Steel smelting process used for automobile hub bearing

Abstract

The invention belongs to the field of metallurgy, and relates to a steel smelting process, in particular to a steel smelting process used for an automobile hub bearing. The steel smelting process comprises the steps that 1, high-quality molten iron and scrap steel are added into a converter, tapping is conducted through a sliding plate, remaining steel operation is adopted, and deoxidizing is conducted on molten steel through different numbers of Al cakes according to the C content at the end; 2, aluminum is used in advance in the refining process, white slag is controlled to be kept for more than 30 min, and maintaining of deoxidization and the liquidity of the slag is reinforced in the whole refining process; 3, enough vacuum deairing time is ensured in the RH process, and the soft blowing time is ensured; and 4, double slag is adopted for covering a continuous casting tundish, so that impurities in the molten steel are adsorbed, and meanwhile secondary oxidation is prevented. According to the steel smelting process used for the automobile hub bearing, the purity of the molten steel is improved to the greatest extent, the oxygen content of a produced bearing steel for a hub reaches 5.2 ppm, the titanium content of the molten steel is 10 ppm, rating of non-metallic impurities reaches the best international level, the fatigue life of the bearing steel for the hub is prolonged, sequence continuous casting of the molten steel is achieved, and the production cost is reduced.

Description

technical field [0001] The invention belongs to the field of metallurgy and relates to a steel smelting process, in particular to a steel smelting process for automobile hub bearings. Background technique [0002] The car hub bearing unit mainly bears the weight of the car (radial load) transmitted through the suspension system, the axial load generated by the steering of the car, transmits the torque from the gearbox and the drive shaft, and makes the car move forward and backward, so it is a very Important safety piece. At present, carbon bearing steel is mainly used to produce automobile wheel bearings. The main steel types are G55Mn and G70Mn of the national standard, which are equivalent to the SAE1055M and SAE1070M grades of the American standard. In order to meet its use requirements, the bearing steel for automobile hub must have good fatigue life, cutting performance and uniform macrostructure. [0003] The quality of high-quality bearing steel for automobile whee...

AI Technical Summary

Problems solved by technology

[0004] At present, the domestic carbon bearing steel for automobile wheel bearings is basically produced by "electric furnace + refining outside the furnace + die casting or electroslag process". , In addition, the production efficiency of the mold casting process is low, and the finished product rate is also low, which seriously increases the production cost of the material

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