22MnB5超高强钢热冲压成形工艺及试验

Hot Stamping Forming Processes and Experiments of 22MnB5 Ultra-high Strength Steels

考虑材料的热物理性能参数、力学性能与温度的关系,利用ABAQUS软件建立了22MnB5超高强钢热冲压过程的热力耦合有限元模型,选用合适的热冲压工艺参数进行数值分析,得到了坯料热冲压成形的应力应变分布,并以板料初始温度为变量,研究不同初始温度对零件厚度分布、回弹及冷却速率的影响。进行了板料初始温度为900℃的22MnB5超高强钢热冲压试验,零件厚度分布及回弹量与模拟结果基本吻合,各区域淬火组织均为板条状马氏体,由于零件底部的淬火冷却速率较大,马氏体组织更加均匀细小。

Considering the thermal physical property parameters ana mechanics periormance as the functions of temperature, a thermo-mechanics coupling FEA model of hot stamping processes with 22MnB5 ultra-high strength steel was established using ABAQUS software, and the stress and strain distributions of the blanks during hot stamping forming processes were obtained by the numeri- cal analyses with the appropriate hot stamping processing parameters. The effects of different initial temperatures on the thickness distributions, springbacks and cooling rates of the parts were studied. The hot stamping experiments of 22MnB5 ultra-high strength steel were carried out with initial temperature of 900℃, thickness distributions and springbacks of hot stamping parts show better fitness with the numerical simulation, and the quenched microstructure of each regions is typical acicular martensite. Besides, due to the cooling rate at the bottom of the part is much larger, the martensite microstructure is more uniform and fine.