超低碳贝氏体钢双相区回火过程中逆转变奥氏体的演变  

Evolution of reversed austenite in ultra-low carbon bainitic steel during intercritical tempering

作　　者：杨颖 潘诗良 许媛媛 王泽民 王占勇 Yang Ying;Pan Shiliang;Xu Yuanyuan;Wang Zemin;Wang Zhanyong(School of Materials Science and Engineering,Shanghai Institute of Technology,Shanghai 201418,China;Shanghai Pengtai Machinery Technology Co.,Ltd.,Shanghai 201406,China;Nantong High Entropy New Material Technology Co.,Ltd.,Nantong Jiangsu 226004,China)

机构地区：[1]上海应用技术大学材料科学与工程学院,上海201418 [2]上海朋泰机械科技有限公司,上海201406 [3]南通高熵新材料科技有限公司,江苏南通226004

出　　处：《金属热处理》2024年第3期182-189,共8页Heat Treatment of Metals

基　　金：国家重点研发计划(2017YFB0304501);上海科委项目(16090503600)。

摘　　要：将超低碳贝氏体钢淬火后在双相区回火不同时间,利用扫描电镜(SEM),电子背散射衍射(EBSD),透射电镜(TEM)和X射线应力仪研究逆转变奥氏体演变规律、Ni和Mn元素在基体及逆转变奥氏体中的分配。结果表明,淬火态的试样基体为板条贝氏体加少量残留奥氏体。随着回火时间的延长,基体中出现逆转变奥氏体,且含量先上升后降低,形貌由薄膜状演变成条块状。当回火时间为240 min时,基体中逆转变奥氏体最稳定且含量最高,约15.60%。逆转变奥氏体中Ni和Mn元素含量分别为15.23%和1.42%,远高于基体。当回火时间为1440 min时,逆转奥氏体含量降低至5.50%,部分逆转变奥氏体不稳定,转变为新生马氏体,其中Ni和Mn元素含量分别为12.58%和1.21%,略低于最稳定时逆转变奥氏体中Ni、Mn的含量。An ultra-low carbon bainitic steel was tempered in the dual-phase region for different time after quenching.The evolution of reversed austenite and the distribution of Ni and Mn elements in the matrix and in the reversed austenite were studied by means of scanning electron microscope(SEM),electron backscatter diffraction(EBSD),transmission electron microscope(TEM)and X-ray stress meter.The results show that the matrix of the quenched specimen is lath bainite with a small amount of retained austenite.With the extension of tempering time,reversed austenite appears in the matrix,and the content increases first and then decreases,and the morphology changes from film-like to strip-like.When the tempering time is up to 240 min,the reversed austenite in the matrix is the most stable and the content is the highest,about 15.6%.The content of Ni and Mn in the reversed austenite is 15.23%and 1.42%,respectively,which is much higher than that of the matrix.When the tempering time is 1440 min,the content of reversed austenite decreases to 5.50%,and the partially reversed austenite is unstable and transforms into new martensite.The contents of Ni and Mn are 12.58%and 1.21%,respectively,which is slightly lower than those in the most stable reversed austenite.

关 键 词：双相区回火 显微组织 板条贝氏体 逆转变奥氏体 新生马氏体 

分 类 号：TG142.1[一般工业技术—材料科学与工程]