Characteristics of Co-based clad layer formed by laser and TIG cladding

In order to improve the performance of martensitic stainless steel steam turbine blade,pulsed Nd:YAG laser, CO₂ laser,diode laser,and TIG cladding were carried out to deposite Stellite-6 powder on the surface of 12% Cr martensitic stainless steel plate. The shape of cladding layer,dilution, Vickers hardness,dendrite arm spacing (DAS) value,microstructure and wear resistance were investigated with X-ray diffraction, EPMA,EDS and wear test. And the characteristics of different cladding processes were compared. It was found that laser cladding processes, comparing with TIG cladding, have smaller dilution rate,finer microstructure,narrower heat-affected zone,higher Vickers hardness,better wear resistance,higher Co content,and lower Fe content in the resultant cladding layer.