誘導加熱法を用いた高強度合金鋼の急速焼結

抄録

To study rapid sintering by induction heating, we used high strength-alloyed steel powder, partially diffused powder of 4mass%Ni-1.5mass%Cu-0.5mass%Mo-0.3mass%C-bal. Fe. In this rapid sintering, the degassing process, diffusion of additional alloying elements and evolution of a Martensitic or Bainitic structure in the matrix were proved to play a very important role. Thus, the substantial controlling factors were the holding time for degassing and the diffusion. Experimental results showed that this process required a higher sintering temperature compared with the a continuous furnace, but that the sintered materials processed a higher radial crushing strength (R.C.S) by changing the holding time. Although the high strength-alloyed steel requires, in general, a longer time for diffusion of additional alloying elements, the holding time was only 3-4 minutes in the present process. The optimum condition appeared to be a sintering temperature of 1573 K for 120-180s with a temperature increase time of 65 s; the RCS data attained was about 1400MPa.