MICROSTRUCTURAL CHANGES OF HOT DIP GALVANIZING FOR CARBON STEEL

Abstract

This article studies the metallurgy of galvanized coatings, the influence of zinc bath temperature and alloying elements on the formation of phases  in hot-dip galvanizing. Carbon steel plates with 20x20x5 mm were surface cleaned, then dipped in a hot-dip zinc bath at different temperatures. The samples were examined using optical microscopy, SEM and measured the composition and thickness of the coatings. The obtained results show that the phases were formed including zeta (ζ), delta (δ), gamma1 (Г1) and gamma (Г) phases. The thickness of the coating was proportional to the galvanizing temperature. The thickness of galvanized coatings was 81μm at 450⁰C and increased to 140μm at 480⁰C, however, it decreased to 107μm at 510⁰C