Low-carbon, low-alloy and high-formability dual-phase steel having tensile strength of greater than or equal to 590 MPa, hot-dip galvanized dual-phase steel, and manufacturing method therefor

Abstract

A low-carbon, low-alloy and high-formability dual-phase steel having a tensile strength of greater than or equal to 590 MPa, a hot-dip galvanized dual-phase steel, and a manufacturing method therefor. The steel comprises the following components, in percentage by mass: 0.04-0.12% of C, 0.1-0.5% of Si, 1.0-2.0% of Mn, P≤0.02%, S≤0.015%, 0.02-0.06% of Al, and can further comprise one or two of Cr, Mo, Ti, Nb and V, wherein Cr+Mo+Ti+Nb+V≤0.5%, and the balance is Fe and other unavoidable impurities. The manufacturing method includes smelting, casting, hot rolling, cold rolling, and rapid heat treatment processes. With the present invention, the recovery of a deformed structure, recrystallization and austenite transformation processes are changed, the nucleation rate is increased, the grain growth time is shortened, grains are refined, the strength and n value of the material are improved, and the interval range of the material performance is expanded.

Dependencies are inferred from the claim text.