High-strength thin-specification steel plate with excellent shape and production method thereof

Abstract

The invention discloses a high-strength thin-specification steel plate with an excellent shape. The steel plate comprises the following chemical components by weight percent: 0.10 to 0.20 percent of C, 0.10 to 0.30 percent of Si, 1.4 to 1.70 percent of Mn, 0.02 to 0.06 percent of Nb, 0.008 to 0.025 percent of Ti, 0.20 to 0.40 percent of Cr and the balance of Fe and inevitable impurities, a metallographic structure is ferrite and pearlite, and the grain size is more than or equal to level 9.5. The production method comprises the steps of smelting in a converter, continuous casting, heating, rolling and cold control, and the heating temperature is controlled between 1150 DEG C and 1190 DEG C; the segmented rolling is adopted, the rolling temperature is controlled to be more than or equal to 1080 DEG C at the rough rolling stage, the pressing rate of each pass is not less than 15 percent, the rolling temperature is controlled at 900 to 950 DEG C at the fine rolling stage, and the final rolling temperature is controlled at 760 to 800 DEG C; the cooling speed is controlled to be less than or equal to 10 DEG C per second when controlling the coldness, the red returning temperature of the steel plate is controlled at 500 to 600 DEG C; and the steel plate is cooled in the air to the room temperature. The performances such as high strength, high flexibility and low uneveness are integrated on the thin-specification steel plate, the production process is simple, the heat treatment does not needed, and the yield is increased.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgical materials, in particular to a high-strength thin-gauge steel plate with excellent plate shape and a production method thereof. Background technique [0002] The thin-gauge steel plate produced by the medium-thick plate has always had the problem that the shape and strength of the steel plate are not ideal. In order to ensure the strength and impact toughness of the steel plate, the cooling rate of the steel plate is generally required to be faster. In this case, the steel plate obtained is a steel plate with troostite + ferrite or bainite + ferrite structure, and the shape of the steel plate is It is prone to buckling; or in order to ensure the shape of the steel plate, reduce the cooling rate of the steel plate to obtain a steel plate with a microstructure of pearlite + ferrite structure, but the strength of the steel plate can generally only reach about 420MPa, and it is difficult to ...

AI Technical Summary

Problems solved by technology

[0002] The thin-gauge steel plate produced by the medium-thick plate has always had the problem that the shape and strength of the steel plate are not ideal

In order to ensure the strength and impact toughness of the steel plate, the cooling rate of the steel plate is generally required to be faster. In this case, the steel plate obtained is a steel plate with troostite + ferrite or bainite + ferrite structure, and the shape of the steel plate is It is prone to buckling; or in order to ensure the shape of the steel plate, reduce the cooling rate of the steel plate to obtain a steel plate with a microstructure of pearlite + ferrite structure, but the strength of the steel plate can generally only reach about 420MPa, and it is difficult to exceed 450MPa In addition, the impact toughness of the steel plate is also relatively poor; using low-temperature rolling or ultra-low carbon methods can achieve better steel plate performance, but low-temperature rolling is not easy to control the shape of thin-gauge steel plates, and smelting ultra- Low-carbon slabs will increase smelting costs

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