MEMBER FOR MOLTEN METAL BATH PROVIDED WITH COMPOSITE SPRAYED COATING HAVING EXCELLENT CORROSION RESISTANCE AND PEELING RESISTANCE AGAINST MOLTEN METAL

摘要

PROBLEM TO BE SOLVED: To obtain a member for a hot dip metal bath having coating excellent in corrosion resistance to hot dip metal and peeling resistance by forming a cermet sprayed coating substrate layer composed of specified ratios of metallic boride, metallic carbide, Co or the like and a ceramics sprayed coating surface layer composed of MgO, Al₂O₃ or the like on the surface of a base material. ;SOLUTION: On the surface of a base material, a cermet sprayed coating substrate layer (with 20 to 500 μm thickness) composed of metallic boride (such as WB) by 5 to 60 wt.%, one or more kinds among Co, Cr, Mo and W by 5 to wt.%, and the balance metallic carbide (such as WC) with inevitable impurities is formed. On this substrate layer, a ceramics sprayed coating surface layer (with 5 to 500 μm thickness) composed of A-B type oxide obtd. by combining one or more kinds of MgO and CaO (A group components) and one or more kinds among Al₂O₃ SiO₂, ZrO₂ and Ta₂O₅ (B group components) is formed. Furthermore, in the case this composite srayed coating is subjected to sealing treatment with an inorganic sealing agent (such as a soln. of chromic acid), the penetrating resistance of hot dip metal in the sprayed coating improves.;COPYRIGHT: (C)1998,JPO