| Title |
The Effects of Phosphorus on Sintering Characteristics of Gas Atomized |
| Authors |
손광석(Kwang Seok Son); 나형용(Hyung Yong Ra) |
| Abstract |
The Fe-Cr-C alloys having high hardness and good wear resistance have been used as the wear resistance materials, valve seat, tappet, etc. mainly made by sintering of powder. For the examination of the role of P that is added with gas atomized Fe-Cr-C alloy powder which has a finer microstructure than chemical reduction powder in view of liquid phase and phase sta ilization, this study was carried out. In this study, Fe-14wt%Cr-1.77wt%C alloy powder compact was sintered for 1 hr at 1170℃ in H2 atmosphere. The effects of P were examined by OM, SEM, EDS, DSC and micro Vickers hardness of quenched specimen. During sintering, P was diffused throughout Fe(γ) matrix, and changed it from FCC to BCC structure and the sintering rate was increased by rapid self-diffusivity, but the hardness of quenched specimen decreased because the amount of FCC phase which carried out martensitic transformation decreased. And liquid phase (Fe3P + Fe matrix) asisted that P diffused to matrix, but the excess liquid phase hampered densification for increasing swelling effect. |