METHOD FOR JOINING DOUBLE MEMBERS

PURPOSE:To safely execute joining in a short period of time by packing a reacting agent which induces a self-exothermic reaction to an inside tubular member inserted into an outside tubular member, igniting the reacting agent from one end and tightly adhering the joint surfaces of the two members by the reaction heat thereof. CONSTITUTION:An inside pipe 1 and an outside pipe 2 are fitted to each other and are erected in a receiving tray 5. The self-exothermic reacting agent 3 is packed into the inside pipe 1. The self-exothermic reaction is induced and the reaction is vigorously progressed, by which the inside pipe 1 and the outside pipe 2 are joined at the joint surfaces 4 when the reacting agent 3 is ignited from the end thereof. A shielding gas such as Ar is introduced through an introducing hole 6 between the joint surfaces to prevent the oxidation of said surfaces. The inside pipe 1 is expanded larger than the outside pipe 2 and the tight adhesion of the joint surfaces is induced. An insert material may be used for the joint boundary face of the two pipes in order to improve the joining property of the inside pipe 1 and the outside pipe 2. The joining of the double members is thereby easily and safely executed.