| 摘要 |
PURPOSE:To prevent deterioration in the corrosion resistance of a valve accompanying padding welding by welding machined cast parts to a machined valve seat and a valve body and finishing a valve seat surface and a valve body surface. CONSTITUTION:When a valve seat for, for example, a globe valve made of austenite steel, groove work 8 of the valve seat is carried out firstly for a valve seat blank material. A padding part, on the other hand, is manufactured by casting corrosion-resisting, wear-resisting alloy such as stellite to obtain a casting close to a final shape, which is grounded at a stage 9. This alloy is jointed with the valve seat by electron beam or laser beam welding 10 and the valve seat surface is finished by polishing 11 lastly to obtain the valve seat. This method prevents the base material from having a heat cycle and reduces heat input, so the corrosion of the base material is prevented from deteriorting. |
