Establishment and Applications of Thermal Forming Limit Margin Field Graph for Automobile Components

Abstract

Abstract: In hot stamping processes, the sheet maintained in a high temperature state and the temperature varied at different positions, for which traditional method was difficult to evaluate the sheet formability. Temperature dependent 3D forming limit graph was a new method to evaluate formability of hot stamping components, however, the prediction of forming margin remained a blank. To solve the problems discussed above, a way to calculate the forming margin was proposed herein based on the temperature dependent 3D forming limit graph. Then, combining numerical simulations and theoretical analyses, a safe margin field graph for evaluating high strength steel sheet in hot stamping was established. Using the safe margin field graph, different hot stamping processes of an automobile B pillar were analyzed by numerical simulation and were compared to experiments. Results show that the proposed forming margin field graph may effectively predict the fracture positions and cracked degrees of HSS components in hot stamping at different process parameters and blank shapes.

Key words: high strength steel(HSS) sheet, hot stamping, forming limit diagram, forming margin field graph

摘要： 在热冲压工艺中，热冲压钢板处于高温状态，不同位置温度分布有明显差异，传统方法难以评价冲压件的成形性，考虑温度的三维成形极限图能有效评价热冲压件的成形性能，但无法判断热冲压件的安全裕度。针对上述问题，在考虑温度的三维成形极限图的基础上，首先提出了成形裕度的计算方法；然后结合数值模拟和理论分析手段，构建了适用于评价高强钢板热冲压的安全裕度云图；最后对某汽车B柱热冲压不同工艺过程进行了仿真分析，并与试验进行了对比。结果表明，在不同工艺参数和板料尺寸下，构建的裕度云图均能有效预测高强钢板热冲压件的开裂部位和程度。

关键词: 高强钢板, 热冲压, 成形极限图, 成形裕度云图

CLC Number:

TG306

CUI Junjia, HU Ming, LI Guangyao, . Establishment and Applications of Thermal Forming Limit Margin Field Graph for Automobile Components[J]. China Mechanical Engineering.

崔俊佳, 胡明, 李光耀, . 汽车零部件热成形极限裕度云图的构建与应用[J]. 中国机械工程.

References

[1]NADERI M, UTHAISANGSUK V, PRAHL U, et al.A Numerical and Experimental Investigation into Hot Stamping of Boron Alloyed Heat Treated Steels[J].Steel Research International，2008, 79(2): 77-84.
[2]王敏，张春，张宇，等.汽车高强钢纵梁热冲压试验研究[J]. 中国机械工程，2016，27(3)：391-397.
WANG Min, ZHANG Chun, ZHANG Yu, et al. Experiments on Hot Stamping of Car Caring of High Strength Steel [J]. China Mechanical Engineering, 2016，27(3)：391-397.
[3]庄百亮，单忠德，姜超，等.汽车防撞梁超高强钢热成形工艺研究[J].中国机械工程，2012，23(2)：225-228.
ZHUANG Bailiang, SHAN Zhongde, JIANG Chao, et al.Research on Ultra-high-strength Hot Stamping Process of Automobive Anti-collision Beam[J]. China Mechanical Engineering, 2012, 23(2)：225-228.
[4]LI Nan, SUN Chaoyang, GUO Ning, et al. Damage Investigation of Boron Steel at Hot Stamping Conditions[C]//11th International Conference on Technology of Plasticity.Nagoya, 2014: 19-24.
[5]盈亮，史栋勇，胡平，等.基于连续介质损伤力学的高强度钢板热成形性数值预测[J].机械工程学报，2016,52(4):36-44.
YING Liang, SHI Dongyong, HU Ping, et al. Numerical Prediction of the Formability during Hot Forming of High Strength Steel Based on Continuum Damage Mechanics[J]. Journal of Mechanical Engineering, 2016,52(4):36-44.
[6]SHI D Y, YING L, HU P, et al. Experimental and Numerical Determination of Thermal Forming Limit Diagrams (TFLD) of High Strength Steel 22MnB5[C]// 11th International Conference on Numerical Methods in Industrial Forming Processes：Shenyang, 2013: 406-413.
[7]CUI Junjia, SUN Guangyong, XU Junrui, et al. A Method to Evaluate the Formability of High-strength Steel in Hot Stamping[J]. Materials and Design, 2015, 77: 95-109.
[8]NACEUR H, DELAMZIERE A, BATOZ J L, et al. Some Improvements on the Optimum Process Design in Deep Drawing Using the Inverse Approach[J]. Journal of Materials Processing Technology, 2004, 146(2): 250-262.
[9]WEI Donglai, CUI Zhenshan, CHEN Jun. Optimization and Tolerance Prediction of Sheet Metal Forming Process Using Response Surface Model[J].Computational Materials Science, 2008, 42(2): 228-233.
[10]ZHUANG Weimin, ZHANG Mengxi, CHEN Yanhong. Error Analysis of FLC Experimental Data at Warm/Hot Stamping Conditions[J]. Chinese Journal of Mechanical Engineering, 2014, 27(4): 730-737.
[11]ZHANG Huawei, LIU Xianghua, LIU Lizhong, et al. Study on Nonuniform Deformation of Tailor Rolled Blank during Uniaxial Tension[J]. Acta Metall. Sin. (Engl. Lett.), 2015, 28(9): 1198-1204.
[12]CHANG Ying, TANG Xinghui, ZHAO Kunmin, et al. Investigation of the Factors Influencing the Interfacial Heat Transfer Coefficient in Hot Stamping [J]. Journal of Materials Processing Technology, 2016, 228: 25-33.
[13]高云凯，邓有志，曹伟.超高强度钢车身B柱加强板热成形工艺参数多目标优化[J].中国机械工程，2011，22(5)：621-629.
GAO Yunkai, DENG Youzhi, CAO Wei. Multi-objective Optimization for Ultra High Strength Steel B-pillar of Car Body Hot Forming Process Parameters[J]. China Mechanical Engineering, 2011，22(5)：621-629.