Microstructure and deformation behavior of a novel steel rebar: Effect of the heterogeneous microstructure of soft ferrite and Hard bainite

Journal of Materials Research and Technology

Falin Yang¹  Guowei Wang²  Dan Song³  Ningning Liang³  Huande Chen³  Han Ma⁴  Xiaolong Ma⁴  Jinghua Jiang⁵ 

[1] Nantong Research Institute of Materials Engineering, Nanjing University, Nantong, 226000, PR China;Suqian Research Institute, Hohai University, Suqian, 223800, PR China;College Of Mechanics And Materials, Hohai University, Nanjing, 211100, PR China;Jiangsu Shagang Group Co., Ltd, Zhangjiagang, 215600, PR China;School of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, PR China;

关键词: Alloyed steel rebar;    Dual-Phase steel;    Heterogeneous materials;    Mechanical performance;    Hetero-Deformation induced hardening;    EBSD characterization;   

DOI  :  

来源: DOAJ

【 摘 要 】

This study reports a detailed investigation of the deformation behavior and microstructural evolution of a novel ultra-low carbon Cr-Mo alloyed dual-phase steel rebar aimed for marine applications. The rebar matrix consists of the lamellar ferrite/bainite dual phases with the lamellar interfaces along the rolling direction. The soft ferrite phase is composed of larger grains with a low dislocation density, while the hard bainite phase is composed of finer grains with a much higher dislocation density. By comparing the strain hardening behavior from different sites at the rebar with varying ferrite and bainite volume fractions, it shows that the hetero-deformation induced (HDI) hardening is strong and dominates the overall work hardening behavior in the early stage of plastic deformation by prevailing over the conventional sum-up of contribution of each phase alone. In this stage, the plastic deformation of ferrite was constrained by the disproportionally-strained, neighboring bainite, creating the accumulation of geometrically necessary dislocations (GNDs) at the phase interface and the long-range HDI stress. The results also reinforce the understanding of deformation behavior of dual-phase steels, especially around the role of HDI stress and hardening.

【 授权许可】

Unknown