A kind of refining method of spring steel

Abstract

The invention discloses a refining method for spring steel. The refining method comprises converter smelting, LF ladle refining, RH vacuum treatment and blowing-in of inert gas. During the process of converter smelting, the content of carbon in molten steel during tapping control ranges from 0.15 wt% to 0.25 wt%. A CaO-SiO2-MgO slag system is adopted during the process of LF ladle refining, and the basicity ranges from 1.8 to 2.5; and refined slag comprises 50-60 wt% of CaO, 22-28 wt% of SiO2, 3-6 wt% of Al2O3, 10-15 wt% of MgO, 0.5-1 wt% of MnO+FeO and 2-4.5 wt% of CaF2; and through selection of the CaO-SiO2-MgO slag system during the process of LF ladle refining, by controlling the alkalinity of the refined slag and controlling the components of the refined slag, non-metallic inclusions in the steel are reduced, and erosion of the refined slag to a ladle lining is reduced.

Description

technical field [0001] The invention belongs to the technical field of metallurgical manufacture, and in particular relates to a refining method of spring steel. Background technique [0002] As a key material required for major equipment manufacturing and national key project construction, spring steel is widely used in aircraft, automobiles, railway vehicles and other transportation tools and construction machinery and other equipment. Materials for springs and other shapes of springs with similar functions. In view of the harsh working conditions of spring steel, it is required that spring steel must have excellent comprehensive performance; at the same time, starting from energy saving and economy, and in reducing the weight of vehicles, motorcycles and other transportation tools, it is also required to reduce the weight of springs. The quality of steel puts forward higher requirements. [0003] The quality of spring steel is related to the chemical composition of stee...

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Problems solved by technology

However, the C-type inclusions cannot meet the quality requirements of high-quality spring steel (C-type 0-1.0 grade); the literature "Smelting and continuous casting process practice of valve spring steel 54SiCr6" (Special Steel, 2015, 36(4)) It is recorded that the basicity of LF refining slag is 0.5-0.8, and the process of "KR hot metal-BOF-LF-510mm×390mm slab continuous casting-150mm×150mm slab rolling-high-speed wire rolling" makes A, B, C, The grades of D and Ds inclusions are all ≤0.5. The disadvantages are that the slag has low alkalinity and low viscosity, and there is no vacuum treatment of molten steel, which may easily cause gas absorption during the refining process of molten steel.

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