Kinetics for Diffusion of Alloying Elements into Fe-base Particles During Sintering - Application to Alloy Element Redistribution of Mixtures of Fe-2Cr, Fe-2Mn, Fe-2Mo and Fe-2Ni

摘要

The purpose of this study was to create an understanding of the redistribution of alloy elements in binary systems during sintering of Fe-2Mn, Fe-2Cr, Fe-2Mo and Fe-2Ni. The sintering was carried out in a dilatometer under 90% N_2 and 10% H_2 atmosphere. Length changes were monitored to provide information of necking, sintering shrinkage and phase transformations. Concentration profiles were obtained by measuring the alloying content on polished cross sections of the Fe-base particles. The influence of morphology and surface oxides on diffusion was also investigated. Sintering at 1120℃ entailed difficulties with oxides on the Mn-particles. Diffusion of Mn into Fe-base particles was completely prevented if Mn-oxides were present. Photo acoustic spectrometry measurements showed that sintering of the Fe-2Cr system at 1250℃ enabled reduction the oxide content. For the Fe-2Mo system the same result for oxide reduction was obtained at 1120℃.