MANUFACTURE OF COMPOSITE PIPE

摘要

PURPOSE:To form a homogeneous ceramic layer in the axial direction of a base pipe in case of forming the ceramic layer on the inside surface of the metallic base pipe by a centrifugal thermit process by mixing a reaction relaxing agent into the thermit agent of the inside surface of the base pipe and also forming an ignition agent layer on the inside surface of a thermit agent layer. CONSTITUTION:The thermit agent layer 2 consisting of the mixture of Al powder and Fe2O3 powder is formed on the inside surface of a metallic base pipe 1 such as a steel pipe. In order to cause slowly the thermit reaction without causing explosively it, the suitable quantity of the endothermic powder of Si compd. such as SiO2 and Si3N4 or metallic oxide such as Al2O3, CuO and TiO2 is mixed into the thermit agent layer 2. The layer 5 of BaO2 and Mg as an ignition agent for the thermit agent is formed on the inside surface of the thermit agent layer 2. While rotating quickly the base pipe, the ignition agent layer 5 is ignited to cause the slow-thermit reaction for the thermit agent layer 2 and an Fe layer 3 and a ceramic layer 4 consisting of Al2O3 plus SiO2 are uniformly formed on the inside surface of the base pipe 1.