Production technology of steel used for pipe line steel electrode

Abstract

The invention relates to a production technology of steel used for a pipe line steel electrode, which sequentially comprises converter steel making technology, argon station refining technology and continuous casting technology; specific technological parameters of the converter steel making technology are as follows: (1) in molten iron in a converter, the weight percentage content of S is less that or equal to 0.003 percent; (2) converter finishing point control is as follow: steel tapping temperature is 1680 to 1690 DEG C, and in tapped molten steel, the weight percentage content of C is 0.04 to 0.06 percent; (3) converter finishing point slag-thickening operation is as follows: magnesium balls and lime dry slag are added at the converter finishing point to lead final slag in the steel tapping course to be thickened; and (4) final deoxidation technology is as follows: when steel tapping reaches 1/3, final deoxidizer and refining slag are added, and stirring is conducted with heavy argon; at the interval between 4/5 of the steel tapping and finish of the steel tapping, argon blowing is conducted for 25 to 35 seconds; and the refining slag consists of the lime and fluorite, and weight ratio of the lime to the fluorite is 2:0.4 to 0.6. The production technology well controls contents of carbon, silicon and oxygen in the production process, thus improving the steel-making success rate of the steel used for the pipe line steel electrode.

Description

technical field [0001] The invention relates to a steel production process, in particular to a steel production process for pipeline steel welding rods. Background technique [0002] Pipeline steel welding rod steel is used for welding pipeline steel. The traditional production process of pipeline steel welding rod steel generally includes converter steelmaking process, argon station refining process, ladle furnace refining process, continuous casting process, etc. [0003] Pipeline steel welding rod steel, such as pipeline steel welding rod steel H08GX, has strict composition requirements: [C]≤0.09%, [Si]≤0.04%, [S]≤0.006%, [P]≤0.015%. [0004] The traditional production process of pipeline steel electrode steel generally has the following problems: [0005] 1. Due to the ladle furnace refining process, it is easy to increase [C] and return [Si], and [C] and [Si] are not easy to control. [0006] 2. The molten steel [S] is low, and [Ti] and [O] in the steel are unstable. ...

AI Technical Summary

Problems solved by technology

[0005] 1. Because the ladle furnace refining process enters the ladle furnace for heating, it is easy to increase [C] and return [Si], and [C] and [Si] are not easy to control

[0006] 2. The molten steel [S] is low, and [Ti] and [O] in the steel are unstable. During the ladle furnace refining process (LF furnace refining), adding alloys to increase [Ti] and adding desulfurizers to remove S will result in long production cycles. If the temperature is low, the electrodes need to be heated up, which will lead to secondary oxidation, resulting in an increase in [O] in the steel, which will easily lead to the interruption of continuous casting of molten steel in the continuous casting process. High [O] will easily generate billet bubbles, which will affect the interior of the billet. quality, thus affecting the welding performance of the electrode

[0007] Due to the above reasons, the traditional production process of steel for pipeline steel welding rods has a low refining rate, usually less than 50%.

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