| 摘要 |
PURPOSE:To prevent the formation of crack due to stress corrosion, by shaping the inclination of a zirconium alloy at the angles of 0-5 deg.. CONSTITUTION:When Q value (Q value is shown in an expression Q=[(WII- WI)/WII]/[(DII-DI/DII] if an inner diameter of a covered pipe before rolling is DI and the thickness WII and an inner diameter of the pipe after rolling is DII and the thickness WI) is increased in a rolling process of the covered pipe, stress maximally accumulates over an extent that angles, of which a central axis of a dense hexagonal crystal, the crystalline structure of zirconium, forms to an axis of coordinates in the radial direction of the covered pipe, are 0-5 deg. in a plane containing the inclination of a zirconium alloy, an axis is coordinates in the radial direction of the covered pipe, and an axis of coordinates in the circumferential direction that crosses at right angles with the inclination, thus preventing crack due to stress corrosion. |
