Stainless steel powder metallurgy is a stainless steel product manufactured by the powder metallurgy method. Compared with the stainless steel products produced by the traditional melting process, the parts produced are close to net forming, high dimensional accuracy, high material utilization rate, uniform organizational structure and so on.

What is the process of stainless steel powder metallurgy?

The process flow of stainless steel powder metallurgy is to prepare Powder – Shaping  – Sintering

1, preparation of powder: It is the first step in the production of stainless steel by powder metallurgy, which can be water atomization, the molten stainless steel will flow out of the nozzle leak, and be blown and solidified with high-pressure water to obtain stainless steel powder. The loose density of water-atomized stainless steel powder is 2.5~ 3.2g /cm3. It can also be gas atomized, the loose density of high-pressure nitrogen atomized powder is 4.8g /cm3, and the powder oxygen content is less than 10-4. Spherical stainless steel powder can also be produced by the rotating electrode powder process.

2, forming: forming pressure of 550~830 MPa.

3, sintering: Because the alloying elements in stainless steel are easy to be oxidized, it must be sintered in a protective atmosphere with very low oxygen content, if hydrogen or decomposed ammonia is used as a protective atmosphere, the dew point should be -45~-50℃. Vacuum sintering can also be used, and the sintering temperature is 1120~1150℃. The stainless steel powder can also be loaded into the envelope, vacuum sealed, cold isostatic pressed, and then hot isostatic pressing densified into the wood, the process parameter is 1050℃, and the pressure is 2 kPa.

Advantages of stainless steel powder metallurgy

Compared with ordinary cast and forged stainless steel, the alloy elements of stainless steel powder metallurgy have small segregation, small grain size, small and uniform distribution of impure inclusions, and higher mechanical properties and corrosion resistance. In particular, the high nitrogen stainless steel produced by the powder metallurgy method is much less expensive than the high-pressure melting method, and the powder metallurgy high nitrogen stainless steel has a series of excellent properties, and the application prospect is very broad. Stainless steel products prepared by stainless steel powder metallurgy can refine the microstructure and reduce the segregation of alloying elements, thus improving the properties of the material. In addition, it can save raw materials and energy consumption to achieve low-carbon, green and environmental protection. It has been widely used in machinery, the chemical industry, ships, automobiles, instruments, and other industries.