轧制工艺对D6A钢微观组织和力学性能的影响  

Effect of rolling process on microstructure and mechanical properties of D6A steel

作　　者：马梦晗 黄婷[1] 申勇峰[1] MA Menghan;HUANG Ting;SHEN Yongfeng(Key Laboratory for Anisotropy and Texture of Materials,Ministry of Education(Northeastern University),Shenyang 110819,China)

机构地区：[1]材料各向异性与织构教育部重点实验室(东北大学),沈阳110819

出　　处：《材料科学与工艺》2021年第1期23-29,共7页Materials Science and Technology

基　　金：国家重点研发计划项目(2016YFB0300600);国家自然科学基金资助项目(51574079)。

摘　　要：为了研究轧制工艺对D6A钢组织及力学性能的影响,分别制备了87%和93%压下量的D6A钢,并通过EBSD和拉伸性能测试进行了分析。结果表明,随轧制压下量由87%增加至93%,D6A钢中晶粒尺寸显著减小,由5μm减至1μm,小角度晶界含量则大幅增加,由55%增至80%。随轧制压下量的增加,D6A钢的抗拉强度及屈服强度均显著增加,其中抗拉强度由1175 MPa增加至1245 MPa,屈服强度则由1010 MPa增加至1195 MPa,而断后延伸率则有所降低,由19%降低至17%。同时,绘制了拉伸过程中加工硬化率变化曲线,分析表明,随着轧制压下量的增加,晶界及亚晶界强化提升了钢材的抗拉及屈服强度,而由于过于细小的晶粒和亚晶粒贮存位错的能力不足,使材料在变形时因缺乏加工硬化而过早发生颈缩导致其塑性降低。In order to study the effect of rolling process on the microstructure and mechanical properties of D6A steel,D6A steel with 87%and 93%rolling reduction were prepared in this study.The effect of rolling process on the microstructure and mechanical properties of D6A steel was analyzed by EBSD and tensile tests.The results show that,as the rolling reduction increased from 87%to 93%,the grain size of D6A steel significantly decreased from 5μm to 1μm,and the content of low angle grain boundary increased from 55%to 80%.With increasing the rolling reduction,the tensile strength,and the yield strength increased from 1175 MPa to 1245 MPa,and from 1010 MPa to 1195 MPa,respectively,whereas the elongation decreased from 19%to 17%.Meanwhile the work hardening rate curves of the two kinds of steel were plotted.An increase in the rolling reduction causes an increase in both the tensile and the yield strength of D6A steel due to the grain and sub-grain refinement,and a decrease in the tensile plasticity due to the insufficient storage capacity of the dislocations in small grain and sub-grain,thereby leading to the premature necking during the tensile process.

关 键 词：超大压下量 轧制 D6A钢 拉伸性能 加工硬化率 

分 类 号：TG14[金属学及工艺—金属材料]