CERAMIC-SPRAY-COATED STEEL PIPE AND ITS PRODUCTION

PURPOSE:To produce a ceramic-spray-coated steel pipe which is robust and has ornamental beauty by forming a porous film layer of a metal by thermal spraying on the outside surface part of a steel pipe and forming further a ceramic layer thereon by thermal spraying. CONSTITUTION:A porous coating layer of a metal is formed on the surface of a steel pipe to be used as a base metal by plasma, arc or flame spraying of the metal. A metallic oxide which can form ceramics is then thermally sprayed and coated on said layer by a water plasma spraying method to form a porous ceramic coating layer. The metal for the 1st layer includes an Ni-Al alloy, Ni-Cr alloy, stainless steel, etc. and the ceramics for the 2nd layer includes alumina, zirconia, titania, etc. The texture of natural stone is thereby produced on the outside surface of the steel pipe and further an optional pattern is formed thereon by grinding and polishing.