A method of producing thin-gauge medium-carbon hot-rolled steel sheets with good surface quality using csp

Abstract

The invention provides a method for producing a thin-gauge medium carbon hot-rolled steel plate with good surface quality by using CSP. The method comprises the following steps of: refining and alloying to enable the chemical components of molten steel to be medium carbon steel components in Q235B; forming a blank by casting; heating a casting blank; descaling by using high-pressure water after discharging from a furnace; rolling; carrying out laminar cooling by using an air water atomization and cooling manner to a coiling temperature; reeling; and cooling to a room temperature. The hot rolled product has the thickness of 0.8 to 1.9mm. The method is mainly combined with a CSP production line, and effectively solves the surface defects such as peeling and pitting easily occurring in the carbon Q235B in the production of the CSP production line. The method ensures the usability, and meanwhile effectively solves the problems that iron oxide scale has poor adhesive force in the heating process of the steel plate, in the rolling process, peeling easily occurs, the oxide film of a roller easily peels off and causes the pitting on the surface of strip steel, and the iron oxide scale haspoor uniformity and is difficult to remove. The production cost can be reduced by more than 40 yuan per ton of steel, and the judgment-changing rate caused by the surface defects is reduced by more than 90%.

Description

technical field [0001] The invention relates to a production method of Q235B steel plate, which exactly belongs to a method for producing thin-gauge medium-carbon hot-rolled steel plate with good surface quality by using CSP. Background technique [0002] Thin gauge Q235B with a thickness of less than 2.0mm is one of the most widely used steel grades on the market. Thin gauge Q235B is generally produced by ironmaking→steelmaking→continuous casting→hot rolling→pickling→cold rolling. The production process is long and the production cost is high. [0003] The short-process CSP process can directly produce thin-gauge hot-rolled steel sheets with a thickness of less than 2.0mm, which can be used to replace traditional cold-rolled steel sheets and replace cold with heat. Since pickling, cold-rolling and other process links are omitted, the CSP process is adopted The thin specification Q235B produced can effectively shorten the manufacturing process and reduce production costs. ...

AI Technical Summary

Problems solved by technology

[0009] The present invention overcomes the difficulty in controlling the surface quality of carbon Q235B in the prior art, and is prone to peeling and pitting, and provides a method that not only has a thickness of less than 2mm, but can replace cold with heat, and has excellent surface quality, reducing production costs. A method for medium-carbon Q235B hot-rolled steel plates, which can be compared with the existing technology of more than 40 yuan per ton of steel, and reduce the rate of change of judgment caused by surface defects by more than 80%.

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