增氮析氮法生成气泡去除钢液中显微非金属夹杂物

Micro non-metallic inclusion removal from molten steel with gas bubbles generated by the nitrogen absorbing and releasing method

为了进一步完善增氮析氮法生成气泡去除钢液中显微非金属夹杂物技术,研究了真空处理时间、充氮压力、气体类型等因素对钢中全氧和显微非金属夹杂物的影响.结果表明:减压处理过程中,钢液中非金属夹杂物可为过饱和气体氮气形成气泡提供非均相形核核心;增氮析氮法可有效地降低钢中全氧,去除钢中显微非金属夹杂物;真空处理时间越长,钢中全氧和显微非金属夹杂物数量越低,当真空处理时间为30 min时钢中全氧去除率达到了81.6%,而且全氧质量分数最低达到7×10-6.

The effects of vacuum processing time, nitrogen pressure and gas types on the total oxygen and micro non-metallic inclusions in molten steel were investigated to further improve the technology of micro non-metallic inclusion removal from molten steel with gas bubbles generated by the nitrogen absorbing and releasing method. It is found that in the vacuum treatment process, non-metallic inclusions can act as heterogeneous nucleation sites for the evolution of supersaturated nitrogen from molten steel to form bubbles on their surface, the total oxygen decreases, and these micro non-metallic inclusions are effectively removed by the nitrogen absorbing and releasing technology. The longer the vacuum processing time, the lower the content of total oxygen and amount of micro non-metallic inclusions in steel will be, and the removal rate of total oxygen reaches to 81. 6% after the steel is vacuum treated 30 min, with the lowest total oxygen content about 7 ×10^-6 in steel.