Authors:

R. Ginzel

,

M. Moles

Publication:

Materials Evaluation, Volume 71, Issue 12

Publication Date: 1 December 2013Testing Method:

Ultrasonic Testing

Inspection of shafts, bolts and other long components is challenging, particularly for corrosion. Whether addressing cracking or corrosion, current techniques for inspecting bolts and shafts from the end-faces normally involve calibrating a zero degree beam probe, then scanning round the end-face or head of the bolt to fingerprint it. Interpretation of the results has proved difficult, as signals are reflected from geometry, bolt threads, plus mode conversions occur, as well as reflections from cracks and corrosion. In addition, the usual ultrasonic issues arise: operator variability, no stored data, rough bolt surfaces, inconsistent coupling. This paper describes the approaches for both cracking and corrosion, which are similar in testing procedures, though the analysis differs. Applications are given from three different industries: aerospace, power transmission and offshore oil and gas. The principles of bolt, pin and shaft phased array inspections remain the same, whatever the industry or application. The geometry of the component is more critical.

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