低碳低合金无碳化物贝氏体钢热处理工艺及组织性能研究  

Research on Heat Treatment Process and Microstructure and Properties of Low-carbon Low-alloy Carbide-free Bainite Steel

作　　者：苏震 邸洪双[1] 张天宇 柯浩鹏 SU Zhen;DI Hongshuang;ZHANG Tianyu;KE Haopeng(State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《热加工工艺》2024年第17期140-145,共6页Hot Working Technology

基　　金：国家自然科学基金资助项目(51775102);国家重点研发计划(2018YFB1308704)。

摘　　要：开展了实验钢在Ms点以上及以下保温不同时间的等温淬火实验,结合高分辨膨胀仪、电子背散射衍射(EBSD)、X射线衍射(XRD)等其它实验手段,探究了引入一次马氏体对贝氏体相变动力学的影响,以及不同等温时间转变后微观组织和力学性能之间的关系。结果表明,在Ms点以下等温阶段引入的一次马氏体显著地加速了贝氏体相变动力学,并且提高了实验钢的屈服强度和伸长率。这是因为引入的一次马氏体为贝氏体提供了更多的形核界面,并且获得了由回火马氏体、二次马氏体、贝氏体和残余奥氏体组成的多相组织,其中较多数量的残余奥氏体因TRIP效应从而使实验钢的塑性提高。实验钢在300℃等温2 h后,其抗拉强度、屈服强度分别为1475、986 MPa,伸长率高达18.5%。The isothermal quenching experiment of experimental steel above Ms point was carried.The effect of the introduction of primary marstenite on the dynamics of bestenite phase transition was explored using other experimental methods such as high-resolution dilander,electron backscattering diffraction(EBSD)and X-ray diffraction(XRD),as well as the relationship between the microstructure and mechanical properties after different isothermal time transformations were explored.The results show that the introduction of primary martensite at the isothermal stage below the Ms point significantly accelerates the kinetics of bainite transformation and improves the yield strength and elongation of the experimental steel.This is because the introduced primary martensite provides more nucleation interfaces for the growth of bainite,and obtains a polyphase structure of tempered martensite,secondary martensite,bainite and retained austenite.Among them,a larger amount of retained austenite increase the plasticity of the experimental steel due to the TRIP effect.Finally,after the experimental steel is isothermally held at 300℃for 2 h,its tensile strength and yield strength are respectively 1475 MPa and 986MPa,and the elongation is up to 18.5%.

关 键 词：无碳化物贝氏体钢 热处理工艺 微观组织 力学性能 

分 类 号：TG161[金属学及工艺—热处理]