Thermite fusion welding is a welding method which uses the heat of chemical reaction as a heat source. Welding method using chemical reaction heat as heat source. When welding, the ends of two workpieces to be welded are fixed in the mold in advance, and then the mixture of aluminum powder and iron oxide powder (called thermite) is heated in the crucible, so that it undergoes exothermic reduction reaction, becomes liquid metal (iron) and slag, and is injected into the mold. Liquid metal flows into the joint gap to form weld metal, while slag floats on the surface.
Preparation of thermite fusion welding
(1) Before each start, bake and dry the mold with a heating tool (blowtorch or drying oven) to drive away moisture.
(2) Clean the mold after each use, and use a soft brush or other soft items to avoid damaging the mold.
(3) Check the tightness of the contact surface of the mold to prevent copper liquid from leaking from the gap during operation.
(4) The mold fixture is used to open and close the mold, and the tightness of the mold fixture has an influence on the welding effect. Please carefully check the mold fixture before welding and make appropriate adjustments.
(5) The mold is made of graphite, which is fragile and can't stand throwing and strong impact. Therefore, it is not allowed to forcibly put the weldment exceeding the mold size into the mold, or to remove the residue with hard objects and tools.