powder metallurgy steel

Powder metallurgy iron-based structural parts are structural parts manufactured by powder metallurgy technology with iron powder or alloy steel powder as the main raw material. The requirements for this kind of parts are to have sufficiently good mechanical properties, wear resistance, good machining performance, and sometimes heat and corrosion resistance. Powder metallurgy iron-based parts are widely used in various fields of the national economy. Especially in the automotive industry, 60% to 70% of powder metallurgy iron-based parts in developed countries are used in automobiles, such as camshafts, exhaust valve seats, water pump impellers and various gears. The characteristics of powder metallurgy iron-based structural parts: (1) The parts have high dimensional accuracy, which can be less and without cutting; (2) Porosity. Compared with dense metals, iron-based powder metallurgy structural parts have evenly distributed pores. Uniformly distributed pores can eliminate the lubricating oil to improve the anti-friction properties of the material, and the uniformly distributed spherical pores are also conducive to the fatigue resistance of the parts under the condition of multiple impacts with small energy. However, pores can reduce the mechanical properties of the material such as tensile strength, elongation after fracture, and impact toughness, and affect the material's corrosion resistance, thermal conductivity, electrical conductivity, and magnetic permeability. However, according to the application requirements, the pore size and pore distribution can be controlled by adjusting the material composition, particle size and process. However, the smaller the pore size, the higher the manufacturing cost. (3) No segregation of alloying elements and fine and uniform crystal grains. The alloying elements in the iron-based structural materials are realized by adding alloying element powders and mixing them. Without smelting, the number and types of alloying elements added are not affected by solubility limitations and density segregation, and segregation-free alloys and pseudo-alloys can be prepared. Pores hinder the growth of grains, so the grains of iron-based structural materials are finer.