Research and development of 600 MPa grade hot-rolled dual-phase steel with low silicon content

Aiming at the problems such as high cost and poor surface quality of traditional hot-rolled dual-phase steel, this article takes a experimental steel with low silicon content composition system as the object, and based on the production line of rlot strip Rolling Mill of Angang Co., Ltd., process characteristics of the ultra-fast cooling system in the continuous rolling production line of Hot Strip Rolling Mill of Angang Co., Ltd., a 600 MPa grade hot-rolled dual phase steel with low cost and high surface quality was developed. Through the matching design of chemical composition and hot rolling process, the developed 600 MPa grade hot-rolled duplex steel has a typical dual-phase microstructure, with a ferrite volume percentage of about 85% and a ferrite grain size of about 6.0 μ m; The yield strength of the strip is 360-390 MPa, the tensile strength reaches 600-630 MPa, the yield strength ratio is 0.57-0.63, and the elongation is greater than 27%. The developed strip have excellent mechanical properties, good surface quality, and low cost, meeting the manufacturing requirements of automotive wheels and other components.