Effect of primary deoxidation products of Al2O3, ZrO2, Ce2O3 and MgO on TiN precipitation in Fe-10mass%Ni alloy

Effect of Al2O3, ZrO2, Ce2O3 and MgO particles with mean diameter of 0.8 to 1.5 mum on the precipitation of TiN during solidification and holding at 1 400 degreesC has been studied in an Fe-10mass%Ni alloy. The values for the number of particles per unit area, N-A, and the mean diameter, (d) over ba r (A), of TiN and TiN+MxOy (M=Al, Zr, Ce, and Mg) particles have been measu red as a function of initial contents of Ti (50 to 990 mass ppm) and N (200 to 290 mass ppm), and holding time (0 and 60 min). The N-A values of the T iN+MgO particles are considerably higher than those of the TiN+MxOy (M=Al, Zr, and Ce) particles, while the da values of the former particles, which a re found to be independent of solidification mode, are smaller than those o f the latter particles. The (d) over bar (A) values of TiN and TiN+MxOy (M= Al, Zr, and Ce) particles in dendritic solidification are smaller than thos e in nondendritic one, whereas an opposite trend is observed with respect t o the N-A values. The (d) over bar (A) values of the TiN and TiN+MxOy parti cles were found to remain unchanged, but the N-A values tended to slightly increase with holding time.