Modeling of the nonisothermal kinetics of iron enrichment in hot-dip galvanneal coatings on IF steel sheets

Abstract

The iron content of hot-dip galvanneal coatings, on interstitial free steel, after the nonisothermal treatment was calculated in two ways. First the iron content corresponding to a given holding time in the salt bath was determined from the fitted isothermal curves. Second, taking this iron content as the starting point, the iron enrichment due to air cooling was calculated. Both models were based on the idea that a nonisothermal reaction can be considered to be a series of small steps. The models differed on the mathematical implementation of this idea. Additivity principle proved that the isothermal reactions are isokinetic.