
第42卷第11期 Vol. 42No. 11
爱压技术银
FORGING & STAMPING TECHNOLOGY
模具间隙对高强度钢热冲压过程的影响
邹伟12、蛋
张立强2,刘灿军2
2017年11月 Nov.2017
(1.湖南财经工业职业技术学院汽车工程系,湖南衡阳421002:2.中南林业科技大学机电工程学院,潮南长沙410004)摘要:利用DEFORM软件,建立了不等模具间度下高强度钢板热冲压的有限元模型,研究了模具间隙对22MnB5钢板热冲压成形中温度场以及马氏体转变的影响规律。数值模拟结果表明:模具间欧是影响板料温度变化的主要因素,板料的最大温差随着模具间院先增大后减小;模具间隙为0.95~1.00时,板料各部位的马氏体分布均匀,转变率高。在此基础上,进行了热冲压试验,测试了板料侧壁位置点和底部因角位置点的温度变化,并观察了板料成形后的微观组织,通过试验结果与数值模拟结果一致性对比,验证了数值模拟结果的可靠性与准确性。
关键词:高强度钢;模具间原;热冲压;数值模拟;温度场;马氏体转变 DOI; 10. 13330/j. issn. 1000-3940. 2017. 11. 007
中图分类号:TG76
文献标识码:A
文章编号:1000-3940(2017)11-0037-05
Influence of die clearance on hot stamping processfor high strength steel
Zou Wei'-, Zhang Liqiang, Liu Canjun?
(1. Department of Automotive Engineering, Hunan Financial & Industrial Vocational Technical College, Hengyang 421002, China; 2. College of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004, China) Abstract : A finite element model of the hot stamping for high strength steel was established under different die elearances by DEFORM sofiware, and the influences of die clearances on temperature field and martensite transformation of steel sheet 22MnB5 were studied. The mumerical simulation results indicate that the die cleanance is the main factor influencing the temperature change of part, and the maximum temperature difference of part increases with the increase of die clearance and then decreases. Furthermore, the martensite in every part of sheet is homogenously generated and has a higher transformation nate while the die clearance is 0. 95t 1. 00r, Therefore, the hot stamping experiment was executed based on the numerical simulation results, and the temperature changes in the position of sidewall and bottom corner of part were tested. Finally, the microstructures of sheet were observed, a gpod agreement between numerical simulation and exper imental results was verified, and the reliability and validity of numerical simulation results were verified.
Key words : high strength steel; die clearance; hot stamping; numerical simulation; temperature field; martensite transformation
随着环境污染、能源消耗等问题的加剧,对汽车减重和节能减排的要求越来越迫切,而在汽车零件制造上应用超高强度钢和高强度钢板是实现汽车减重和节能减排的有效途径之一[1-3]。
但高强钢在
常温下冲压易出现开裂、起皱等成形缺陷,而高强钢板热冲压技术能够改善上述存在的不良缺陷。
热
冲压高强钢成形件具有强度高、硬度高、刚度高、热成形中回弹小、成形零件精度高的优点,且抗碰
收稿日期:20170519;修订日期:20170805
基金项目:潮南省教育厅资助科研项目(13B145);湖南省大学生研究性学习和创新性实验计划项目(201510538010)
作者筒介:邹伟(1991-),男,颈土研究生 E-mail:429606865@ qy com
通讯作者:张立强(1978-),男,博士,副教投万方数据il:zlq2k1103@126.cm
撞性能相对原始高强钢板显著提高[4+}。热冲压成形技术是一种结合冲压成形与热处理成形的新型成形方法。近年来,越来越多的科研学者对高强度钢板热冲压技术进行了研究。李俊琛等[5]模拟分析了典型U形件高强度钢板的热冲压成形过程,建立了热、力耦合的有限元模型。刘文权等6]研究了高强度硼钢热冲压成形过程中板材内部细观损伤演化行为。刘春雨等]研究了一种轿车B柱上框加强板热成形件的模具冷却系统结构及工作原理。
本文以热冲压高强度钢22MnB5为研究对象,基于数值模拟方法,研究模具间隙对高强度钢板热冲压过程的影响,试图给出热成形钢板的温度场以及板条马氏体转变的影响规律。通过测试板料的侧壁位置点和底部圆角位置点的温度变化,并观察板料各部位的金相组织,来验证数值模拟结果的可靠