Corrosion resistance of plasma sprayed NiCrAl_(ZrO_2+Y_2O_3) thermal barrier coating on 18-8 steel surface

摘要

The corrosion resistance of NiCrAl+( ZrO_2 + Y_2O_3) thermal barrier coating, formed with the plasma spraying technique, on the 18-8 steel surface was investigated. The phase structure and morphology of the coating were analyzed by means of X-ray diffraction(XRD) and scanning electron microscopy (SEM). The electrochemical corrosion behavior of the coating in 1. 0 mol/L H_2SO_4 solution was studied by using electrochemical measurement methods. The results show that the gradient plasma spraying coating is composed of the NiCrAlY primer coating and the (ZrO_2 + Y_2O_3) top coating, and the coating thickness is 360 μm. The microhardness of coating reaches 1 100 HV. The corrosion resistance of the plasma sprayed coating of the 18-8 steel surface is about 5 times as great as that of the original pattern. The corrosion resistance of the coating is enhanced notably.