【摘要】 引入拉弯比来表征高强度双相钢板在不同凸模圆角半径下的拉弯应力状态,根据不同的拉弯比判定不同的成形断裂模式,在剪切断裂试验平台上进行双相钢板的拉弯试验,并对断裂试样的微观组织形貌进行分析.结果表明:高强度双相钢的剪切断裂属于韧性断裂;凸模圆角半径越小及板料强度越高,板料越容易发生剪切断裂.更多还原

【Abstract】 Stretch-bending is a typical method for sheet stamping forming.Different fracture failure modes occur on advanced high strength dual phase steel based on different stress state.For example,shear fracture occurs under tight radius stretch-bending condition.In this paper,a stretch-bending ratioαwas introduced to indicate different stress states to determine the failure mode:necking or shear fracture.Stretchbending experiments of DP steels were conducted and fracture morphology was observed.The results show that shear fracture still belongs to ductile fracture,and tighter punch radius or higher DP strength leads to shear fracture much more easily.更多还原