Interfacial reactions between glass coatings and steel substrates induced by laser cladding

Abstract

Interfacial reactions between glass and metal have not yet been clarified. On the basis of a composition determination using electron probe microanalysis, the present paper investigates interfacial reactions glass coatings and carbon steel or commercial pure iron substrates induced by laser cladding. The interfacial redox reactions take place between the glass coatings and the substrates at elevated temperatures prevailing in the melt pool under laser irradiation because of the physical chemical property difference between the glass melt and the substrates. As a result,the Fe and C in the substrates are oxidized; the glass constituents Na 2O, K 2O, CaO, SiO 2, Al 2O 3, CoO and NiO are reduced. The glass phase has penetrated into the substrates, especially the carbon steel substrate. This results because the substrates are corroded and dissolved along grain boundaries or into the grain bulk by glass melt during laser cladding.