Powder metallurgy material for rotor of oil pump of gearbox

Abstract

The invention discloses a powder metallurgy material for a rotor of an oil pump of a gearbox. The powder metallurgy material for the rotor of the oil pump of the gearbox comprises, by weight percentage, 0.15%-0.9% of stearic acid boron B(C16H35O2)3, 0.3%-0.6% of graphite powder, 1.6%-2.0% of copper (Cu) powder, 0.55%-0.65% of lubricant, and the balance iron powder. Preferentially, the lubricant is zinc stearate. Due to the fact that the zinc stearate which is low in melting point and low in decomposition temperature is adopted to serve as a carrying agent of boron and to be mixed with the iron powder, the graphite powder, the copper powder and the lubricant, growth of a sintering neck is improved, and pores are rounded. An introducing mode of the boron in the powder metallurgy material and the optimal range of the addition amount of the boron are determined, the wear-resisting performance is more than 2.6 times that of the standard under the condition that the surface hardness is low, cost is reduced, and tensile strength is high.

Description

technical field [0001] The invention relates to the field of powder metallurgy, in particular to a special powder metallurgy material 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. However, the hardness of the common carrier FeB17C0.1 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 molt...

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Problems solved by technology

Under the normal powder metallurgy sintering temperature, the liquid phase dissolution of ferroboron cannot occur, and the solid phase diffusion needs to be sintered for more than 200h to achieve alloying, which is too far from the 5h required for normal sintering. In addition, the hardness of FeB17C0.1 is Hv1400, so direct pressing It will reduce the compact density by 0.4g / cm3 and cannot be used in powder metallurgy production

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