连续退火参数对980 MPa级冷轧双相钢组织和性能的影响

采用带钢连续退火模拟试验机,研究了连续退火过程中加热速率、两相区保温温度和过时效温度对冷轧双相钢DP980组织和性能的影响规律。研究结果表明,适当提高加热速率有利于马氏体晶粒的细化和带状组织的改善,当加热速率达到45℃/s时可获得较高的强度和塑性。退火温度直接决定了硬质第二相的体积分数、分布和形貌,在800℃左右进行退火保温可以获得良好的综合性能,保温温度过低或过高都会导致强塑性匹配较差。随着过时效温度的降低,强度升高,伸长率下降,试验钢退火后加工硬化系数明显增大。

Effects of continuous annealing parameters on microstructure and mechanical properties of 980 MPa cold-rolled dual-phase steel

The continuous annealing simulator was used to investigate the influences of heating rate, intercritical annealing temperature and over-aging temperature during continuous annealing process on microstructure and mechanical properties of DP980. The research results show that to increase heating rate can refine martensite grain and is benefit to remove banded structure, and better strength and plasticity can be obtained when heating rate is 45??/s. The intercritical annealing temperature determines the volume fraction, distribution and morphology of second phase. Strength or plasticity would be poor when annealing temperature is too low or too high, and heating and soaking at about 800?? can get better comprehensive mechanical properties. With over-aging temperature decreasing, strength increases, elongation decreases and work hardening coefficient increases significantly.