PURPOSE: To prevent a torch electrode from being worn during a melting treatment by adhering a pair of sheet materials consisting of high alloy powder having heat resistance and resin binder to a cam surface via a spacing extending in the circumferential direction of the cam in the central part of both and subjecting the same to a melting treatment by means of a TIG arc torch.
CONSTITUTION: Two sheets of the sheets 2 are produced by using the high alloy powder having heat resistance and the resin binder. These sheets are adhered by an adhesive tape of an acrylic resin on the surface of the cam 1 which is a stock W of a cam shaft, apart the prescribed spacing 3 extending in the circumferential direction in the central part of both. This stock W of the cam shaft is subjected to a dewaxing treatment in a gaseous nitrogen atmosphere and is then subjected to the remelting treatment of the high alloy by using the TIG arc torch 4, by which a surface hardened layer is formed on the cam 1. A shielding gas 6 ejected from the arc torch 4 flows along the spacing 3 of the sheet materials 2 and does not reflect in the electrode 4a direction and, therefore, the splashing of the alloy powder and metal vapor to the electrode 4a is obviated and the electrode 4a is not worn at all.
OSAKI SHIGEZO
YOUSHINA NORIO
OUCHI KATSUYA
