Method for controlling crazing defect of surface of strip steel in high-Cu steel grade

Abstract

The invention provides a method for controlling a crazing defect of the surface of strip steel in a high-Cu steel grade. In the method, Cu / Ni is controlled to be within the range of between 1.8 and 2.0, and the oxygen content is below 50 ppm; steel is calcined under reducing atmosphere, an air-fuel ratio of a heating section to a soaking section is less than or equal to 2.0, and the reheating temperature of a plate blank is more than or equal to 1,200 DEG C; and the retention time in a furnace is controlled to be within 300 minutes, a watering mode of descaling at an outlet is adopted in a rough rolling pass, which is large in lateral pressure amount, of a vertical roll, and the inlet temperature of finish rolling is lower than 1,083 DEG C. In the method, a series of comprehensive technical measures are adopted in the integral process of rough rolling and the finish rolling from smelting to steel calcining, so the inherent quality of the steel is purified, the adverse effect of Cu on the surface quality of the rolled strip steel is inhibited, the defect of crazing fine cracks distributed on the surface of the strip steel intensively is eliminated completely, the surface quality and quality yield of the strip steel are improved obviously, and the economic benefit of enterprises is increased.

Description

technical field [0001] The invention belongs to the technical field of integrated smelting and rolling production technology, and in particular relates to a method for eliminating the reticulate defects on the surface of high-Cu steel strips after rolling by comprehensively controlling the smelting production process and the slab heating and rolling process. Background technique [0002] The so-called high-Cu steel generally refers to a type of steel with a Cu content of 0.2% to 0.3% in the steel. The more common ones are steel for container plates and steel for atmospheric corrosion resistance. After the high-Cu steel is oxidized at high temperature, local enrichment (or enrichment phase) of Cu-Ni-As elements will be produced under the surface oxide iron skin. In the production process of high Cu steel, whether it is the solidification, reheating, or even rolling process of the cast slab, there are such oxidation conditions. Therefore, these production links are likely to ...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to address the above problems, to provide a comprehensive process control measure including the whole process of smelting, steel burning, rolling, etc., to suppress the adverse effect of Cu on steel quality, so as to avoid the reticulation on the surface of strip steel after rolling Defects, a method to ensure the surface quality of high Cu steel strip steel