MIM process for ultrahigh-strength and high-toughness steel parts

Abstract

The invention discloses an MIM process for ultrahigh-strength and high-toughness steel parts, and belongs to the technical field of metal powder injection molding. The MIM process comprises the following steps of raw material selection, feed preparation, injection molding, catalytic degreasing, thermal degreasing and sintering, solution treatment and aging treatment, Wherein the procedure of thermal degreasing and sintering specifically comprises the step of a green body subjected to catalytic degreasing being sequentially subjected to thermal degreasing, deoxidation and decarbonization and sintering. The MIM process for the ultrahigh-strength and high-toughness steel parts has the characteristics of being simple, convenient, economical and efficient, metal parts which are ultrahigh in strength, high in toughness and high in hardness and have three-dimensional complex shapes can be manufactured in a large scale within a short time, by means of improvement on raw material components and a thermal degreasing and sintering process, the strength, toughness and hardness of the steel parts can be remarkably improved, the requirements of 3C and other industries for high-performance parts can be met, and huge economic benefits are generated.

Description

technical field [0001] The invention belongs to the technical field of metal powder injection molding, and in particular relates to a MIM molding process of ultra-high-strength and high-toughness steel parts. Background technique [0002] With the development of mobile intelligent terminal products in the direction of more functions, larger sizes, and more complex structures, more and more high-strength mechanical components are required, and the weight of products continues to increase. In order to meet the needs of lightweight products and high strength parts, one of the solutions is to choose materials with high specific strength. The specific strength of titanium alloys ranks first among metal materials, but the poor machinability and high price of titanium alloys greatly limit the use of titanium alloys. Among the existing metal materials, the specific strength comparable to that of titanium alloy is only ultra-high-strength steel. Ultra-high-strength steel not only ha...

AI Technical Summary

Problems solved by technology

[0004] However, at present, metal parts formed by MIM technology are difficult to meet the standards of ultra-high strength and high toughness at the same time, and cannot meet the needs of mobile smart terminal products for high structural strength and high toughness metal parts

For example, the Chinese invention patent with application number 202010154524.1 discloses an injection molding method for high-strength and high-toughness metal parts. The material composition is Ni 17-18%, Co 8.5-9.5%, Mo 4.5-5%, and the balance is Fe. After sintering and heat treatment, the yield strength only reaches 1350MPa, and the elongation rate is 6%. The Chinese invention patent with application number 202010852638.3 discloses an injection-molded ultra-high-strength steel. The material composition is C<0.1%, Ni15.5-19.5%, Co 7-10%, Mo 4-6%, Ti<1.5%, the balance is Fe, although the yield strength can reach 1500MPa level, but the elongation is only up to 6%, and with the increase of yield strength, the elongation decreases ; CN 103981436 A discloses a metal powder injection molding maraging steel, the material composition is C≤0.08%, Ni 17-19%, Co 8-10%, Mo 4.5-6.5, the balance is Fe and unavoidable impurities, although the elongation ≥ 10%, but the strength is still low, only the tensile strength can reach 1500MPa