异步轧制对AZ31镁合金静态再结晶及晶粒细化的影响  

Effect of differential speed rolling on static recrystallization and grain refinement of AZ31 magnesium alloy

作　　者：孟强[1] 蔡庆伍[1] 江海涛[1] 胡水平[1] 李振[1] 

机构地区：[1]北京科技大学高效轧制国家工程研究中心,北京100083

出　　处：《北京科技大学学报》2011年第1期47-52,共6页Journal of University of Science and Technology Beijing

基　　金：'十一五'国家科技支撑计划资助项目(No.2006BAE04B02)

摘　　要：研究了AZ31镁合金薄板在异步轧制过程中,异速比、压下率及退火工艺对其退火晶粒尺寸的影响.结果表明:适当提高轧制异速比和道次压下率能够显著细化晶粒,但是异速比过高时,轧辊与轧件会产生相对滑动,细化晶粒效果降低,其中异速比为1.3时,细化晶粒效果最佳;剪切作用使镁合金中孪晶数量及分布均匀程度提高,位错缠结被'切碎',畸变能得以更均匀地分布于变形体内,是异步轧制具有良好晶粒细化效果的主要原因;此外,合理的异步轧制工艺还能缩短镁合金板带所需的中间退火和成品退火时间.The effect of speed ratio, rolling reduction ratio and annealing on the recrystallization grain size of AZ31 magnesium alloy sheets was studied under the condition of differential speed roiling process. It is shown that the grains can be significantly refined by increasing the speed ratio and reduction ratio. But when the speed ratio is too high, sliding occurs between the rolls and sheets, lower- ing grain refinement. A speed ratio of 1.3 provides the best grain refinement. The major reason that differential speed rolling leads to a better grain refinement is that shearing deformation in differential speed rolling can increase the number and uniformity of twins and cut up dislocation cells or walls, the distortion energy more evenly distributes in the magnesium alloy. In addition, a reasonable differential speed rolling process also reduces the middle and final annealing time.

关 键 词：镁合金 轧制 再结晶 退火 晶粒细化 

分 类 号：TG166.4[金属学及工艺—热处理]