The invention discloses a method for manufacturing hot-rolled dual-phase steel based on a CSP (Compact Strip Production) process. The method comprises the following steps: (1) preparing a
raw material comprising the following chemical compositions in percentage by weight: 0.055-0.070% of C, 0.40-0.50% of Si, 1.20-1.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.002% of S and the balance of Fe and unavoidable impurities; and (2) sequentially pretreating
molten steel, carrying out converter top and bottom combined blowing, refining in an LF, continuously
casting thin billet, soaking in a tunnel furnace, continuously rolling by virtue of an F1-F7 seven-stand hot
continuous rolling mill group, cooling by virtue of a
laminar cooling system, cooling by virtue of an ultra-fast cooling
system and coiling. In the method, the out-of-
furnace temperature of the
continuous casting billet passing through the tunnel soaking furnace is equal to or greater than 1130 DEG C, the initial rolling temperature in the hot
continuous rolling step is equal to or greater than 1010 DEG C, the
reduction rate in an F1 stand is equal to or greater than 40%, the
reduction rate in an F2 stand is equal to or greater than 33.3%, the temperature after the
laminar cooling and
air cooling is 600-690 DEG C, the temperature after ultra-fast cooling is 150-250 DEG C, the ultra-fast
cooling speed is 70-150 DEG C / s. The microstructures of 11.0mm-thickness 590MPa-grade dual-phase steel in the thickness direction, which is produced from a simple low C-Mn-component
system in an industrial
mass manner, are ferrite and
martensite duplex microstructures so that the dual-phase steel is excellent in comprehensive performance.