韧性断裂准则在超高强钢辊弯成形工艺中的应用

Research on application of ductile fracture criteria in roll forming process of ultra high strength steel

对某牌号的超高强钢进行拉伸、弯曲、V型件辊弯成形试验,对比常用的6种韧性断裂准则,得出这6种韧性断裂准则均不能给出一个适用于板料各种工艺下断裂的固定临界值。根据辊弯成形工艺特点,采用Brozzo韧性断裂准则,预测相对弯曲半径R/T=2下的超高强钢辊弯成形的破裂现象。预测结果与实验结果表明,Brozzo韧性断裂准则可以应用于超高强钢辊弯成形中。

Ultra high strength steel（UHSS） has been used widely in automotive industry,and roll forming process is one of the effective forming technologies to produce UHSS profiled parts.This research conducted uniaxial tensile test,bending test and roll forming test,compared six kinds of ductile fracture criteria,and concluded that the six ductile fracture criteria could not provide a cracking critical value suitable for all kinds of sheet metal forming processes.According to the characteristics of roll forming process,Brozzo ductile fracture criterion was adopted to predict the fracture with the relative bending radius R/T=2 in the UHSS roll forming simulation.The simulation result agreed with the experimental result,which proved Brozzo ductile fracture criterion could be applied to UHSS roll forming process.