Finite Difference Kinetics Modeling for Galvanized Steels with Post Heat Treatments

Abstract

Galvanized steels are widely used in construction, electronic, and automotive applications. By applying heat treatment after the hot-dip galvanizing process, zinc and iron in the galvanized coatings are interacted and series of zinc-iron intermetallic phases are developed. Correspondingly, the properties of galvanized steels may be enhanced. In the recent past, attempts have been made to develop kinetics models to help predict the interdiffusion of zinc and iron in the hot-dip and annealing steps, yet they are generally complicated and sometimes do not agree well with the actual data. In this work, we extend the prior works to develop a mathematical model for predicting the interdiffusion of zinc and iron and the growth of intermetallic phases during annealing that is less complicated, yet provides reasonably accurate results, by using an explicit finite difference method (FDM) along with a special treatment at the boundaries of each phase. The data from literatures are compared and discussed to justify the accuracy of the model.