Production and processing technology of powder metallurgy stainless steel products

Firstly, it is necessary to determine the production process of powder metallurgy stainless steel products: mold design and raw material determination - mold manufacturing - raw material mixing - mold installation and machine debugging production - stainless steel materials to be vacuum furnace sintered - machining - deburring - rust prevention and oil immersion - inspection and qualified packaging.

Powder metallurgy stainless steel products are generally made of stainless steel SS316L or SS304L, and the design process and iron material are different. Firstly, the mold cannot be used interchangeably. The sintering expansion and shrinkage rate of iron based materials is usually around 3 ‰, while the sintering shrinkage rate of powder metallurgy stainless steel materials can reach about 15 ‰, and the difference is quite significant. Moreover, the precision of finished products made of powder metallurgy stainless steel is not easy to control due to its high shrinkage rate. Sintered billets have sufficient toughness and are easy to stick to the cutting tool, resulting in poor plasticity during secondary re pressing. Therefore, the production of powder metallurgy stainless steel has certain precision limitations. It's not a problem if it can be processed appropriately, but for those that cannot be processed (such as certain irregular parts), the accuracy must be within a controllable range before powder metallurgy can be used.

Powder metallurgy stainless steel products require the use of an intermittent vacuum sintering furnace at a temperature of around 1250 degrees Celsius. After degreasing, heating, high-temperature sintering, cooling, and sintering, it takes at least 12 hours even if cooling gas is used for cooling. Vacuum sintering requires a relatively high vacuum degree, and requires a sufficient furnace of products to reduce the amount. When cooling with nitrogen gas, avoid excessive temperature, otherwise it is easy to nitride stainless steel products. After gold processing, powder metallurgy stainless steel products are directly deburred and packaged for inspection.