应力状态对模具分区冷却热成形S-rail硬度分布的影响  

Influence of stress state on the hardness distribution of S-rail in tailored die quenching process

作　　者：胡平[1,2] 张金女[1] 申国哲[1] 林发财 刘立忠[1] 

机构地区：[1]大连理工大学汽车工程学院,辽宁大连116024 [2]大连理工大学工业装备结构分析国家重点实验室,辽宁大连116024

出　　处：《吉林大学学报（工学版）》2016年第2期500-504,共5页Journal of Jilin University:Engineering and Technology Edition

基　　金：'973'国家重大基础研究发展计划项目(2010CB832700);中央高校基本科研业务费专项项目(DUT11ZD202);高等学校博士学科点专项科研基金项目(20100041120017)

摘　　要：利用S-rail模具,以汽车用超高强度钢BR22MnB5为研究对象,结合模具分区冷却热成形工艺研究了模具温度及成形件应力状态对其最终硬度的影响。研究显示:随着模具温度升高,成形件的硬度减小;当模具热区和冷区的温度分别为400℃和室温(20℃)时,相应区域的硬度分别为300HV和460HV,热、冷区之间的硬度出现明显的梯度变化;板料在热成形过程中发生变形,其内圆角处受压应力,抑制马氏体生成,而外圆角处受拉应力,马氏体更易生成,所以外圆角硬度值大于其内圆角硬度值。The influences of tool temperature and stress state of stamped part on its hardness distribution are investigated in tailed die quenching process of vehicle-use ultra high strength steel BR22MnB5.The results show that the hardness of the stamped part decreases with the increase in tool temperature.When the tool is heated up to 400°C,apart with hardness of 300 HV in the hot region and 460 HV in the cold region is produced.Furthermore,during the stamping,the inner fillet of the stamped part is compressed while the outer fillet of the blank experiences tensile stress.So the hardness of the outer fillet is higher than that of the inner fillet in the stamped part.

关 键 词：材料合成与加工工艺 BR22MnB5 模具分区冷却热成形 应力状态 硬度 

分 类 号：TG306[金属学及工艺—金属压力加工]