【摘要】 以重轨钢液为研究对象,建立可以定量描述稀土铈在重轨钢液中行为特性的热力学模型,利用该热力学模型,可以预测在不同洁净度条件下重轨钢液中稀土赋存状态及夹杂物组成的变化规律.结果表明:重轨钢液中初始氧质量分数的增大,有利于稀土氧化物和稀土氧硫化物的析出;钢液中初始硫质量分数的增大,有利于稀土硫化物和稀土氧硫化物的析出;1783 K温度条件下重轨钢液中Ce2O3夹杂析出的必要条件为钢中氧硫的活度比大于等于0.19,Ce2S3夹杂析出的必要条件为钢中氧硫的活度比小于等于0.39,CeS夹杂向Ce2O2S夹杂转变的条件为钢中氧硫的活度比在0.53~0.96之间;随着洁净度的提高,重轨钢液中溶解态稀土的质量分数逐渐增加.更多还原

【Abstract】 A thermodynamic model was developed quantitatively to analyze the behavior of the RE element cerium in the molten steel for heavy rail,in which the existence state of Ce and constituents of inclusions can be forecasted under different cleanliness.The results showed that in the molten steel the increasing mass fractions of initial oxygen and sulfur benefit the precipitation of Ce oxide/Ce oxysulfide and that of Ce sulfide/Ce oxysulfide,respectively.The necessary conditions for Ce2O3 and Ce2S3 precipitations at 1 783 K are that the activity ratio of oxygen to sulfur is greater than or equal to 0.19 and less than or equal to 0.39,respectively.The necessary condition for transforming CeS into Ce2O2S is that the activity ratio of oxygen to sulfur is 0.53～0.96.With the cleanliness improved,the mass fraction of Ce solute increases gradually.更多还原