A high accuracy ultrasonic measurement method for nondestructive evaluation of residual stress in welded pipings

Book · Tue Aug 01 04:00:00 EDT 1995

OSTI ID:86168

Takahashi, F; Koike, M; Oda, M ^[1]; Mochizuki, M ^[2]

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1. Hitachi, Ltd. (Japan)
2. Hitachi, Ltd., Tsuchiura (Japan)

Today`s nuclear power plants are marked by increasing needs for non-destructive inspection techniques in preventive maintenance programs. Additionally, it is becoming more important to evaluate residual stress which may be a key parameter for crack propagations in welded pipings. The authors have developed an ultrasonic velocity measurement method which obtains ultrasonic velocity changes by residual stress with a high accuracy. The ultrasonic velocity measurement is composed of three procedures. They are as follows. (1) Highly accurate propagation time measurements; (2) Pipe thickness correction; (3) Residual stress evaluation. The ultrasonic velocity measurements have been applied to the residual stress evaluation of carbon steel welded pipings. Destructive testing using stress strain gauges was done after the ultrasonic non-destructive evaluation of the residual stress. The experimental results verified that residual stress in carbon steel welded pipings can be measured by the ultrasonic method within an error of 40MPa, and the non-destructive values are equivalent to the average between inner and outer surface stresses measured by strain gauges.

• OSTI ID: 86168
• Report Number(s): CONF-9505104--; ISBN 0-87170-548-6
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
CARBON STEELS
DATA PROCESSING
EXPERIMENTAL DATA
HEAT AFFECTED ZONE
NUCLEAR POWER PLANTS
PIPES
REACTOR MAINTENANCE
RESIDUAL STRESSES
ULTRASONIC TESTING
WELDED JOINTS