The traditional stainless steel sintering of stainless steel parts generally uses solid phase sintering. However, a large number of pores remain in the stainless steel during solid phase sintering, which reduces its density and performance. In recent years, people have begun to use super-solid line liquid phase sintering to make stainless steel pre-alloyed powder form a liquid phase during sintering, and the liquid phase fills the pores through flow to improve the density and performance of the sintered body.
Different from ordinary liquid phase sintering, stainless steel parts processing super solid phase line liquid phase sintering is the sintering of pre-alloyed powder, and it is always a single phase during the sintering process. The sintering temperature is between the solid phase line and the liquid phase line. At this temperature, the pre-alloyed powder particles form a liquid phase in the grains, at the grain boundaries and on the surface of the particles. The particles are rearranged under the action of the capillary force of the liquid phase. The places where the surface curvature changes greatly will be preferentially dissolved and pass through the liquid phase. Flowing mass transfer, precipitation in the depressions or pores of large particles, to achieve the purpose of rapid transfer of substances, so as to make the sintered body compact.
Stainless steel parts processing, 316L stainless steel obtained by super solid phase sintering at 1400 ℃, its density, hardness, wear resistance and corrosion resistance are higher than those of solid phase sintering at 1200 ℃. However, because the sintering temperature of stainless steel parts is too high, the crystal grains will grow excessively and cause overburning. Care should be taken to avoid