| 摘要 |
PROBLEM TO BE SOLVED: To provide an evaluation method of creep damage, capable of evaluating accurately the degree of the creep damage, directly under the surface of a weld zone by a very simple method and using a lo-cost device. SOLUTION: This evaluation method of creep damage for evaluating the degree of the creep damage on a weld zone after welding a welding material on a base material includes features, wherein an ultrasonic wave from a vertical probe is irradiated to the welding zone; a reflected echo from the bottom surface is repeatedly received; an attenuation factor Db is determined by using a height B1 of the reflected echo the first time, a height B2 of the reflected echo in the second time, a plate thickness W1 of the welding material, and a distance W2 from a plate thickness origin, when the reflected echo in the second time is emitted; the attenuation factor Db is calculated using the equation: Db=20(log(B1/B2))/(W2-W1); and the creep damage of the weld zone are determined based on the attenuation factor Db. COPYRIGHT: (C)2009,JPO&INPIT
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