The influence of oxygen on the inoculation process of cast iron

The role played by oxygen during the inoculation of cast iron was investiga ted, It was found that oxygen is not desirable when commercial and pure Ca inoculants are employed. Consequently, the cast iron exhibits inferior mech anical strength, with increasing chilling susceptibility and hardness, It i s shown that depending on the degree of oxidation of the molten iron, CaC2, or CaC2-CaO mixtures are formed. The negative effect of oxygen in iron ino culation can be explained by its effect on reducing the likelihood of CaC2 formation. Relatively large contents of oxygen in the inoculated melt lead to a reduced cell count, Hence, under these conditions, high degrees of und ercooling and relatively high chill tendencies are expected during the eute ctic transformation.