High-surface-quality hot-rolled pickling steel with tensile strength being 440 MPa and for automobiles and production method

Abstract

High-surface-quality hot-rolled pickling steel with the tensile strength being 440 MPa and for automobiles is composed of, by weight, 0.090-0.120% of C, 0-0.080% of Si, 1.100-1.500% of Mn, 0-0.025% of P, 0-0.006% of S and 0.015-0.040% of Als. A production method comprises the steps of conventional smelting and blank formation through continuous casting, casting blank heating, hot rolling, coiling, laminar cooling and acid pickling. The hot-rolled pickling steel for the automobiles is produced through spare production capacity of a cold rolling and acid rolling on-line production line, and the surface roughness of the pickling steel is controlled to be 0.4-1.0 micron through the last machine frame of five machine frames; the cost of the steel per ton is averagely reduced by 15% at least compared with the prior art; and the pickling steel has good extension performance, cold stamping formation performance, welding performance and cold bending performance, and the application requirements of automobile hot-rolled pickling steel are met.

Description

technical field [0001] The invention relates to an automobile plate and a production method thereof, in particular to a hot-rolled pickled steel for automobiles with a tensile strength of 440MPa and a production method thereof. Background technique [0002] As the overall overcapacity of the iron and steel industry continues to increase, low-cost manufactured products are increasingly valued by the iron and steel industry; on the other hand, the automobile industry is developing rapidly, the demand for automobile steel is increasing, and the competition in the industry is also increasing. is becoming more and more fierce, so the control of material cost is very important. The development status of the steel industry and the automobile industry has further promoted the application and development of hot-rolled pickled steel for automobiles. [0003] The thickness of hot-rolled pickled steel for automobiles is generally in the range of 2.0~6.0 mm, requiring high surface quali...

AI Technical Summary

Problems solved by technology

Its shortcomings: Due to the characteristics of the CSP production line, the compression ratio of the rolled steel is limited and the steel composition range is narrow. The steel plate shape, surface quality, and mechanical properties of the produced steel plate are worse than those of conventional hot rolling products, and cannot meet high surface quality. Requirements for hot-rolled pickled steel for automobiles

Its shortcomings: the production cost of the steel is high, the Ti content is relatively large, and the mechanical properties of the steel plate are low. It belongs to the production category of enamel steel and cannot replace the hot-rolled pickled steel for automobiles with high surface quality.

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