High-pressure gas cylinder steel and its surface oxide scale removal method

Abstract

The invention belongs to the technical field of hot strip rolling, and in particular relates to a method for removing high-pressure gas cylinder steel and its surface oxide scale. A high-pressure gas cylinder steel in the present invention is composed of the following chemical components in weight percent: C 0.30-0.70%, Si 0.20-0.50%, Mn 0.40-1.00%, Cr 0.80-1.30%, Mo 0.15-0.40%, V 0.03 ~0.10%, Ti 0.008~0.15%, P≤0.015%, S≤0.005%, and the balance is iron and unavoidable impurities. The invention provides a medium-carbon high-silicon CrMo series hot-rolled high-pressure gas cylinder steel with a wide application range of chemical composition, and a method for suppressing the generation of red oxide scale on the surface of high-pressure gas cylinder steel with simple process and low cost by controlling the surface quality .

Description

technical field [0001] The invention belongs to the technical field of hot strip rolling, and in particular relates to a method for removing high-pressure gas cylinder steel and its surface oxide scale. Background technique [0002] Si forms a olivine phase at high temperature (Fe 2 SiO 4 ), it is easy to accumulate at the bonding surface between the iron oxide scale and the substrate and inside the iron oxide scale, making the adhesion of the iron oxide scale stronger and difficult to remove. Silicon olivine will solidify below 1173°C, if it cannot be completely removed, it will easily lead to red rust and hemp pits on the surface of the steel plate. The red iron scale on the surface of the hot-rolled coil (that is, the Fe remaining on the surface of the steel strip 2 o 3 Iron oxide scale, hereinafter referred to as red rust) is unfavorable to the performance and service performance, and also seriously affects the appearance of the steel coil. CrMo series of high-stren...

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Problems solved by technology

Panzhihua Iron and Steel adopts converter→continuous casting→regenerative heating furnace heating→hot continuous rolling (such as 30CrMo grade) to produce hot-rolled high-pressure gas cylinder steel. If the descaling effect of the rolling line is not satisfactory, thicker scale may remain and be pressed into the steel matrix during the deformation process to form scale indentation defects. The indentation of the surface scale not only seriously affects the appearance quality of the steel plate, Moreover, it is extremely detrimental to the performance and service performance of the steel plate.

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 resolved and has become one of the factors restricting the upgrading of product structure

[0011] In summary, the methods for removing the red scale on the surface of hot-rolled steel sheets mainly include mechanical descaling, high-pressure water descaling and strictly controlling the Si content in the steel to Si≤0.20%. It will bring about an increase in the production cost of hot-rolled steel sheets

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