汽车保险杠热冲压成形及坯料形状设计  

Hot stamping and blank shape design for vehicle bumper

作　　者：桂中祥[1] 张宜生[1] 李洪庆[1] 马鸣图[2] 葛锐[3] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074 [2]中国汽车工程研究院有限公司,重庆400039 [3]武汉钢铁(集团)公司,湖北武汉430083

出　　处：《锻压技术》2013年第3期19-23,共5页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51275185)

摘　　要：以某型号汽车的保险杠为对象,设计了全尺寸的热冲压成形模具;结合夹持和定位要求,对坯料形状进行了优化设计,通过工艺实验验证模具及板料设计的可靠性,并检验了热成形零件的微观组织及力学性能。结果表明:采用形状优化的板坯,在机械手输送过程中,其位置稳定性大大提高;金相分析显示热成形保险杠获得了完全马氏体组织,抗拉强度达到1550MPa,洛氏硬度为47.5HRC,且各测试点硬度十分均匀,伸长率可达6%;在保证板料临界冷却速率的前提下,提高模具温度有助于降低成形力和稳定淬火温度。The full-scaled hot stamping dies were designed for an automotive bumper, with the well-designed blank shape incorporated into clamping and positioning, experiments were conducted to verify the reliability of the die and sheet metal blank design, as well as the tests for microstructure and mechanical properties of the hot-stamped part. The results show that position stability of the blank is greatly improved during the robotic transport process after shape optimization. Metallographic analysis demonstrates that a fully martensitic microstructure is obtained in the hot-formed bumper, the tensile strength is about 1550 MPa, Rockwell hardness is 47.5 HRC, and the hardness of each test point is very uniform, while the elongation is up to 6%. It is beneficial to the forming force reduction and stabilization of the quenching temperature by an increase in die temperature on condition that the critical cooling rate of sheet blank is guaranteed.

关 键 词：热冲压成形 模具设计 坯料形状优化 数字化热成形试验线 模具温度 

分 类 号：TG386[金属学及工艺—金属压力加工]