Laser-surface-alloying of the iron based superalloy incoloy-800H with Al

Abstract

Laser surface alloying by the powder feed method of the iron based superalloy Incoloy 800H with aluminium has been earned out. The effects of different preparation parameters, like laser scan speed and powder feed rate, on the morphology of the alloyed zone have been investigated. Microstructure and composition have been determined by scanning electron microscopy (SEM), optical microscopy, and x-ray fluorescence spectroscopy. Three different phases with different Al-content have been distinguished. The observed Al-enrichment at the surface, the presence of Ni-Al and Fe-Al intermetallic compounds, and the considerable grain refining of the alloyed zone with respect to the substrate, make this furface modification technique a very good method to improve the corrosion behaviour of the Incoloy 800H superalloy.