Novel bearing steel self-homogenizing grain refiner and preparation method thereof

Abstract

The invention relates to a novel bearing steel self-homogenizing grain refiner and a preparation method thereof. The novel bearing steel self-homogenizing grain refiner is prepared from Mg powder, Fe powder and Mg particles, the mass ratio of the Mg powder to the Fe powder to the Mg particles is (4.9-5.1) to (91.9-92.1) to (2.9-3.1), and the surface porosity of a pressing block of the Fe powder, the Mg powder and the Mg particles needs to be kept to be about 12%-15%. When the novel bearing steel grain refiner is put into molten steel, a micro-burst effect is generated, so that effective components in the refiner are automatically and uniformly distributed in the molten steel, and the utilization rate of Mg in the molten steel is increased. Mg fills up the surface defects of the grain boundary through segregation at the grain boundary, so that the surface tension on the two-phase interface is reduced, and the nucleation speed is increased; and meanwhile, the grain boundary energy is reduced, the grain growth driving force is reduced, the grain growth is limited, and the strength, toughness and other properties of the bearing steel are improved.

Description

technical field [0001] The invention belongs to the technical field of metal material grain refinement, and relates to a novel self-uniform grain refiner for bearing steel. Background technique [0002] Bearings are subjected to great pressure and friction during work, so the bearing steel is required to have high and uniform hardness and wear resistance, as well as a high elastic limit. The uniformity of the chemical composition of the bearing steel, the content and distribution of non-metallic inclusions, and the distribution of carbides are very strict, and it is one of the most stringent steel types in all steel production. [0003] If the grains in the bearing steel are too coarse, the number of grain boundaries inside the material will be reduced, making it easier for cracks to expand, significantly affecting the properties of the steel, resulting in a reduction in the strength, plasticity and toughness of the steel. The reduction of the above mechanical properties wi...

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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

Moreover, after the current grain refiner is added to the molten steel, it is difficult to ensure that the active ingredients of the refiner can be evenly distributed in the molten steel. grain effect

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