The Effect of Fabrication Method of Cobalt Base Clad Layer on Air Oxidation

摘要

The paper presents oxidation experiment with clad layers made of the cobalt base powder and prepared by the multi overlapped tracks and sublayers fabricated by means of plasma transferred arc (PTA) and laser cladding technologies. The oxidation processes were carried on at 1100 deg. C for 200 hours. In the course of investigation it was demonstrated that there were no evidence of influence of the fabrication method on the corrosion resistance of cobalt clad layers. The phase compositions of the scale were the same - generally Cr_2O_3 and similar tendency for cracking and spalling. In both cases changes in the layer under the scale also exhibited similar tendency - decomposition of the carbides from the interdendritic regions and severe internal corrosion along the dendrite boundaries.