第42卷第4期 Vol.42No.4
理论与实验研究
假压技术
FORGING & STAMPING TECHNOLOGY
刘志森"2，林建平1,2，王雪松"2，舒常乐1,2
（1.同济大学上海市地面交通工具空气动力与热环境模拟重点实验室，上海201804：
2.同济大学机械与能源工程学院，上海201804）
2017年4月 Apr.2017
摘要：接触热阻是影响热冲压过程中热能传导的一个重要因素，面零件不同区域的温差则直接影响热冲压的回弹，因此，获得准确的接触热阻数值对提高热冲压回弹仿真的精度具有重要意义。基于稳态法设计了22MnB5板件与Cr7V模具钢接触热阻的测量实验，推导出接触热阻的计算公式；并按照实验方法搭建了实验平台，获得了不同压强下两者的接触热阻值；最后拟合了接触热阻与压强的关系方程。将关系方程带人某B柱的热冲压回弹仿真中，与原始仿真对比发现，改进后的仿真结果与实际实验值较为接近，证明获得准确的接触热阻与压强的关系方程可提高硼钢板热冲压回弹的仿真精度，
关键词：接触热阻；硼钢板：热冲压；回弹仿真；稳态法 DOI: 10. 13330/j. issn. 1000-3940. 2017. 04. 029
中图分类号：TG306
文献标识码：A
文章编号：1000-3940（2017）04-0165-05
Experimental investigation oncontactthermalresistancebetween boronsteel and
dieanditsapplicationtospringbacksimulation Liu Zhimiao'-2, Lin Jianpingl-2, Wang Xuesong'-2, Shu Changle.2
(1. Shanghai Key Laboratory of Vehicle Aerodynamics and Vehicle Thermal Management Systems , Tongji University,
Shanghai 201804, China; 2. School of Mechanical and Energy Engineering College, Tongji University, Shanghai 201804, China) Abstract : The contact thermal resistance is an important influence of thermal propagation in the hot stamping process, However, the temper-ature difference among various regions of parts affects the hot stamping springhack directly. So it is of great significance to obtain aceurale contact thermal resistance for improving springhack simulation accuracy in the bot stamping process. The measurement experiment on contact thermal resistance between boron sheet 22MnB5 and die steel Cr7V was designed by the steady-state method, and the calculation fomula of contact thermal resistance was deduced. According to this measurement method, a test platform was built, and values of contact thermal re-sistance under different pressures were obtained respectively. Finally , a relational equation between contact thermal resistance and pressure was fitted. Furthemore, the relational equation was input into a B pillar hot stamping springhack simulation, and the improved simulation re sults were closer to the experimental one by comparing with the original simulation results, Thus, it is indicated that obtaining accurate relational equation between contact themal resistance and presure can improve simulation accuracy of springhack in the hot stanping for boron steel. Key words: contact thermal resistance; boron steel; hot stamping ; springback simulation; steady-state method
热冲压工艺是汽车轻量化的关键技术，22MnB5
硼钢板是主要的热冲压材料之一。热冲压过程中板料与模具之间的接触热阻会影响模具、板料的冷却速度，进而影响零件各区域的温度。研究表明[2]，界面压强会影响接触热阻的大小，而零件的
收稿日期：20161205；修订日期：20170215 基金项目：国家自然科学基金资助项目（51375346）
作者简介：刘志森（1992-），女，硕士研究生 E-mail: liuzm0524@ 163. com
通讯作者：林建平（1958-），男，博士，教授
E-mail: jplin58@ tongji. edu. cn 万方数据
复杂性又导致各区域的压强不相等，故零件各处的接触热阻不同。传统热冲压仿真中零件各处的接触热阻通常设置为统一值，与实际情况并不相符，导致仿真与实验结果有较大差异。因此，有必要研究不同界面压强下硼钢板与模具间的接触热阻值，以提高热冲压回弹仿真精度。
首先，为获得板件与模具间准确的接触热阻，必须进行有效的实验研究。目前实验研究中，稳态法在界面接触热阻测量中最为常用[3-4]。刘冬欢等[5]自主搭建了一套基于稳态法的高温接触热阻实验平台，针对三维编织C/C复合材料与高温合金