铸态镁合金大压下轧制对组织和边裂的影响  

Effects of the Heavy Reduction Rolling on the Microstructure and Edge Crack of Casted Magnesium Alloys

作　　者：丁云鹏[1] 乐启炽[1] 张志强[1] 崔建忠[1] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2014年第3期379-382,387,共5页Journal of Northeastern University(Natural Science)

基　　金：国家重点基础研究计划项目(2013CB632203);国家"十二五"科技支撑计划项目(2011BAE22B03;2011BAE22B04);辽宁省高等学校优秀人才支持计划项目(LJQ2012023);辽宁省自然科学基金资助项目(201202072)

摘　　要：主要研究了道次压下率和轧制道次数对AZ31B扁锭坯大压下轧制所制备板材边裂以及微观组织的影响.轧制工艺为350℃下两道次或四道次大压下轧制.金相观察、边裂统计和XRD织构分析表明:当总压下率达到37%时,轧板开始出现边裂;并且裂纹深度随着压下率的增大而增加.随着压下率的增加,孪晶明显增多.当总压下率达到54%时,大部分区域已完成再结晶;进一步增大压下率,组织中出现变形局域化现象;当总压下率为82%,轧制道次增多时,边裂出现一定程度减弱,同时基面织构分布由双峰变为单峰.The effects of the reduction per pass and the number of rolling passes on edge cracks and microstructure were investigated when the magnesium AZ31B sheets were processed by hot rolling with large reduction from slabs. The sheets were subjected to two-pass or four-pass rolling at 350 ℃. The specimens were examined by optical microscopy, edge crack statistic and X-ray diffraction. The results indicated that edge cracks appeared when the reduction rates reached 37% , and the edge crack depth increased with the increase of reduction rate. The twins also increased with the increase of the reduction rate. When total reduction rate reached 54% , most of part of the microstructure was completed. When the reduction rate increased further, shear bands appeared. For the rolling with 82% total reduction, when the rolling pass increased, the level of edge cracks decreased to some extent. Meanwhile, the basal texture changes from two basal poles to only one.

关 键 词：镁合金 大压下 轧制 边裂 微观组织 

分 类 号：TG335[金属学及工艺—金属压力加工]