To clarify the mechanism of CaS formation on the oxide inclusion of the CaO–Al₂O₃ system, the sulfide capacities of solid oxides was measured in the present study. The results show that the sulfide capacity of (12CaO·7Al₂O₃; C₁₂A₇) was much larger than of other compounds, and increased with temperature. The value for C₁₂A₇ was larger than that measured for the liquid oxide of the same composition. Furthermore, the diffusion behavior of sulfur in solid steel to the inclusion of the CaO–Al₂O₃ system, was investigated using a diffusion couple. After heating at 1473 K for 72 h, in the case of C₁₂A₇, the intensity of sulfur in the oxide was high, but the formation of CaS was not detected. This suggests that the formation of CaS was suppressed around the C₁₂A₇ particles by the diffusion of sulfur in the solid oxide.

为了阐明CaS形成在CaO–Al ₂ O ₃系统的氧化物夹杂物中的机制，在本研究中测量了固体氧化物的硫化容量。结果表明：（12CaO·7Al ₂ O ₃； C ₁₂ A ₇）的硫化容量比其他化合物大得多，并且随温度升高而增加。C ₁₂ A ₇的值大于相同组成的液态氧化物的测量值。此外，硫在固态钢中对CaO–Al ₂ O ₃夹杂的扩散行为系统，使用扩散对进行了研究。在1473 K下加热72小时后，在C ₁₂ A ₇的情况下，氧化物中的硫强度较高，但未检测到CaS的形成。这表明通过硫在固体氧化物中的扩散，抑制了在C ₁₂ A ₇颗粒周围的CaS的形成。