SURFACE HARDENING BUILD-UP WELDING METHOD

PURPOSE:To form a wear resistance and corrosion resistance build-up weld zone on the surface of a base metal, by supplying powder of Cu alloy and powder of hard carbide of metal to an arc between a base metal shielded by inert gas and a non-consumable electrode. CONSTITUTION:When build-up welding the surface of a base metal by a plasma arc welding torch electrode 2, Ar gas 8 as shield gas is jetted from a shield gas nozzle 7, and mixture of powder 6 composed of 20% powder of below 200 mesh of 9% Al-Cu alloy and 80% powder of below 200 mesh of hard carbide such as NbC, VC, TiC etc. is supplied from between an electrode made of Cu water cooled by cooling water 4 and an outer tube 5, and added to a plasma arc formed by Ar gas 9 for forming plasma arc to form a build-up welding layer high in hardness and wear resistance owing to carbide of metal and high in corrosion resistance owing to Cu on the surface of the base metal.