Method for implementing direct conveying and charging of high-strength low alloy steel continuously-cast bloom

Abstract

The invention discloses a method for implementing direct conveying and charging of a high-strength low alloy steel continuously-cast bloom. The method comprises the following steps of: 1) quickly cooling the continuously-cast bloom on a continuous casting roller bed to the temperature of below 500 DEG C at the speed of 2 to 5 DEG C per second; and 2) directly charging the continuously-cast bloom into a heating furnace after quick cooling and after the temperature recovery time of over 5 minutes. By the method, the surface of a steel plate is prevented from cracking when the high-strength low alloy steel continuously-cast bloom is produced by adopting a common thermal conveying and thermal charging process, so that direct conveying and charging and even thermal conveying of the high-strength low alloy steel continuously-cast bloom become possible, and energy conservation and consumption reduction are realized. For a steel mill with limited casting blank piling site, the method can solve the contradiction between yield improvement and insufficient casting blank piling site.

Description

technical field [0001] The invention belongs to the technical field of metal material processing, and particularly relates to a method for directly sending high-strength low-alloy steel continuous casting slabs to rolling mills or workshops. The thermal charging of the slab at the temperature in the two-phase region has obvious effects on the cracks on the surface of the steel plate. [0002] Background technique [0003] For some iron and steel plants that mainly produce high-strength low-alloy steel, especially those with a compact layout and insufficient slab stacking space, the traditional production mode of slab stack cooling-furnace heating-rolling has seriously affected Accelerated production rhythm and smooth logistics have become the restrictive links for such steel mills to improve production efficiency. [0004] The technology of direct feeding and loading of continuous casting slabs has obvious effects on shortening the process flow and alleviating the contradi...

AI Technical Summary

Problems solved by technology

[0005] However, cracks are prone to appear on the surface of the steel plate during the hot delivery process of the high-strength low-alloy steel continuous casting billet. On the one hand, due to the difference between the surface and internal temperature of the slab, the phase transformation is not synchronized, resulting in temperature stress and structural stress on the surface of the slab. The precipitation on the austenite grain boundary has a weakening effect on the grain boundary, which leads to the brittleness of the steel at high temperature. These two factors work together to make the high-strength low-alloy steel continuous casting slab prone to cracks during hot delivery.

[0006] Therefore, the high-strength low-alloy steel continuous casting slabs produced in China basically adopt the production mode of stacking or air cooling first, and then reheating in the furnace after the surface temperature of the slab is cooled below 500°C. This mode seriously restricts the smelting and rolling process. Towards the development of a compact integrated model of steelmaking-continuous casting-rolling