REPAIRING METHOD OF MOLD FOR CONTINUOUS CASTING

PURPOSE:To improve the adhesion of an Ni alloy in the stage of repairing the damaged surface of a copper alloy mold plate for continuous casting by grinding the damaged surface without thoroughly removing the Ni alloy and activating the surface with a strong acid then attaching freshly the Ni alloy thereon. CONSTITUTION:Ni or an Ni alloy is coated on a long side or short side plate made of copper or copper alloy constituting a mold for continuous casting in order to improve the wear resistance thereof. If such coating layer 2 is damaged, the damaged layer is ground as thinly and flatly as possible and thereafter the ground surface is treated with a nitric acid having >=60wt% acid concn., or a strong acid contg. >=50vol% said nitric acid of high concn., or a strong acid contg. >=50vol% nitric acid having >=60wt% acid concn. and consisting of the balance >=1 kinds among sulfuric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, and hydrogen peroxide whereby the ground surface is activated. Ni or an Ni alloy is thereafter plated on said surface. A better effect is obtd. if the Ni or Ni alloy is plated particularly on the inside surface and both surfaces 2 of a short side plate 1 moving between the long side plates.