Advances in Manufacturing ›› 2019, Vol. 7 ›› Issue (4): 438-447.doi: 10.1007/s40436-019-00266-1

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Study on the modification of inclusions by Ca treatment in GCr18Mo bearing steel

Hong-Yan Zheng, Shu-Qiang Guo, Meng-Ran Qiao, Li-Bin Qin, Xiu-Jing Zou, Zhong-Ming Ren   

  1. State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferrometallurgy and School of Materials Science and Engineering, Shanghai University, Shanghai 200444, People's Republic of China
  • Received:2019-01-22 Revised:2019-05-08 Online:2019-12-25 Published:2019-12-26
  • Contact: Shu-Qiang Guo E-mail:sqguo@shu.edu.cn
  • Supported by:
    This study was financially supported by the Shanghai University and the Joint Funds of the National Natural Science Foundation of China (Grant No. U1560202).

Abstract: The effect of Ca treatment on the modification of inclusions in Al-killed GCr18Mo bearing steel was studied and a thermodynamic and kinetic model was established. The experimental results showed that oxygen content in the steel could be reduced from 120 μg/g to the range 5.5-21.6 μg/g by Al-Ca complex deoxidization at 1 873 K. An appropriate increase in Ca/Al mass ratio is beneficial to reduce the total oxygen content in steel. When the content of dissolved aluminum was in the range of 0.03%-0.3%, with the increase of Ca/Al mass ratio from 0.8-1.6 to 2.4-3.2, the number of inclusions per unit area significantly reduced. In addition, the main types of inclusions were modified from large-sized Al2O3 clusters to plastic or semiplastic liquid phase calcium aluminates. The experimental results matched well with the thermodynamic analysis.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-019-00266-1

Key words: GCr18Mo bearing steel, Ca treatment, Inclusion modification, Deoxidization, Thermodynamics