两相区退火时间对Fe-0.16C-0.2Si-4.78Mn-0.24Mo中锰钢组织和力学性能的影响  

Effect of intercritical annealing time on microstructure and mechanical properties of Fe-0.16C-0.2Si-4.78Mn-0.24Mo medium manganese steel

作　　者：郑昊青 孟少博 任武彬 孙新军[2] Zheng Haoqing;Meng Shaobo;Ren Wubin;Sun Xinjun(State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,Pangang Group Research Institute Co.,Ltd.,Panzhihua Sichuan 617000,China;Research Institute of Structural Steels,Central Iron and Steel Research Institute Company Limited,Beijing 100081,China)

机构地区：[1]攀钢集团研究院有限公司钒钛资源综合利用国家重点实验室,四川攀枝花617000 [2]钢铁研究总院有限公司工程用钢研究院,北京100081

出　　处：《金属热处理》2024年第10期133-139,共7页Heat Treatment of Metals

摘　　要：采用扫描电镜、电子背散射衍射、X射线衍射、透射电镜、室温拉伸和0℃冲击试验等研究了两相区退火时间对Fe-0.16C-0.2Si-4.78Mn-0.24Mo中锰钢组织与力学性能的影响。结果表明:热轧态试验钢组织主要以马氏体为主,而经不同时间退火后的组织由马氏体和逆转变奥氏体组成;随着退火时间的增加,逆转变奥氏体含量线性增加,在退火30h后到达峰值,为12.74%,此时组织中除薄膜状奥氏体和条状奥氏体外,还出现大尺寸的块状奥氏体;试验钢的屈服强度和抗拉强度随退火时间的增加逐渐降低,这主要归因于逆转变奥氏体含量的增加以及位错密度的下降;0℃冲击吸收能量随退火时间的增加逐渐升高,伸长率先升高后降低,这主要归因于逆转变奥氏体的TRIP效应提高了冲击性能和塑性,但退火30h后奥氏体稳定性下降导致伸长率降低;经600℃退火30h后,试验钢具有最佳的TRIP效应。Effect of intercritical annealing time on microstructure and mechanical properties of Fe-0.16C-0.2Si-4.78Mn-0.24Mo medium manganese steel was studied by means of scanning electron microscope,electron backscatter diffraction,X-ray diffraction and transmission electron microscope,room temperature tensile test and impact test at O℃.The results show that the microstructure of the hot-rolled steel is mainly composed of martensite,while the microstructure after annealing for different time is composed of martensite and reverse austenite.With the increase of annealing time,the content of reverse austenite increases linearly,reaching a peak value of 12.74%after annealing for 30 h.At this time,in addition to film-like austenite and strip austenite,large sized blocky austenite also appears in the microstructure.The yield strength and tensile strength of the tested steel gradually decrease with the increase of annealing time,which are mainly attributed to the increase in reverse austenite content and the decrease in dislocation density.With the increase of annealing time,the impact absorbed energy at O℃gradually increases,and the elongation first increases and then decreases,which is due to the TRIP effect of reversing austenite improving the impact property and plasticity,but the stability of austenite decreases after annealing for 30 h,leading to a decrease in elongation.After annealing at 600℃for 30 h,the tested steel exhibits the best TRIP effect.

关 键 词：中锰钢 逆转变奥氏体 两相区退火 显微组织演变 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]