角鋼片表面疵の自動超音波探傷

抄録

The new automatic ultrasonic inspection system using the surface wave technigue has been developed for the detection of surface and sub-surface flaws of square billets. The high speed and reliable inspection is performed with this system. This paper describes the basic and on-line experimental results of the technique and the outline of the system. The system has been installed at Kokura Steel Works of Sumitomo Metal Industries Ltd.
The following results are obtained from the experiments.
(1) More than 95 percent natural surface defects deeper than 0.5 mm can be detected.
(2) It is observed experimentally that the sub-surface flaw of 1.5 λ (λ : wave length) in depth from the surface can be detected by the surface wave technique.