溶融Fe-Ti合金の窒素溶解度ならびにTi窒化物生成平衡

抄録

The solubility of nitrogen and the equilibrium of the Ti-nitride forming reaction in liquid Fe-Ti alloys under the presence and absence of Ti-nitride were studied hy the sampling method at 1600, 1650 and 1700°C in the concentration range of 0-0.5% Ti.
The results are summarized as follows:
1) Solubility of nitrogen markedly increased with increasing titanium concentration, and Ti-nitride was formed at very low concentration of titanium in the liquid Fe-Ti alloys.
2) The intraction parameters, e ^(Ti) _N were found to be -0.60 at 1600°C, -0.49 at 1650°Cand -0.44 at 1700°C, and e ^(Ti) _Ti have been deduced as 0.53 (1600°C), 0.29 (1650°C), and 0.26 (1700°C).
3) The Ti-nitride which appeared in the liquid Fe-Ti-N system was identified as cubic TiN by X-ray diffraction analysis. The standard free energy of decomposition was determined as
TiN (s) =Ti+N
ΔG°=90 400-35.6T