Development of Nb2O5|Cu composite as AISI 1020 steel thermal spray coating for protection against corrosion by soil in buried structures [Desenvolvimento e uso do compósito de Nb2O5|cu como revestimento aplicado por aspers?o térmica sobre o a?o aisi 1020 para prote??o contra a corros?o pelo solo em estruturas enterradas]

摘要

An Nb2O|Cu corrosion-resistant coating was developed and applied onto AISI 1020 steel substrate by Powder Flame Spray. A galvanostatic electrochemical technique was employed, with and without ohmic drop, in four different soils (two corrosively aggressive and two less aggressive). Behavior of coatings in different soils was compared using a cathodic hydrogen reduction reaction (equilibrium potential, overvoltage and exchange current density) focusing on the effect of ohmic drop. Results allow recommendation of Nb2O5|Cu composite for use in buried structure protection.