980 MPa级冷轧DP钢组织及性能的过时效工艺实验室研究

Laboratory Study on Overaging Process for Structure and Properties of 980 MPa Grade Cold-Rolled DP Steel

文章研究对象为M钢厂工业在产的980 MPa高强冷轧双相(DP)钢,在790℃退火温度下,通过Multipas多功能连续退火实验装置,进行了过时效工艺对其组织性能的研究。进一步扫描电镜、透射电镜观察实验钢组织,拉伸试验机检测其性能,评估了不同过时效温度对组织性能的影响。过时效温度290~370℃范围内升高,实验钢马氏体组织含量并未变化,其微观形貌由板条逐步岛状化;340℃温度过时效时,马氏体分解。过时效温度增加,实验钢弯曲性能呈正比例变化,抗拉强度递减而屈服强度无趋变。过时效温度为340℃时,材料力学性能最佳,强塑积(AT×σb)为16.53 GPa·%。

The research object of this article is the 980 MPa high-strength cold-rolled dual phase(DP)steel produced by M steel factory in industrial production.The microstructure and properties of the steel were studied using a Multipas multifunctional continuous annealing experimental device at an annealing temperature of 790℃ using the overaging process.Furthermore,the structure of the experimental steel was observed by scanning electron microscope and transmission electron microscope,and its properties were tested by tensile testing machine.The effects of different over-failure temperatures on the microstructure and properties were evaluated.The content of Martensite in the experimental steel does not change when the over aging temperature rises in the range of 290~370℃,and its micro morphology is gradually island shaped from flat noodles;Martensite decomposes when overaged at 340 C.As the aging temperature increases,the bending performance of the experimental steel shows a positive proportional change,and the tensile strength decreases while the yield strength does not tend to change.The mechanical property of the material is best when the overaging temperature is 340℃,and it's strong plastic product(ATxo b)can reach on 16.53GPa·%.