DP590冷轧双相钢不同退火温度下的连续冷却相变行为研究

Study on Continuous Cooling Phase Transformation Behavior of DP590 Cold-Rolled Dual-Phase Steel at Different Annealing Temperatures

摘要:

双相钢是由铁素体和马氏体组成的一种高强钢，具有优异的强塑性、连续屈服和较低的屈强比，而广泛地应用于汽车行业。研究了DP590冷轧双相钢在退火温度分别为800和830 ℃下的连续冷却相变行为及组织演变规律。结果表明：退火后，在不同冷却速率下，双相钢的热膨胀曲线出现“平台”和上升趋势，这是由于过冷奥氏体的相变引起的；同时显微组织显示，通过调整退火制度，可以控制其多边形铁素体和马氏体的体积比，并获得分布均匀且晶粒细小的铁素体和马氏体双相组织。

Abstract:

Duplex steel composed of ferrite and martensite， is widely applied in automobile industry for its excellent strength and plasticity， continuous yield and lower yield strength ratio. The continuous cooling transformation behavior and microstructure evolution of DP590 cold rolled duplex steel at 830℃ and 800℃ were investigated in this paper. The results showed that the thermal expansion curves of dual-phase steels all had a "plateau" and an upward trend at different cooling rates， due to the transformation of undercooled austenite. Moreover， the microstructures of steel presented that the volume ratio of ferrite and martensite could be controlled by annealing schedule， and duplex steel consisted of ferrite and martensite with uniform distribution and fine grains could be obtained.