PURPOSE: To form an Al2O3 coating on the surface of a material to be a high temp. corrosion resistant member via an Ni-Al layer by subjecting an Ni alloy base metal coated with an Al alloy layer to annealing in vacuum and heating in an oxidizing atmosphere.
CONSTITUTION: Ni or an alloy occupied with ≥20% Ni is used as a base metal, and the surface of the above sheet or wire is coated with the layer of Al or an Al alloy, which is subjected to annealing in vacuum or in an inert gas and heating in an oxidizing atmosphere to form the coating of Al2O3 on the surface via the layer of intermetallic compound Ni3Al and NiAl. In this way, a member improved in corrosion resistance at a high temp. and chemical resistance, particularly, a heater member can be obtd.
YAMADA HIROSHI
IWANE FUMIO
FUNAO KIKUICHI
