锻压技术

铸态Mn18Cr18N钢轧制热压缩实验分析

英文标题：Experimental analysis of rolling hot compression for ascast Mn18Cr18N steel

作者：刘洁张志红

单位：山西农业大学信息学院

分类号：TG335.8

出版年,卷(期):页码：2021,46(1):197-201

摘要：

针对铸态Mn18Cr18N电渣重熔钢进行了单道次直接轧制，其压下率分别为10%，30%，40%和50%，并借助电子背散射仪（EBSD）观察了微观组织，结果表明，单道次轧制时，随着压下率的增大，组织逐渐细化。在晶界周围发生再结晶，变形孪晶增多，促进再结晶形核发生。组织细化主要由动态再结晶机制和孪生机制起主导作用。分析了轧后板的拉伸力学性能，随着压下率的增大，屈服强度由690.16 MPa增加至743.24 MPa，抗拉强度由885.65 MPa增加至940.31 MPa，断后伸长率由39.73%增加至53.46%，断口微观形貌特征逐渐由韧性和脆性的混合型断裂向韧窝状韧性断裂转变。断口边部的第二相含量较少，而试样中心微孔洞内含有大量方形的第二相，导致形成了微裂纹，断裂先从中心部开始。

The as-cast Mn18Cr18N electroslag remelted steel was directly rolled in a single pass, and the reduction rates were 10%, 30%, 40% and 50%, respectively. The microstructure was observed by electron backscatter diffraction system (EBSD). The results show that the microstructure is gradually refined with the increasing of reduction rate in rolling with single pass. Recrystallization occurs around the grain boundary. The increasing of deformation twins promotes recrystallization nucleation. The structure refinement is dominated by the dynamic recrystallization mechanism and the twinning mechanism. The tensile mechanical properties of rolled sheet were analyzed. As the reduction rate increases, the yield strength increases from 690.16 MPa to 743.24 MPa, the tensile strength increases from 885.65 MPa to 940.31 MPa, and the elongation after fracture increases from 39.73% to 53.46%. The fracture morphology feature gradually changes from mixed fracture of toughness and brittleness to dimple toughness fracture. The content of the second phase at the edges of fracture is relatively small, while the microholes in the center of sample contain a large number of square second phases, and it causes the formation of microcracks, and the fracture starts from the center.

基金项目：

基金项目：面向新工科的《金属材料与热加工工艺》课程实践教学改革（晋教高[2018]6号）（J2018243）

作者简介：刘洁（1987-），女，硕士，讲师 E-mail：429842384@qq.com

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