Influence of Initial Iron Content in Zinc Bath on the Dissolution Rate of Iron From Steel During Hot-Dip Galvanizing Process

摘要

Surface quality of automotive steel sheets is more and more strictly controlled especially for the exposed panels. Intermetallic dross particles that form in hot dip galvanizing (HDG) baths are one of the most critical problems affecting surface quality of steel sheets. Even though there are several studies for the thermodynamic phase equilibria of the Zn-Fe-Al ternary system in view of stable and metastable phase diagrams, the kinetic studies for the dissolution of Fe from steel sheets are still insufficient. Therefore, in the present study, we investigated the effect of bath conditions, e.g. initial Fe content on the dissolution rate of Fe from steel sheet using the 'finger rotating method (FRM).' Using FRM, we can estimate the mass transfer coefficient of Fe during dissolution reaction, which is very useful information for predicting the dross formation behavior during HDG processes.