Method for rolling carbon steel and low alloy steel large-piece-weight extra thick composite blank

Abstract

The invention relates to a method for rolling a carbon steel and low alloy steel large-piece-weight extra thick composite blank and belongs to the technical field of a blank rolling process in the metallurgical industry. The method comprises the rough rolling step and is characterized in that the rough rolling step comprises the following two stages: a rough rolling initial pass stage and a rough rolling pony-roughing pass stage; in the rolling initial pass stage, the temperature is not lower than 1,050 DEG C, the rolling speed is 1.0 to 1.5m / s and the rolling acceleration is 1.0 to 1.5m / s<2>; in the rough rolling initial pass stage, a high-temperature low-speed low-pressure rolling manner is adopted and the rolling reduction per pass is 10 to 20mm; in the rough rolling pony-roughing pass stage, a high-temperature low-speed high-pressure rolling manner is adopted and the rolling reduction is set into 40 to 60mm per pass. According to the invention, the rough rolling step is carried out in two stages and in the rough rolling initial pass stage, the high-temperature low-speed low-pressure rolling manner is adopted, so that impact of a roll to the blank in the biting process of the extra thick composite blank is effectively reduced and a composite weld joint at the edge of the blank is effectively prevented from being cracked.

Description

technical field [0001] The invention relates to the technological improvement of billet rolling in the metallurgical industry, and is specially designed to be a rolling method of large unit weight and extra thick composite billets of carbon steel and low alloy steel. Background technique [0002] During the rough rolling and biting process of the blank, the impact of the roll on the blank is relatively large. Since the large single-weight composite continuous casting blank is only welded around the casting blank and the welding depth is limited, it is easy to cause the composite weld seam at the edge of the blank to crack, making the The entire billet will be rejected, and even the roll will be damaged, resulting in direct economic losses. The ordinary rolling process of carbon steel and low alloy steel continuous casting slab usually adopts high temperature, low speed and large reduction in the high temperature stage of rough rolling, and the reduction is generally not less...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a rolling method of carbon steel and low-alloy steel large unit weight and extra thick composite billet. Large, resulting in the problem that the composite weld at the edge of the stucco is easy to crack

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