of serration. The strengthening mechanisms of the experimental steel involve Cottrell atmosphere, twinning-induced plasticity (TWIP) efect and transformation-induced plasticity (TRIP) effect. TWIP effect is the dominant deformation mechanism, and deformation twins formed by TWIP effect comprise primary, secondary and nanotwins. Furthermore, TRIP effect arises in the local high-strain region. Carbon element plays a key role in the transformation of the deformation mechanism. A small amount of carbide precipitates around twin boundaries lead to the formation of local carbon-poor regions, and Md temperature and stacking fault energy of medium-manganese high-carbon steel are propitious to the occurrence of TRIP effect. In addition, the contributions of various deformation mechanisms to plasticity are calculated, and that of TWIP effect is the greatest.
J. Chen,Y. Zhang,J.J. Wang, et al. Multistage serrated flow behavior of a medium-manganese high-carbon steel[J]. Journal of Iron and Steel Research International, 2020, 27(9): 1064-1072.