| 摘要 |
PURPOSE:To perform welded overlay perfectly without giving any effect of heat upon base metals by forming a spray-coating film on the surface of copper or copper alloy and locally melting and solidifying the same by a nonconsumable type protected arc welding method. CONSTITUTION:A material provided with heat resistance and abrasion resistance required as a casting mold is spray-coated directly on the inside wall of a mold base metal consisting of copper or copper alloy or on the covering layer having beforehand been formed on the inside wall surface of said base metal and consisting of at least one of iron, nickel or cobalt, whereby a spray-coating film is formed. Only the formed spray-coating film is melted and solidified successively locally by the protected arc heat by a shielding gas using a nonconsumable electrode, whereby an overlay layer is formed. Namely, only the spray-coated film is melted and soldi- fied successively locally along with the movement of the arc welding electrode. In this way, part of the spray-coating material diffuses into the base metal, and the base metal and the overlay layer of the spray-coating material attain the perfectly welded state. |
