Effect laws and mechanisms of different temperatures on isothermal tensile fracture morphologies of high-strength boron steel
来源期刊：中南大学学报(英文版)2015年第4期
论文作者：LIU Jia-ning SONG Yan-li LU Jue GUO Wei
文章页码：1191 - 1202
Key words：high-strength boron steel; fracture morphology; isothermal tensile test
Abstract: The fracture behaviour and morphologies of high-strength boron steel were investigated at different temperatures at a constant strain rate of 0.1 s-1 based on isothermal tensile tests. Fracture mechanisms were also analyzed based on the relationship between microstructure transformation and continuous cooling transformation (CCT) curves. It is found that 1) fractures of the investigated steel at high temperatures are dimple fractures; 2) the deformation of high-strength boron steel at high temperatures accelerates diffusion transformations; thus, to obtain full martensite, a higher cooling rate is needed; and 3) the investigated steel has the best plasticity when the deformation temperature is 750 °C.
LIU Jia-ning(刘佳宁)1, SONG Yan-li(宋燕利)2, 3, LU Jue(路珏)1, GUO Wei(郭巍)2, 3
(1. School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China;
2. Hubei Key Laboratory of Advanced Technology of Automotive Parts
(Wuhan University of Technology), Wuhan 430070, China;
3. School of Automotive Engineering, Wuhan University of Technology, Wuhan 430070, China)
Abstract:The fracture behaviour and morphologies of high-strength boron steel were investigated at different temperatures at a constant strain rate of 0.1 s-1 based on isothermal tensile tests. Fracture mechanisms were also analyzed based on the relationship between microstructure transformation and continuous cooling transformation (CCT) curves. It is found that 1) fractures of the investigated steel at high temperatures are dimple fractures; 2) the deformation of high-strength boron steel at high temperatures accelerates diffusion transformations; thus, to obtain full martensite, a higher cooling rate is needed; and 3) the investigated steel has the best plasticity when the deformation temperature is 750 °C.
Key words:high-strength boron steel; fracture morphology; isothermal tensile test
