塑性强化材料矫直反弯特性研究  

Reverse Bending Research of Leveling on Plastic Hardening Material

作　　者：刘东冶 何安瑞[1] 王海滨 贺龙军 

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 [2]河北钢铁集团邯宝热轧厂,邯郸056000

出　　处：《机械工程学报》2015年第8期76-83,共8页Journal of Mechanical Engineering

基　　金：国家科技支撑计划(2012BAF09B04);北京青年英才计划(YETP0413);广西科技开发计划课题(2013AA01001)资助项目

摘　　要：为了深入研究塑性强化材料在平行辊式矫直过程中一次反弯与二次反弯特性的关系,根据工程弹塑性力学的基本原理,建立基于强化弹塑性材料辊式矫直弯曲力学模型。通过解析法描述两次反弯过程中的应力关系,给出辊式矫直过程中截面弯曲过程材料残余应力分布、弯矩比、加载应力变化过程。证明两次反弯过程中经历一次反弯后,二次反弯截面弯矩比与曲率比不再是原有简单M-C关系,而是与一次弯曲曲率比、二次弯曲曲率比与强化系数相关的函数。理论上证明原有弯曲理论不再完全适用于多次连续反弯矫直过程。解析结果表明,辊式矫直过程中经历二次反弯的材料截面弹性极限弯矩值下降,矫直弯曲减小,回弹比增大。同种材料考虑强化与不考虑强化矫直后残余应力均方差分别为71.2与65.6,回弹比均值分别为0.49和0.43。In order to further study the relevance between the first and the second reserve bending in the process of parallel roller level of plastic hardening material. Roller level bending mechanical model is established based on hardening elastic-plastic material in accordance with the fundamental of engineering elastic-plastic mechanics. The stress relevance of the two reserve bending processes is described by analytical method and discussed out the changing process of residual stress distribution, moment and loading stress with the section bending process of the roller level. With this model it is demonstrated that moment ratio and curvature ration is not simple “M-C” relation any longer, but function related to the first curvature ratio, the second curvature ratio and hardening factors. It is theoretically proved the original curvature theory can not apply to multi-reserve bending leveling processes. Analytical results show that during the second reserve bending process, there are decreased elastic limit bending moment and the bending moment in leveling process but increased spring-back ratio. Considered hardening of the same material residual stress mean square deviation are 71.2 and 65.6, average rebound ratio are 0.49 and 0.43.

关 键 词：塑性强化 辊式矫直 残余应力 弯矩比 曲率比 

分 类 号：TG333[金属学及工艺—金属压力加工]