Influence of steel gauge on the microstructure and corrosion performance of zinc alloy coated steels

• DOI: 10.1016/j.corsci.2010.02.032
• Publication Date: 2010-02-17T09:17:06Z
• Authors: James Sullivan; Chris Weirman; Jon Kennedy; David Penney
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; 620

Abstract Zn–4.8 wt% Al coated steels exhibited a polynomial increase in Zn loss from the cut edge with increasing steel gauge for weight loss and SVET Zn loss in 0.1% NaCl in contrast to a linear increase observed for hot dipped galvanised (HDG) steels. Increasing steel gauge decreased nucleation and increased growth of Zn dendrites for Zn–4.8 wt% Al coated steels. SVET data showed larger Zn dendrites associated with thicker gauges produced more damaging anodes than small dendrites on thinner samples. A polynomial relationship was observed between dendrite size and Zn loss suggesting that microstructure influenced Zn loss in unison with the increased cathodic activity on thicker steels.