Prediction of surface oxidation weight gain on 7.8 wt% Cr-containing stainless steel electrode during electroslag remelting.

The surface oxidation weight gains on 7.8 wt% Cr-containing stainless steel at different temperatures were studied by thermogravimetric analysis and scanning electron microscope (SEM) equipped with energy-dispersive spectroscopy (EDS). The results show that there are two layers of oxide scales covering the surface of steel matrix after 100 min high-temperature oxidation. The inner oxide scale consists of (Fe, Cr) oxide and the outer oxide scale is composed of Fe oxide due to the stronger affinity of Cr with O. The growth of outer oxide scale is dominated by the combined effects of chemical reaction rate and mass transfer. Based on the study of the oxidation kinetics at different temperatures, a prediction model for surface oxidation weight gain on 7.8 wt% Cr-containing stainless steel electrode during electroslag remelting is acquired, providing a reference for the determination of the amount of deoxidiser added into the molten slag during electrode remelting. [ABSTRACT FROM AUTHOR]