Recent developments in ultrasonic nondestructive evaluation in Japan

Abstract

Ultrasonic nondestructive evaluation is one of the most powerful tools among many nondestructive evaluation procedures and plays an important role in the on-line manufacturing process and postprocess material testing. Recent developments in this field in Japan at universities, government laboratories, and industrial laboratories are surveyed. The behavior of ultrasonic waves in solids is vividly understood by both computer simulation and stroboscopic photoelastic visualization and it provides a fundamental basis of quantitative information for sizing flaws. The acoustoelastic measurement of residual stress in structural components allows us to estimate their service-life expectancy. By the acoustoelastic evaluation of texture in steel, an ultrasonic pole figure is obtained more conveniently than with the x-ray method. As industrial applications, there are the laser generation and detection of ultrasonic waves, the detection of surface defects and internal voids in ceramics, phased array transducers and their application for steel pipe testing, and on-line wall thickness measurements using an electromagnetic acoustic transducer for hot seamless steel pipes. The acoustic microscope also has many applications in the nondestructive evaluation of materials.