基于圆筒拉深试验,获得了1 000 MPa级先进高强度钢拉深时破裂的临界点和极限拉延比(LDR).研究了Hill、Barlat和BBC 3种不同屈服准则的数值仿真效果.结果表明:1 000 MPa级双相钢LDR值为2.07,且Barlat屈服准则模拟结果与实际试验相符.对断口进行扫锚电镜(SEM)观测,发现1 000 MPa级双相钢有别于传统板材,其拉深断裂模式为沿板材厚向45°的韧性切向断裂,无明显颈缩现象.
Through the cup drawing test,the onset crack and limiting drawing ratio(LDR) of 1 000 MPa dual phase(DP) steel were identified.Three yielding models: Hill,Barlat and BBC were compared in the numerical simulation.The results show that LDR of 1 000 MPa DP steel is 2.07.And Barlat yield criterion is suitable for actual test.Unlike traditional sheet materials whose crack has obvious necking,the crack mode of 1 000 MPa DP is a tensile shear fracture and cracks are on alternating 45° planes,through thickness.