A kind of refining slag used for bearing steel production and its smelting process

Abstract

The invention discloses refining slag for bearing steel production and a smelting process of the refining slag, wherein the refining slag comprises the following components in percentage by weight: less than or equal to 6% of SiO2, 40-50% of Al2O3, 45-55% of CaO, less than or equal to 8% of MgO, less than or equal to 0.05% of TiO2 and less than or equal to 2% of Fe2O3, the particle size is controlled at 3-45mm, and the alkalinity is controlled at about 10; and the smelting process comprises the main steps of predeoxidizing after converter tapping, starting to alloy at 80s after starting to tap (the tapping quantity is about 35t), adding one of aluminum iron, carbon powder, alloy and lime in sequence, impacting and smelting by using a steel flow, and then, adding the other material; adding 600Kg of the refining slag at one step after a refining furnace is seated; and adding a deoxidizer by strictly executing the principles of multiple batches and small quantity. By using the refining slag, the problem for controlling the O content as well as B, D and TiN inclusions in a bearing steel production process is simultaneously solved; and the refining slag plays a critical role in improving the quality of bearing steel.

Description

technical field [0001] The invention belongs to the technical field of steelmaking and refining, and relates to a slagging material used in the refining process of bearing steel and a smelting process thereof. Background technique [0002] The working environment of the bearing is very complicated, so it is required to have high strength and wear resistance. The national standard requires Ti content ≤ 50ppm, O content ≤ 12ppm, B-type inclusions ≤ 2.0, D-type inclusions ≤ 1.0; and some The requirements of high-end customers are even higher than the national standards, and the requirements are: Ti content ≤ 15ppm, O content ≤ 8ppm, and the requirements for B and D inclusions are 0.5 grades stricter than the national standard. Everyone knows that the main factor affecting these properties is various inclusions in molten steel. Controlling these inclusions is a key factor in the smelting and production of bearing steel and a guarantee for the quality and performance of bearing s...

AI Technical Summary

Problems solved by technology

[0008] To sum up, in the prior art, there is no smelting production technology for bearing steel that can control the Ti content to ≤15ppm and the O content to ≤8ppm at the same time, and the requirements for B and D inclusions are stricter than the national standard. coverage, in general, only partially meets the requirements

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