退火-回火和回火-退火工艺对冷轧10Mn钢显微组织及力学性能的影响  

Effects of Annealing-tempering and Tempering-annealing Processes on Microstructure and Mechanical Properties of Cold-rolled 10Mn

作　　者：白韶斌 盛剑 李大赵[2] 陆海涛 陈永安 赵震宇 邢佳 BAI Shaobin;SHENG Jian;LI Dazhao;LU Haitao;CHEN Yongan;ZHAO Zhenyu;XING Jia(School of Aerospace Engineering,North University of China,Taiyuan 030051,China;School of Materials Science and Engineering,North University of China,Taiyuan 030051,China;School of Mechanical Engineering,North University of China,Taiyuan 030051,China;School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030051,China)

机构地区：[1]中北大学航空宇航学院,太原030051 [2]中北大学材料科学与工程学院,太原030051 [3]中北大学机械工程学院,太原030051 [4]太原科技大学材料科学与工程学院,太原030051

出　　处：《精密成形工程》2024年第11期82-90,共9页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(52205402,52375392,52071300);山西省基础研究计划青年项目(202203021212318,20210302124044);冲击环境材料技术重点实验室基金(6142902240502)。

摘　　要：目的研究退火-回火和回火-退火工艺对冷轧Fe-10.2Mn-2.2Al-0.41C-0.6V(质量分数)中锰钢显微组织和力学性能的影响,明晰上述2种工艺对奥氏体体积分数、晶粒尺寸及稳定性的影响规律,以及显微组织与力学性能的关联机制。方法在退火温度(600℃)、退火时间(30 min)和回火温度(550℃)、回火时间(30 min)一致的情况下,调整退火和回火工艺顺序,分析退火-回火和回火-退火工艺下组织与性能共通性及差异性。结果2种工艺对试验钢的奥氏体体积分数、晶粒尺寸及稳定性影响不大;变形前后的奥氏体转换率分别为88%(退火-回火试样)和86%(回火-退火试样),即奥氏体在变形阶段通过TRIP(Transformation-induced Plasticity)效应对2种试验钢力学性能的贡献无显著区别。退火-回火试样具有1320 MPa屈服强度、1435 MPa抗拉强度以及4.1%断后伸长率;回火-退火试样的屈服强度为1200 MPa、抗拉强度为1360 MPa、断后伸长率为6.6%。除了奥氏体的TRIP效应外,退火-回火试样中预先存在的马氏体是其较高抗拉强度的决定性因素,而回火-退火试样中的大量高角度晶界是其具有较好塑性的主要原因。此外,两试样的屈服强度差异主要与织构强化有关。结论退火-回火工艺有利于中锰钢强度的提高,而回火-退火工艺有利于中锰钢塑性的提升。The work aims to study the effects of anneal-tempering and tempering-annealing processes on the microstructure and mechanical properties of cold-rolled Fe-10.2Mn-2.2Al-0.41C-0.6V(wt%)medium Mn steel,so as to further reveal the ef-fect of the above processes on austenite volume fractions,grain sizes,and stability,as well as the correlation between micro-structure and mechanical properties.The variations of microstructure and mechanical properties in the steel with the sequential change of annealing(600,30 min)and tempering(550,30 min)processes were analyzed.The results showed that the s℃℃e-quential change had few effects on the austenite volume fraction,grain size and stability.The austenite transformation rates be-fore and after straining were evaluated to be 88%(annealed-tempered sample)and 86%(tempered-annealed sample),respectively.Namely,there was no significant difference about the contribution of TRIP effects on mechanical properties of the two studied steels.The yield strength,tensile strength,and total elongation of the annealed-tempered sample were 1320 MPa,1435 MPa,and 4.1%,respectively.The tempered-annealed sample exhibited a yield strength of 1200 MPa,tensile strength of 1360 MPa,and total elongation of 6.6%.In addition to the TRIP effect of austenite,the pre-existing martensite in the annealed-tempered sample played an essential role in its high tensile strength,while a large fraction of high-angle grain boundaries in the tem-pered-annealed sample contributed to the good ductility.Besides,the difference of yield strength between the two samples was closely related to the texture strengthening.Based on this study,it is concluded that the annealing-tempering and temper-ing-annealing processes are favorable to enhance the strength and plasticity of medium Mn steels,respectively.

关 键 词：中锰钢 κ-碳化物 奥氏体 马氏体转变 力学性能 强化机制 

分 类 号：TG142.1[一般工业技术—材料科学与工程]