Practicing on Producing DDQ Cold Rolling Deep-Drawn Steel by HMPT-BOF-RH-CSP-CR in LY Steel

CSP is the characteristics of high cooling rate and tiny precipitated particles of second phase particles, and suitable to produce high strength strip steel. It is a real challenge to produce cold-rolling deep-drawn grade by using CSP-CR technology. This article briefly introduced the chemical and physical metallurgy processes of producing cold-rolling deep drawn grade by HMPT-BOF-RH-CSP-CR technology in LY steel, and then emphatically analyzed the influence of compositions control and technology control to the property of cold-rolling deep-drawn DDQ, finally discussed the influence of steel cleanliness, namely inclusions to the property of deep drawn steel. The results showed: (1) the main chemical components of DDQ were [C] <= 35 ppm, [Si] <= 0.01%; (2) the contents of the main harmful and inclusion formation elements were [S] <= 0.009%, [N] <= 20 ppm, [O] <= 24 ppm; (3) the main performance of the cold-rolled stamping using steel produced by SPHE are transverse direction Rp0.2=163MPa, Rm=294MPa, n=0.22, r=2.47, and vertical direction Rp0.2=165MPa, Rm=298MPa, n=0.21, r=2.37, 45 degrees direction Rp0.2=169MPa, Rm=304MPa, n=0.20, r=2.28.