抄録
The main objective of the present work was synthetically to elucidate and evaluate the addition effects of Si, Mn and C on various properties of SUS 316 stainless steel powders produced by water-atomization of liquid metals. The results were summarized as follows:
1) Every component mainly affected particle shapes, the amount of surface oxide and metallographical phase states of powders, where especially Si and Mn gave each other some reverse effects. Consequently, apparent density, compactibility and the like were numerically correlated to Si/Mn ratio.
2) Compressibility was increased when Si: 0.6-0.9% and Mn≤0.2%, because of above-mentioned powder characteristics. On the other hand, for the higher C-content, green density less increased in the stage of plastic deformation of particles.
3) When the powders were vacuum-sintered at temperature below 1200°C, the same Si-component range as
2) gave a maximum sintered density, and also gave a lower activation energy for sintering than any other ranges.
4) The sintering rate and pore-spherodization of compacts were accelerated with increase of Si-content. Therefore, mechanical properties, especially porosity-sensitive ductility were appreciably improved in Si-rich materials which were sintered at higher temperature.
5) Corrosion resistance in boiling acid solutions was complicatedly related to every component, being overlapped by the influence of residual pore shape and oxides along grain boundary. All these sintered materials seemed stronger for boiling 65% HNO3-solution.
