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GCr15轴承钢脱氧过程中非金属夹杂物生成热力学及工业实践

赵晓磊1,成 功2,杨华峰1,刘丽娟1,任 英2   

  1. (1.石家庄钢铁有限责任公司 炼钢厂,河北石家庄 053001;2.北京科技大学 冶金与生态工程学院,北京 100083)
  • 接受日期:1900-01-01 出版日期:2020-04-05

Thermodynamics and industrial practice on the formation of non-metallic inclusions in GCr15 bearing steels during deoxidation process

  • Accepted:1900-01-01 Online:2020-04-05

摘要: 通过热力学软件FactSage 7.0和工业实践,对1 873 K下GCr15轴承钢脱氧过程中非金属夹杂物生成热力学进行研究。计算结果表明,当轴承钢中的w(Mg)>0.4×10-6时,钢中夹杂物由Al2O3转变为MgO•Al2O3;当钢中的w(Mg)>10×10-6时,钢中夹杂物主要为MgO。当轴承钢中w(Al)>100×10-6、w(Ca) >0.1×10-6时,钢中开始生成固态CaO•6Al2O3和CaO•2Al2O3夹杂物;当钢中w(Ca)>2×10-6时,钢中生成的夹杂物为液态钙铝酸盐;当钢中w(Ca)>13×10-6时,钢中开始生成固态CaO夹杂物。工业实践检测和热力学计算结果基本吻合,此外,研究发现纯铁液的脱氧热力学与轴承钢差异较大,因此,不能采用纯铁液的脱氧热力学指导轴承钢生产实践。

关键词: 轴承钢, 夹杂物生成, 热力学, 工业实践

Abstract: The thermodynamic software FactSage 7.0 and industrial practice were applied to study the formation of non-metallic inclusions in GCr15 bearing steels during deoxidation process at 1 873 K. Calculated results show that inclusions in molten steel shift Al2O3 to MgO•Al2O3 when the [Mg] mass fraction is larger than 1×10-6. Solid MgO inclusions form when the [Mg] mass fraction is over 10×10-6. Solid CaO•6Al2O3 and CaO•2Al2O3 inclusions generate when the [Al] mass fraction is over 100×10-6 and the [Ca] mass fraction is over 0.1×10-6. Liquid calcium aluminate and solid CaO inclusions appear when the [Ca] mass fraction exceeds 2×10-6 and 13 ×10-6, respectively. Thermodynamic calculated results are in good agreement with measured ones. Besides, evident deviations of deoxidation thermodynamics between pure iron and bearing steel are found, indicating that thermodynamics of pure iron can’t be used to guide the production of bearing steels.

Key words: bearing steel, inclusion formation, thermodynamics, industrial practice