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采用Hopkinson拉杆试验系统对800 MPa级冷轧双相钢(DP800)进行动态拉伸试验,动态拉伸选择应变速率为500、1000和2250 s~(-1).通过比较试验结果得出:双相钢的塑性延伸强度Rp0.2和抗拉强度Rm与应变速率的关系呈指数形式增加;DP800在高应变速率塑性变形会产生绝热温升效应,计算可得DP800在应变速率为2250 s-1时拉伸变形产生的绝热温升为89℃.基于J-C(Johnson-Cook)模型和Z-A(Zerilli-Armstrong)模型,对DP800的本构模型进行了研究,并对J-C模型应变速率效应多项式进行二次化修正,修正后的J-C模型相较于J-C模型对DP800在不同应变速率下的平均可决系数从0.9228提高到0.9886.
The dynamic tensile test of 800 MPa cold-rolled dual-phase steel (DP800) was carried out by using the Hopkinson rod test system. The tensile strains were selected to be 500, 1000 and 2250 s -1 by dynamic tensile test. The relationship between plastic extension strength (Rp0.2) and tensile strength (Rm) and strain rate of phase steel increases exponentially. DP800 produces adiabatic temperature increase effect at high strain rate plastic deformation. Calculating the DP800 at a strain rate of 2250 s-1 The adiabatic temperature rise induced by tensile deformation was 89 ° C. Constitutive model of DP800 was studied based on JC (Johnson-Cook) model and ZA (Zerilli-Armstrong) model, and the strain rate effect polynomial of JC model In the modified JC model, the average coefficient of determination of DP800 at different strain rates from JC model is increased from 0.9228 to 0.9886.