ULTRASONIC INSPECTION OF SUBMARINE STEEL WELDMENTS
A laboratory investigation was undertaken to develop ultrasonic inspection techniques and, concurrently, to establish tentative acceptance standards for butt weldments in ship plate which would be approximately equivalent to the standards established for radiographic inspection. Butt weldments containing defects of porosity, cracks, inclusions, lack of penetration, and flawless control weldments were prepared in 1-in.-thick HY-80 (80,000-psi yield strength) steel. These weldments were inspected by both ultrasonic and radiographic methods. The ultrasonic inspection was performed by scanning the weld metal and adjacent heat affected zone with a 3/8-in.-diameter 2.25-mc 45 deg anglebeam search unit. Instrument-sensitivity and flaw- acceptance levels were established with reference to a 1/16-in.diameter 1/2-in.- deep hole in a 1-in.-thick HY-80 steel plate. The ultrasonic acceptance- rejection standard was established at a level of instrument sensitivity which would reject those cracks rejected by radiography. Since inclusions and porosity have lower reflective power than cracks, an ultrasonic standard sensitive enough to reject cracks of the size rejected by radiography would not reject inclusions and porosity of a size considered rejectable by radiography standards. Separate standards could not be established for each type of defect, however, since it was impossible to determine reliably the type of flaw from the pattern of the ultrasonic signal with confidence. (auth)
- Research Organization:
- Electric Boat Co., Groton, Conn.
- NSA Number:
- NSA-15-009480
- OSTI ID:
- 4097943
- Journal Information:
- Nondestructive Testing, Journal Name: Nondestructive Testing Vol. Vol: 19
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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