Abstract: Tire cord steel requires good drawing performance,and one of the main factors affecting its drawing performance is non-metallic inclusions in steel.The main source of non-metallic inclusions in steel is deoxidation reaction of molten steel.In order to control non-metallic inclusions in tire cord steel better,the deoxidation thermodynamics should be understood deeply.However,the already published deoxidation thermodynamics of pure iron cannot guide the industrial production practice,and the deoxidation thermodynamics of the molten steel of actual steel grades has not been systematized at present,which needs further study.In the current work,the deoxidation thermodynamics of tire cord steel was calculated and compared with that in pure iron.It was found that there are obvious differences between the deoxidization equilibrium curves under the composition of tire cord steel and that in pure iron.Since there are several alloy elements inevitably exist in the actual production process of tire cord steel,the deoxidization equilibrium curve under the composition of tire cord steel can more accurately guide the control of deoxidization and nonmetallic inclusions in the actual production process of tire cord steel than that under the condition of pure iron.

Key words: tire cord steel, pure iron, deoxidation, non-metallic inclusion, thermodynamic