炼钢 ›› 2022, Vol. 38 ›› Issue (6): 14-21.

• 凝固与浇铸 • 上一篇    下一篇

镁处理18Ni350超高强钢中非金属夹杂物析出热力学分析

朱  杰1,刘韶华2,冯胜强3,明  珠3,屈天鹏1,王德永1
  

  1. 1. 苏州大学 沙钢钢铁学院,江苏 苏州 215021;
    2.宁波市镇海减变速机制造有限公司,浙江 宁波 315200;
    3. 中国兵器科学研究院 宁波分院,浙江 宁波 315103
  • 出版日期:2022-12-05 发布日期:2022-12-02

Thermodynamic analysis of non-metallic inclusion precipitation in ultra high strength steel 18Ni350 with magnesium treatment

  • Online:2022-12-05 Published:2022-12-02

摘要: 针对18Ni350钢中非金属夹杂物的形成过程和条件,基于吉布斯自由能最小原理,利用热力学软件FactSage对该钢种特定成分条件下平衡凝固过程及非金属夹杂物析出热力学行为进行了系统分析,研究成分变化对于析出物析出特征的影响规律。同时采用ASPEX和SEM-EDS对镁处理前后试样中的非金属夹杂物的成分、尺寸分布特征进行了检测分析,镁处理前后试样中夹杂物均以Al2O3-Ti2O3系为主,镁处理可以较好地细化试样中夹杂物,夹杂物主要以MgAl2O4为核心,对于复合夹杂物的形成起到了异质形核作用。研究结果对于指导18Ni350钢中非金属夹杂物的形成和控制具有重要的理论指导。

关键词: 夹杂物, 镁处理, 18Ni350钢, 热力学分析

Abstract: In order to analysis the formation of inclusions in 18Ni350 steel, based on the theory of minimum Gibbs free energy, the equilibrium solidification process and the precipitation behavior of the inclusion particles were investigated by using thermodynamics software FactSage under the specific composition. The effect of composition on precipitation process was studied. Meanwhile, ASPEX and SEM-EDS were used to detect the composition and size distribution of inclusions in the samples before and after magnesium treatment. The inclusions in the samples were mainly Al2O3-Ti2O3 series. The inclusions size was refined after magnesium treatment and the inclusions were with MgAl2O4 as core normally. It played a heteronucleation role in the formation of complex inclusions. The results provided important theoretical significance for the formation and control of inclusions in the molten pool of 18Ni350 steel.

Key words: inclusion, Mg-treatment, 18Ni350 steel, thermodynamic analysis