Effect of Silicon on Corrosion of Directional Fe-B-Si Alloy in Liquid Zinc

The effect of Si on the corrosion of an Fe-B-Si alloy in liquid zinc was investigated. Corrosion tests of Fe-B-Si were conducted in a pure zinc bath (99.99 wt pct Zn). The results indicated that Si in α-Fe phase had a significant effect on the structure and evolution of corrosion interfaces in a directional Fe-B-Si alloy immersed in liquid zinc. Moreover, Si enrichment of the corroded interface induced changes in the mode of element diffusion, thereby affecting the Fe-Zn reaction and the quantity and volume of Fe-Zn compound. The Fe-Zn compound was occluded with the residual Fe 2 B closest to the corrosion interface, this structure could prevent direct contact between the liquid zinc and the alloy, and firm rooting of the compound at the interface. Therefore, Si in α-Fe phase had a significant effect on the corrosion resistance of Fe-B-Si alloy in liquid zinc. At a Si content of 0.318 wt pct, the densest composite corrosion product layer and highest corrosion resistance were obtained.