Abstract: The process and properties of 700MPa grade hot rolled dual phase steel DP700 (/% : C 0.08 ~ 0.12 ,Si 0.08 ~0.12,Mn 1.30 ~ 1.150,P≤ 0.015,S ≤0,005 ,Cr 0.50 ~0.70,Ca ≥0.0015, Al≥0.015) development at Baosteel Meishan 1780 hot rolling mill are summarized. The developed plate has superior surface quality, its properties are Yield strength≥400 MPa,Tensile strength≥700 MPa,Elongation after fracture N≥ 17% (b = 20 mm, L₀= 80 mm) , Hole expansion rate ≥35% ,50% survival rate fatigue limit 475 MPa. Results show that the steel DP700 is one of new material for Auto industry with good application prospect.

摘要： 阐述了在宝钢梅山基地1780热轧机生产线上开发的700MPa级热轧双相钢DP700（/%:C 0.08～0.12,Si 0.08～0.12,Mn 1.30～1.150,P≤0.015,S≤0.005,Cr 0.50～0.70,Ca≥0.0015,Al≥0.015）工艺和性能,该钢板表面质量优良,屈服强度≥400 MPa,抗拉强度≥700 MPa,断后伸长率≥17%（b=20 mm,L₀=80 mm）,扩孔率≥35%,50%存活率的疲劳极限达475 MPa。结果表明,DP700钢是一种具有良好应用前景的新型汽车零部件材料。