| 摘要 |
PURPOSE:To improve the quality of a valve by providing a build-up alloy supply device having a heat reflection plate in a specific position with respect to a valve face and disposing a shielding gas supply nozzle having a prescribed shape and size. CONSTITUTION:The build-up alloy supply device 4 having the heat reflection plate 5 is disposed in the position apart by 2-10mm from a valve face part 2 along the face around the peak point 2a of the valve face part. An irradiation part of laser light, i.e., a molten pool part 7 is provided in the position symmetrical with the supply port thereof. The shielding gas supply nozzle 8 having the bore of 1.5-5 times the max. diameter of the pool 7 and the length of >=10 times the bore is disposed in the tangent direction of the face part 2. Build-up welding s executed by the laser light while the shielding gas is supplied at a flow rate of 0.05-1.0m/sec to the neighborhood of the pool 7. The pinholing of the build-up alloy is prevented and the quality of the valve is improved by the above-mentioned method. |
