| 摘要 |
PURPOSE:To prevent a crack from occurring as well as to improve a degree of abrasion resistance ever so better, by depositing a stellite alloy first in a seat part of a valve body material and then depositing a Veganess alloy or a Cormoloy alloy on the topper layer. CONSTITUTION:A corrosion proof, heat resiting Co group alloy, for example, a stellite alloy on the like is deposited on an annular region of a material to form a set surface of a valve body, forming a Co group alloy layer 5. Next, an Ni group alloy excellent in abrasion resistance, for example, a Veganess alloy or a Cormoloy alloy or the like is deposited on top of the Co group alloy layer 5, forming an Ni group alloy layer 6. Deposition of the Ni group alloy layer 6 onto the Co group alloy layer 5 takes place by means of tungsten inert gas welding or plasma spraying. According to this method, the Co group alloy laer works as a buffer material against a crack of the Ni group alloy layer so that any crack due to thermal stress in the Ni group alloy layer is checked, thus such a seat surface as being excellent in abrasion resistance is securable. |
