Formation of the oxide films on Inconel 718 for the IVHM grapple assembly

The objective of this test was to determine conditions for producing an iridescent colored oxide on Inconel 718 parts within a very limited schedule. The goal was to develop a process that would be compatible with the normal precipitation hardening treatment and, at the same time, produce a satisfactory film on surfaces that have been machined after precipitation hardening. Conditions for producing the film could not degrade the hardness of the Inconel 718. The purpose of the oxide was to reduce the possibility of wear and galling on bearing surfaces of the In-Vessel Handling Machine (IVHM) grapple mechanism during its pre-operational acceptance test