摘要 |
A microstructure form of a welding area is quickly and accurately (or clearly) imaged in a nondestructive inspection. Specifically, while a cross section of a test object S orthogonal to a welding direction is being scanned with an ultrasonic beam B, a reflected signal from the inside of the test object is received. On the basis of the received reflected signal, the scanned cross section is imaged to inspect a microstructure of a welding area 2. In imaging the welding area, a reflected wave from the microstructure of the welding area is enhanced by scanning a cross section of the test object orthogonal to the welding direction with a focused ultrasonic beam at a plurality of different positions in the welding direction, imaging the scanned cross sections on the basis of the resulting ultrasonic received signals, superimposing a plurality of images obtained by scanning at the plurality of positions in the welding direction, and retaining a maximal value of superimposed pixels. |