Cobalt Base Clad Layer Resistance on the Corrosion under Low Sulfur Pressure

Abstract

The paper considers the sulphidation of the clad layers made of the cobalt base powder and prepared by the multi-overlapped tracks and sublayers fabricated using laser cladding process applied at 800°C under sulphur partial pressure ps2= 10e-8 atm and ps2= 10e-10 atm for 24 hours. The phase compositions of the scale were different. In both cases changes in the layer under the scale exhibited similar tendency – decomposition of the carbides from the interdendritic regions and severe internal corrosion along the dendrite boundaries.