Effects of cold rolling reduction ratio on microstructure and properties of high strength hot dip galvanized dual phase steel

Under laboratory conditions, the study about performance of the high strength hot dip galvanized dual phase steel with different cold rolling reduction ratio was carried. The results show that typical dual phase structure with ferrite and martensite can be observed in the experimental steel. With the increase of cold rolling reduction ratio, volume fraction of martensite is gradually increased, and the steel's tensile strength is reached 910 MPa, yield strength and initial stiffness index n value and plastic strain ratio r value are changed little, elongation rate is reached above 14%.