04890496 is referenced by 13 patents and cites 3 patents.

A method for detecting hydrogen attack by ultrasound wave velocity measurements in which ultrasound waves (e.g. longitudinal, shear, or creeping) are transmitted from one transducer to another transducer along a fixed path through a steel body such as pipe. The velocity of the ultrasound wave is determined with an accuracy of 0.1 percent from the fixed path length and the time for a wave to travel from one transducer to the other transducer. A decrease in velocity by more than two percent indicates hydrogen attack. In one embodiment, either refracted longitudinal or refracted shear waves are transmitted, and the velocities thereof are determined. In another embodiment, a creeping wave is transmitted from one transducer to the other transducer with the creeping wave including a surface wave and a subsurface wave. Travel time of the subsurface wave is measured and used with the known fixed path length in determining velocity. In the third embodiment ultrasonic waves are transmitted into the material and the backscattered ultrasound is measured. An increase in backscattered ultrasound is related to hydrogen attack.

Title
Method and means for detection of hydrogen attack by ultrasonic wave velocity measurements
Application Number
7/241504
Publication Number
4890496
Application Date
September 7, 1988
Publication Date
January 2, 1990
Inventor
John J Hanley
San Antonio
TX, US
Gary J Hendrix
San Antonio
TX, US
David G Alcazar
San Antonio
TX, US
Anmol S Birring
San Antonio
TX, US
Agent
Flehr Hohbach Test Albritton & Herbert
Assignee
Electric Power Research Institute
CA, US
IPC
G01N 29/04
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