Abstract: The diagrams of forming MgO ·Al₂O₃, 2MgO·SiO₂, 3Al₂O₃ , 2SiO₂ and 2MgO·2Al₂O₃ ·5SiO₂ phase predominance area during refining process of stainless steel 316L (/% : 0. 02C, 0. 51 Si, 1. 15Mn, 0. 030P, .001S, 16. 77Cr, 10. 12Ni, 2. 07Mo, 0. 040N, 0. 006Ti, 0. 004Al) in equilibrium condition after deoxidation are obtained by using thermodynamic calculation method, and the thermodynamic conditions for formation and transformation of various inclusions have been studied and analyzed. Results show that at 1 873 K as the solution Al content in liquid is less than 0. 001 % and the solution Mg content is less than 2 x 10^-7% , it is available to form the better deformable 2MgO·2Al₂O₃·5SiO₂ low-melting-point inclusions； as solution Al content in liquid is less than 1. 7 x 10^-4 % , there is no spinel inclusions MgO·Al₂O₃ formed in liquid ； and the formation area of high-melting-point inclusions 2MgO ·SiO₂ and 3Al₂O₃ , 2SiO₂ is largest. Practice results show that the thermodynamic condition for modification treatment on high-melting-point inclusions 2MgO · SiO₂ and 3Al₂O₃·2SiO₂ by adding Ca is sufficient, as solution oxygen content in 180 t LF liquid of stainless steel 316L is 0. 002 0% , the refining end［O］ is 0. 001 5% by feeding silicon-calcium wire 2 m/t, and the rating of C-type inclusions in 2mm cold rolled sheet is 0. 5 ~ 1. 0, the main composition of inclusions is CaO·Al₂O₃·SiO₂.

摘要： 采用热力学计算方法得出316L不锈钢（/%:0.02C,0.51Si,1.15Mn,0.030P,0.001S,16.77Cr,10.12Ni,2.07Mo,0.040N,0.006Ti,0.004Al）精炼过程中脱氧平衡后形成MgO·Al₂O₃、2MgO·SiO₂、3Al₂O₃·2SiO₂、2MgO·2Al₂O₃·5SiO₂优势区图,研究和分析了各类夹杂物生成与转变的热力学条件。结果表明,在1 873 K时,当钢液中的溶解Al含量低于0.001%和溶解Mg含量低于2×10^-7%时才能形成低熔点变形能力较好的2MgO·2Al₂O₃·5SiO₂类夹杂物;当钢液中溶解Al含量在1.7×10^-4%以下,钢液中不形成MgO·Al₂O₃尖晶石夹杂;2MgO·SiO₂与3Al₂O₃·2SiO₂类高熔点夹杂物形成区域最大。实践表明,加Ca对高熔点夹杂物2MgO·SiO₂与3Al₂O₃·2SiO₂变性处理的热力学条件充足,当316L不锈钢180 t LF钢液溶解氧为0.002 0%,进行喂硅钙线2 m/t,精炼终点[O]为0.001 5%,2 mm冷轧板夹杂物为C类0.51.0级,主要成分为CaO·Al₂O₃·SiO₂。