Behaviour of laser treated Cr, Ni coatings in the oxidative atmosphere of a steam boiler

This paper summarises the results for a study of laser treated Cr-Ni base coatings under the oxidative atmosphere of steam boilers with 3-3.5 vol.% of free oxygen at 773 and 1073 K. The total oxidation process has been measured by sample weighing. The oxidised layers were examined by scanning electron microscopy (SEM) with an energy dispersive spectrometer (EDS) and wavelength dispersive spectrometer (WDS). The results were compared with the previously measured oxidation results of some Cr-Ni plasma-sprayed coatings and AISI 304 stainless steel. The significant superior oxidation resistance of the laser treated coating to that of the uncoated AISI 304 and the same plasma-sprayed coating is ascribed to a coating without pores and the formation of a thin oxidised protective film. (c) 2004 Elsevier B.V. All rights reserved.