AZ31B镁合金薄板挤压成形模拟分析  

Simulation analysis on thin sheet of magnesium alloy AZ31B in the extrusion process

作　　者：孙德河[1,2] 王丽薇[1,2] 解文科 

机构地区：[1]太原重工股份有限公司技术中心,山西太原030024 [2]太重(天津)滨海重型机械有限公司技术中心,天津300452

出　　处：《锻压技术》2016年第1期61-66,共6页Forging & Stamping Technology

基　　金：山西省科技创新项目(2013101012)

摘　　要：镁合金板材挤压工艺参数较难控制,挤压温度与挤压速度的合理匹配是挤压成功与否的关键。以宽度700 mm、厚度4 mm的AZ31B镁合金薄板为研究对象,基于Forge软件和Normalized Crockroft&Latham断裂准则对其挤压过程进行了模拟。结果表明,挤压初期,铸锭上、下部金属逐渐向心部流动,左、右两侧金属流动与挤压速度保持同向;中、后期,±45°方向金属发生分离,一部分与上、下部金属合流后继续向心部流动,另一部分与左、右侧金属合流后向薄板宽度方向扩展。随挤压行程增加,成形薄板加长,局部高温区域由薄板两侧向中间部分转移;初始挤压温度400℃时,若挤压速度超过1 mm·s^(-1),薄板局部高温区域温度较高,成形质量和使用性能不易保证。采用380~400℃的初始挤压温度,大约0.2 mm·s^(-1)的挤压速度,既可以显著降低设备成本,又利于保证薄板使用性能。It is difficult to control technological parameter of magnesium alloy in extrusion. The reasonable matching between extrusion temperature and speed is crucial to the success of extrusion forming. For magnesium alloy AZ31B sheet with width 700 mm and thickness 4 ram, the extrusion process was simulated by Forge software and fracture criterion of Normalized Crockroft ＆ Latham. The results show that, at early stage, the metal located in the upper and lower parts of ingot flows towards the core, meanwhile, the metal located in the left side and right side keeps flowing along the same direction as that of the extrusion speed ; at middle and later stage, the metal located in the direction of ＋ 45 o flows apart, one part merging with upper and lower metal keeps flowing towards the core, the other part merging with left side and right side metal extends along the width direction of thin sheet. With the increase of extrusion stroke, the length of formed thin sheet increases, and the local high temperature region transfers from both sides to the center section of thin sheet. When the initial extrusion temperature is 400℃, the extrusion speed exceeds 1 mm· s- 1, and the local high temperature region of thin sheet has a higher temperature. Furthermore, the forming quality and service performance are not easy to be guaranteed. The application of an initial extrusion temperature 380 -400 ℃ and an extrusion speed 0. 2 mm· s-1 will save the equipment costs significantly, and guarantee the service per- formance of thin sheet.

关 键 词：AZ31B镁合金 板材成形 挤压 模拟 

分 类 号：TG376[金属学及工艺—金属压力加工]