SURFACE TREATMENT METHOD FOR MATERIAL OF MELTING PART FOR WASTE COMBUSTION ASH

摘要

PROBLEM TO BE SOLVED: To improve a durability for a heat cycle upon start and stop of an incinerator when the surface of a heat resistant material of a melting part in the inner surface of a melting furnace is coated with a highly corrosion- resistant coating in the furnace in which ash generated by burning a combustion material including waste is heated into a molten slag. SOLUTION: The surface of the outermost layer of the heat resistant material of the melting part in the inner surface of the melting furnace in which the ash obtained by burning the waste is heated into the molten slag is coated with a spinel type compound MCr2O4 (M is Mg or divalent Fe) with a high corrosion resistance, or a mixed material composed of this compound and chromia and zirconia and an intermediate layer having an intermediate composition of a coating material and a base material is formed in a part between the base material and the coating of the outermost layer. Since the intermediate layer is formed so that thermal expansion characteristics gradually change, a thermal stress due to a heat cycle is decreased so that the coating composed of a plurality of layers hardly generating a peeling can be formed.