IRON-BASED MATERIAL HAVING EXCELLENT OXIDATION RESISTANCE AT ELEVATED TEMPERATUREES AND PROCESS FOR THE PRODUCTION THEREOF

摘要

An iron-based heat-generating material excellent in oxidation resistance at an elevated temperature which comprises an iron-based alloy capable of generating heat by passing electricity therethrough and a coating of aluminum and oxygen formed on the surface of the alloy, the amount of the oxygen in the coating is less than the stoichiometric amount of oxygen in Al2O3. The material can be prepared by vacuum evaporation of Al onto the surface of the iron-based alloy wherein an oxygen partial pressure in a vacuum gaseous atmosphere for the vacuum evaporation is adjusted so that there is formed on the surface of the alloy a coating consisting of aluminum and oxygen, the amount of the oxygen in the coating being less than the stoichiometric amount of oxygen in Al2O3. When the material is heated in ambient or oxidizing atmosphere, an outermost layer of the coating is rapidly converted to Al2O3.