研究1000MPa的双相钢(DP钢)在室温下的准静态拉伸行为与应变速率(10^-2、10^-1、10^-1s^-1)的关系。结果表明,在准静态拉伸条件下,DP钢的拉伸性能是与应变速率相关的。随着应变速率提高,材料的屈服强度、抗拉强度、屈强比和加工硬化指数明显升高,而均匀伸长率、断裂伸长率略有下降;另外,应变速率对材料的应变强化系数影响不大。利用SEM分析了DP钢的断口形貌和微观组织随应变速率的演化及与拉伸行为的关系。研究可为超高强度钢在车身上的应用提供技术支持。
The relationship between strain rate (10^-2、10^-1、10^-1s^-1) and quasi-static tensile behavior of 1 000 MPa DP (Dual Phase) steel was studied at room temperature in the present paper. The results show that the properties of DP steel under quasi-static tension is strain rate dependent. Its yield strength, tensile strength, yield ratio and work hardening exponent increase with increasing strain rates. And uniform elongation, ultimate Elonga- tion slightly decreases. In addition, strain rate dosen't have distinct influence on strength coefficient. The micros- turctural evolution of DP steel and the fracture surfaces with different strain rates were observed using SEM. The tensile deformation behavior was also discussed in order to explain how strain rate influences tensile properties of DP steel. The study can provide experimental support for the application of AHSS in the automobile body.