模具热导率对热冲压成形工艺影响的数值研究

发布时间：2018-10-14 16:11

【摘要】：为了评价模具材料的导热性能对热冲压成形工艺的影响,选择优质H13钢和自主开发的HDLM热冲压专用模具材料进行对比分析,采用LF457型激光导热仪对模具材料的导热性能进行评价,使用光学显微镜、扫描电镜和透射电镜对其组织进行观察。同时,建立了盒形件热冲压成形及模内淬火过程的数值仿真模型,研究了模具热导率对成形件冷却行为、组织演变以及模具温度的影响规律。研究表明,在热冲压模具服役温度200~400℃内,HDLM模具钢的热导率高于40 W/(m·℃),约为H13钢的1.5倍;在热冲压保压淬火过程中,模具材料的热导率对热冲压成形件的冷却行为起重要作用;当模具材料为HDLM钢时,仅需约10 s就能使盒形件关键部位的组织完全转变为马氏体,相比于H13钢,其保压冷却时间缩短了近41%,保压冷却效率提升了约80%,有效地加快了热冲压生产节拍和提高了生产效率,并且模具温度的均匀性也有较大改善,最高温度不超过330℃,有利于延长模具的使用寿命。
[Abstract]:In order to evaluate the influence of thermal conductivity of die materials on hot stamping process, high quality H13 steel and HDLM hot stamping die materials developed by ourselves were selected for comparative analysis. The thermal conductivity of mould materials was evaluated by LF457 laser thermal conductivity instrument, and the microstructure was observed by optical microscope, scanning electron microscope and transmission electron microscope. At the same time, the numerical simulation model of hot stamping forming and quenching process of box parts is established, and the influence of die thermal conductivity on cooling behavior, microstructure evolution and die temperature of forming parts is studied. The results show that the thermal conductivity of HDLM die steel is more than 40 W / (m 鈩，

本文编号：2270963