Thermodynamic model and mechanism of non-alloyed hydrogen deoxidation of GCr15 bearing steel

ABSTRACT

A new method of non-alloyed hydrogen deoxidation is proposed, and the hydrogen deoxidation of GCr15 is studied using thermodynamic modelling. Deoxidation by blowing hydrogen is dominated by hydrogen molecular, and the degree of deoxidation depends on ${\displaystyle \frac{p_{{\mathrm{H}}_2\mathrm{O}}}{p_{{\mathrm{H}}_2}}}$, which is independent of [H]. Carbon and hydrogen will compete for deoxidation during the blowing of hydrogen. The deoxidation mode depends on the relationship between the actual ${\displaystyle \frac{p_{{\mathrm{H}}_2\mathrm{O}}}{p_{{\mathrm{H}}_2}}}$ and the critical ${\displaystyle \frac{p_{{\mathrm{H}}_2\mathrm{O}}}{p_{{\mathrm{H}}_2}}}$. The system pressure has a great influence on the carbon / hydrogen deoxidation equilibrium. Under vacuum conditions, carbon has a stronger deoxidation ability than hydrogen. Finally, a new process for hydrogen deoxidation was proposed. In the later stage of converter smelting, hydrogen was blown to reduce the excess oxygen → tapping, and hydrogen was blown to alternate deoxidation of carbon and hydrogen → sufficient carbon powder was added into the ladle → RH treatment, and hydrogen was stopped to blown, and carbon deoxidation occurred.

KEYWORDS:

• GCr15 bearing steel
• H₂ deoxidation
• deoxidation thermodynamics
• inclusions
• C deoxidation
• deoxidation kinetics
• competitive deoxygenation
• H2 deoxidation process and mechanism

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Hebei Natural Resources Fund Project of China [grant number E2021417001]; Key R&D Projects in Hebei Province of China [grant number 21311002D]; Scientific Research Projects of Colleges and Universities in Hebei Province [grant number QN2022090].