| 摘要 |
PURPOSE:To prevent the stress corrosion crack of a stretch tube by a method wherein the sectional configuration of the corner between a flange part and the outer peripheral surface of the stretch tube is formed so as to have an arc having a radius of 7mm. or more. CONSTITUTION:The stretch tube 6 is formed by a corrosion-resistant steel material such as Inconel 600 or the like, for example, and this material is corner of the used after a solution treatment without applying a cold working. The lower surface and the outer peripheral surface of the flange part 13 of the stretch tube is formed so as to have the arc having a radius of 7mm. or more in the section thereof. According to this method, a remaining stress will never be existing in the stretch tube and, theefore, the generation of the stress corrosion crack may be prevented. |
