Method for controlling form of carbide in bearing steel

Abstract

The invention discloses a method for controlling the form of carbide in bearing steel. The method comprises the following steps: smelting the bearing steel in a ladle refining (LF) furnace, transferring into a vacuum degassing (VD) furnace, and smelting the changed refining slag components for 10-15 minutes under the process parameters of the temperature of 1520-1570 DEG C and the vacuum pressure of 30-100 Pa. The invention has the advantages of simple process and low cost, and has obvious effects on controlling the Mg content in the bearing steel, further controlling the form of the carbide in the bearing steel, improving the distribution of the carbide in the bearing steel and improving the circularity and length-diameter ratio of the carbide in the bearing steel.

Description

technical field [0001] The invention relates to iron and steel metallurgy technology, in particular to a method for controlling the morphology of carbides in bearing steel. Background technique [0002] Carbide is an essential condition to ensure the basic performance of bearings, such as hardness, strength, wear resistance and fatigue life. It is difficult to achieve a dispersed distribution of billet carbides in bearing steel containing 1.0%C and 1.5%Cr. [0003] Predecessors have done a lot of work on the influence of Mg on carbides in steel. It is believed that trace amounts of magnesium can improve the morphology, size and distribution of carbides in nickel-based and iron-based superalloys, and can significantly improve their performance characteristics. The addition of magnesium can alleviate the segregation of elements and eliminate the eutectic carbide network. The action mechanism of magnesium on carbides in bearing steel has been studied, and it is believed that ...

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Problems solved by technology

[0006] 1. The yield of magnesium is too low, and the yield of magnesium is only 0.76%-1.50% when metal magnesium is added directly; the yield of adding the form of nickel-magnesium alloy (magnesium content accounts for 19.3wt%) is 5.8%

[0007] 2. It is difficult to control the magnesium content in the steel. Since there are different degrees of splashing in the molten steel when adding magnesium, as the gas phase pressure decreases, the splashing is serious and the volatilization of magnesium is intensified, so it is difficult to make the magnesium in the molten steel The content is kept within an appropriate range

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