アキシャル溝型蒸気タービンロータの超音波探傷技術の開発
Development of Ultrasonic Testing Method for Axial Groove Type Steam Turbine Rotor
著者:
鈴木 豊 Yutaka SUZUKI 千葉 弘明 Hiroaki CHIBA 工藤 健 Takeshi KUDOU
発刊日:
公開日:
Axial Groove Type Rotordouble probe techniqueSteam TurbineTip echo techniqueUltrasonic Testing
概要
Refracted angle for UT of axial groove type rotor is limited with the distance of the axial direction from the sensor installation surface. High intensity detection technique changes with the refracted angle, the change may require a combination of multiple inspection techniques. For this reason, detectable distance of a double probe technique and a tip echo technique are examined. In the distance more than 35mm, refracted angle become more than 35 degrees where refracted intensity is high and the defect is detectable using the double probe technique. In the distance of 35mm or less, signal to noise ratio of the tip echo technique becomes greater than two. Therefore combination of these UT techniques make possible to inspect overall distance without the dismantlement of rotor and blade.