温轧和临界退火制备超细晶异构双相钢的微观结构及力学性能  

Microstructure and mechanical properties of ultrafine grained heterostructured dual-phase steel prepared by warm rolling and intercritical annealing

作　　者：颜文超 高波 肖礼容 周浩 Yan Wenchao;Gao Bo;Xiao Lirong;Zhou Hao(Nano and Heterogeneous Materials Center,School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing Jiangsu 210094,China)

机构地区：[1]南京理工大学材料科学与工程学院纳米异构材料中心,江苏南京210094

出　　处：《金属热处理》2024年第7期54-63,共10页Heat Treatment of Metals

基　　金：国家自然科学基金(52201124)。

摘　　要：通过制备超细晶异构双相钢大幅度提升了低碳钢的综合力学性能。首先对低碳双相组织进行300℃温轧充分细化初始结构,然后通过740℃临界退火处理得到具有高马氏体含量(77%,体积分数)的超细晶异构双相组织,其中铁素体和马氏体的平均晶粒尺寸分别为0.78和0.39μm。该超细晶异构双相钢具有优异的综合力学性能,屈服和抗拉强度分别为1.26和1.75 GPa,同时可以保持6.2%的均匀延伸率。在拉伸变形过程中超细晶异构双相钢中铁素体和马氏体之间的力学性能差异产生了显著的异变诱导硬化,可以提高整体的加工硬化率,从而提高低碳钢的强度-塑性匹配。Comprehensive mechanical properties of the low-carbon steel were greatly improved by producing the ultra-fine grained heterostructured dual-phase(UFG-HSDP)structure.First,the initial structure of the low carbon dual-phase structure is refined by warm rolling at 300℃,and then the ultra-fine grained heterostructured dual-phase steel with high martensite content(volume fraction of 77%)is obtained by intercritical annealing at 740℃.The average grain size of ferrite and martensite is 0.78 and 0.39μm,respectively.The UFG-HSDP steel shows excellent comprehensive mechanical properties,with yield and tensile strengths of 1.26 and 1.75 GPa,respectively,while maintaining a uniform elongation of 6.2%.The mechanical incompatibility between ferrite and martensite in the UFG-HSDP steel during tensile deformation results in significant hetero-deformation induced hardening,which enhances the total strain hardening rate and thus improves the strength-ductility match of low-carbon steel.

关 键 词：低碳钢 异构材料 力学性能 应变硬化 异变诱导应力 

分 类 号：TG142.1[一般工业技术—材料科学与工程]