1000MPa级连续退火双相钢的组织与性能研究

Study on Microstructure and Properties of Continuous Annealing DP1000 Dual-phase Steel

在实验室试制了1000 MPa级连续退火双相钢,利用光学显微镜、SEM、TEM以及拉伸试验对双相钢的微观组织和力学性能进行检测。结果表明,保温温度830℃,保温时间60 s,快冷至过时效温度240℃,过时效时间240 s,可以得到屈服强度535 MPa、抗拉强度1145 MPa、屈强比0.47、伸长率13%,具有较好综合性能的高强双相钢;抗拉强度随过时效温度的升高呈下降趋势,屈服强度、伸长率和屈强比呈上升趋势,在过时效温度为360℃时,出现屈服平台。

1000 MPa grade dual-phase steel was piloted in laboratory.Optical microscopy,scanning electron microscopy,transmission electron microscope and tensile tests were used to characterize the microstructure and mechanical properties.The results indicate that soaked at 830 ℃for 60 s,then rapidly cooled to 240 ℃,the dual phase steel can get excellent mechanical properties.The yield strength is 535 MPa,the tensile strength is 1145 MPa,the yield ratio is 0.47 and the elongation percentage is 13%;the tensile strength reduces with over-ageing temperature increasing.The yield strength,yield ratio and elongation percentage increase with over-ageing temperature increasing.The yield point appears at 360 ℃.