Method for controlling oxide scales on surface of moderate thick plate

Abstract

The invention provides method for controlling oxide scales on the surface of a moderate thick plate. The method comprises the following steps that: the heating temperature of a plate blank is controlled in the range of 1150 DEG C to 1200 DEG C; the heating temperature of the plate blank placed in a descaling machine is controlled to be lower than or equal to 1150 DEG C, the descaling machine adopts a single-step descaling mode, and the water pressure is from 18 MPa to 22 MPa; the target temperature of a rough rolling treatment for beginning rolling is controlled to be lower than or equal to 1100 DEG C, wherein the descaling is carried out by the rough rolling and the steel conversion in the first step, and the press-down rate of the rough rolling in the last treatment step is controlled in the range of 8% to 11%; and finally the descaling is carried out after finishing the first step of finish rolling. The method has the advantages of simplicity in treatment, convenience in operation, small investment, rapid effect and high production efficiency. In addition, the formation rate of secondary oxide scales on the high-temperature plate blank after being descaled is decreased; the primary oxide scales generated during the heating are removed; the press-in effect of the oxide scales on the surface is lightened obviously; and the surface defect of a rolled steel plate is lowered from original 7% to 1%, thereby improving the surface quality of the steel plate obviously.

Description

technical field [0001] The invention belongs to the technical field of steel rolling technology, and in particular relates to a production method capable of reducing oxide scales on the surface of low-alloy high-strength medium-thick steel plates. Background technique [0002] Due to the influence of chemical composition, rolling and cooling process and other factors in the actual production process of low-alloy high-strength medium and heavy plates, surface quality problems such as scale indentation often occur. The indentation of surface oxide scale not only seriously affects the appearance quality of the steel plate , and it is extremely detrimental to the performance and service performance of the steel plate. [0003] At present, domestic iron and steel enterprises pay more attention to the dimensional accuracy and mechanical properties of the steel plate, lack of sufficient attention to the pressing of scale, coupled with the wide application of some energy-saving tech...

AI Technical Summary

Problems solved by technology

[0002] Due to the influence of chemical composition, rolling and cooling process and other factors in the actual production process of low-alloy high-strength medium and heavy plates, surface quality problems such as scale indentation often occur. The indentation of surface oxide scale not only seriously affects the appearance quality of the steel plate , and it is extremely detrimental to the performance and service performance of the steel plate

[0003] At present, domestic iron and steel enterprises pay more attention to the dimensional accuracy and mechanical properties of the steel plate, lack of sufficient attention to the pressing of scale, coupled with the wide application of some energy-saving technologies such as high-temperature hot rolling and short-time heating, resulting in this The problem has not been completely solved, and it has become one of the factors restricting the upgrading of product structure, which has always troubled various plate manufacturers

[0004] Manufacturers at home and abroad have used methods such as controlling the heating atmosphere and changing the composition design to solve such problems, but due to difficult operation, difficult process control, low production efficiency, and unsatisfactory effects, the application is limited.