Sintering of Zr pre-alloyed and water atomized 316L stainless steel powder for various content of Si was performed. The maximum sintered density was obtained at 0.8 mass% of Si for the powder pre-alloyed 0.05 mass% of Zr. Excess addition of Si -for example, 1.20 mass%- inhibited the densification by the growing of Si-containing oxide particles. The pre-alloying of Si increased the ferrite content of powder but the correlation between the ferrite content and the level of densification was not observed. The 316L powder pre-alloyed 0.8mass%Si and 0.05mass%Zr had finer grain size and this made a contribution to the densification by the volume diffusion.
