440MPa-grade cold-rolled strip steel and production method thereof

Abstract

The invention discloses 440 MPa-grade cold-rolled strip steel and a production method thereof, and belongs to the field of strip steel production. The method comprises the following steps: heating continuously cast plate blank at a heating temperature of 1200-1250 DEG C to obtain heated plate blank, wherein the continuously cast plate blank consists of the following chemical components in percentage by mass: 0.003%-0.009% of C, 0.08%-0.12% of Si, 1.4%-1.65% of Mn, 0.08%-0.10% of P, less than or equal to 0.003% of S, 0.025%-0.035% of Alt, and the balance of iron and inevitable impurity elements; performing hot rolling on the heated plate blank to form hot-rolled strip steel, and controlling a final rolling temperature of a hot-rolling process to be 840-900 DEG C; rolling the hot-rolled strip steel, and controlling a rolling temperature to be 580-620 DEG C; performing cold rolling on the rolled strip steel after pickling to form cold-rolled strip steel; annealing the cold-rolled strip steel in an annealing furnace; and flattening the annealed strip steel. The 440 MPa-grade cold-rolled strip steel has tensile strength of 440 MPa, and has excellent forming performances, so that high-quality P-containing high-strength IF steel can be obtained.

Description

technical field [0001] The invention relates to the field of steel strip production, in particular to a 440MPa cold-rolled steel strip and a production method thereof. Background technique [0002] In order to adapt to the development trend of weight reduction, consumption reduction, safety and environmental protection in the automobile industry, with the development of modern automobile manufacturing technology and the improvement of automobile use requirements, new changes have taken place in steel for automobile panels. Steel and substrates for automobile bodies From the low-carbon steel plate with low drawing level in the past to the ultra-low carbon IF steel plate with high deep drawing level, the surface condition has developed from the simple bare plate in the past to various electroplating, hot-dip, composite plated, galvanized steel plates, etc., and in the car The proportion of body use is increasing year by year, and the development and development of stamped stee...

AI Technical Summary

Problems solved by technology

[0004] The embodiment of the present invention solves the technical problem of serious color difference on the surface of the steel strip containing P-containing high-strength IF steel by providing a 440MPa grade cold-rolled steel strip and its production method

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