The advantages and disadvantages of powder metallurgy stainless steel and the means to overcome them

If the smelting process is used to produce stainless steel products, due to the difficulty of cutting, there will be a series of arrangements in the manufactured parts, such as poor dimensional accuracy and insufficient surface roughness. In solving similar problems in applications, powder metallurgy plays a crucial role.

Compared with stainless steel produced by traditional smelting process, powder metallurgy stainless steel has the advantages of producing parts close to net forming, high dimensional accuracy, high material utilization rate, uniform organizational structure, etc., and has been widely used in machinery, chemical industry, shipbuilding, automobile, instrumentation and other industries.

But it's not that powder metallurgy stainless steel is perfect. Due to the presence of pores inside, the mechanical properties, wear resistance, and corrosion resistance of powder metallurgy stainless steel are greatly reduced, which seriously limits the application of this product.

However, research has shown that almost all properties of powder metallurgy stainless steel improve with increasing density. Therefore, as long as the density of powder metallurgy stainless steel is increased and its porosity is reduced, it can play a key role in improving the performance of powder metallurgy stainless steel.

The reason why there are a large number of voids left inside powder metallurgy stainless steel is closely related to the use of solid-phase sintering method. Therefore, some users have started to replace it with ultra solid line liquid-phase sintering, so that the stainless steel pre alloy powder forms a liquid phase during sintering. The liquid phase fills the pores through flow, thereby improving the density and properties of the sintered body Unlike ordinary liquid-phase sintering, ultra solid-phase liquid-phase sintering is the sintering of pre alloyed powder, and during the sintering process, it is always a single phase, and the sintering temperature will always be between the solid-phase line and the liquid-phase line. Moreover, the particles are rearranged under the action of liquid phase capillary force, and mass transfer is achieved through liquid phase flow, thereby achieving densification of the sintered body.

In addition, adding appropriate strengthening phases is also one of the main ways to improve the performance of powder metallurgy stainless steel, especially its hardness and wear resistance, which are improved as a result