On the in Situ Aluminothermic Reduction of MnO in the Continuous Galvanizing Bath

摘要

The aluminothermic reduction of external oxides within the continuous galvanizing bath has been invoked frequently in the recent literature to partially explain the reactive wetting and formation of an integral Fe-Al layer on the surfaces of selectively oxidized advanced high strength steels. In this mechanism, the bath dissolved Al reacts with and reduces the external oxide, thereby exposing the underlying substrate to the continuous galvanizing bath such that the Fe-Al intermetallic layer forms in the normal manner. This contribution will update the reaction kinetics results of the Galvatech 2011 paper. The limitations of using this reaction to promote reactive wetting are discussed within the context of oxide layer thickness and morphology when galvanizing selectively oxidized substrates. The implications for bath management, Fe-Al interfacial layer formation during galvanizing and inhibition breakdown are also discussed.