High temperature gaseous oxidation for passivation of austenitic alloys

摘要

A method for forming a chromium-rich layer on the surface of a nickel alloy workpiece containing chromium includes heating the workpiece to a stable temperature of about 1100° C., and then exposing the workpiece to a gaseous mixture containing water vapor and one or more non-oxidizing gases for a short period of time. The process conditions are compatible with high temperature annealing and can be performed simultaneously with, or in conjunction with, high temperature annealing.