| Popis: |
For many years it seemed both convenient and accurate to ignore metallurgical texture in carrying out practical non-destructive testing. That this was a false simplification was shown up dramatically in recent studies of the austenitic weld. Large variations in ultrasonic attenuation were encountered in these welds which are now ascribed almost entirely to the effects of texture. These observations reopen the question of texture effects in other materials, such as rolled steel plate, which are known to have modest degrees of grain alignment. Is it still possible to assume that these materials are isotropic without introducing significant errors? The author considers the theory of ultrasonic propagation in textured materials and compares this with the experimental evidence. In addition, another problem where the effects of texture mask the more important effect of stress is mentioned. These discussions pay regard to work on practical, in addition to laboratory, specimens. |
