A kind of 440c stainless bearing steel grain refiner and preparation method thereof

Abstract

The invention relates to a 440C stainless bearing steel grain refiner and a preparation method thereof. The 440C stainless bearing steel grain refiner includes Mg powder, Fe powder and nano C powder, and the Fe powder, Mg powder and nano The mass ratio of C powder is 93.9-94.1:4.9-5.1:0.9-1.1. The 440C stainless bearing steel grain refiner provided by the present invention effectively avoids the adhesion of Mg in the compressed refiner through the nano-C powder therein, and at the same time, the nano-C powder reacts with the oxygen in the molten steel to generate The fine CO bubbles can make the Mg particles quickly break away from the block refiner, so that the magnesium is evenly distributed in the molten steel. During the solidification process of molten steel, magnesium will segregate at the grain boundary to fill the surface defects of the grain boundary, thereby reducing the surface tension on the two-phase interface, increasing the nucleation speed, reducing the grain boundary energy and reducing the grain boundary energy. The driving force of grain growth limits the growth of grains and improves the strength and toughness of 440C stainless bearing steel.

Description

Technical field [0001] The present invention belongs to the field of grain refinement technology for metal materials, involving a grain refining agent for 440C stainless steel bearing steel. Background [0002] As a stainless steel bearing steel, 440C has a carbon content of 1.0% and a chromium content of 16% to 18%. It is mainly used for the manufacture of bearing parts working in corrosive environments and lubrication-free strong oxidation atmospheres. 440C has good high temperature dimensional stability, so it can also be used as a corrosion-resistant high temperature bearing steel. In addition, it can also be used to manufacture high-quality knives, such as medical scalpels, scissors, etc. Bearings are subjected to extremely high pressure and friction during operation, so 440C bearing steels are required to have high and uniform hardness and wear resistance, as well as high elastic limits. The requirements for the uniformity of the chemical composition of the bearing steel, t...

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Problems solved by technology

Under such high temperature conditions, it will not only consume a lot of energy to raise the temperature, but also inevitably oxidize the raw materials, resulting in a certain loss

In addition, at the temperature of steelmaking, magnesium is very easy to gasify and quickly floats to the surface of molten steel, and it is difficult to play its role in refining grains.

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