Powder metallurgy material specially applied to transmission case oil pump rotors

Abstract

The invention discloses a powder metallurgy material specially applied to transmission case oil pump rotors. The powder metallurgy material comprises the following components in percentage by weight: 0.4-4% of boron carbide, 0.05-0.2% of graphite powder, 1.6-2.0% of copper powder, 0.55-0.65% of lubricant and the balance iron powder. According to the powder metallurgy material specially applied to transmission case oil pump rotors, boron carbide is used as a B-carrying agent and is mixed with the iron powder, the graphite powder, the copper powder and the lubricant; then the mixture is pressed into a part blank under the ordinary pressing pressure; the part blank is sintered; FeBX generated by reaction of the part blank in the sintering process is uniformly distributed; the enlargement of a sintering neck can be effectively accelerated; pores are rounded; pearlite is refined; the generated powder metallurgy structure is formed by the pearlite and the rounded pores, so that the yield strength and the impact strength of the powder metallurgy material can be improved. Compared with the method of adding boron strarate and taking the boron strarate as the boron-carrying agent, the boron carbide is added, so that the performance of the material is better improved.

Description

technical field [0001] The invention relates to the field of powder metallurgy, in particular to a powder metallurgy material specially used for a gearbox oil pump rotor. Background technique [0002] The effect of boron (B) on the pearlite refinement of steel and the improvement of the impact strength at medium and low temperatures is far greater than that of Ni and Mo. The content of alloying elements required to achieve the same strengthening effect is very low. The promotion of use can save a lot of expensive alloying elements for the country . And in some special purposes, such as not requiring high surface hardness, but requiring high wear resistance and impact strength, fine pearlite is the only structure that can be achieved. But common carrier FeB 17 C 0.1 The hardness is too high and the solid phase diffusion rate is too low to be used in powder metallurgy production. The strengthening method of B for dense steel materials is: adding ferroboron during the molte...

AI Technical Summary

Problems solved by technology

However, the process of forming FeBX requires the participation of hydrogen, so the yield strength of the material increases first and then decreases with the increase of boron content. Excessive boron content is not conducive to the improvement of material properties.

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