Effects of weld defects at root on rotating bending fatigue strength of small diameter socket welded pipe joints
- Ishikawajima-Harima Heavy Industries, Yokohama (Japan). Production Engineering Center
- Toshiba Corp., Yokohama (Japan). Nuclear Energy Div.
- Shibaura Inst. of Tech., Tokyo (Japan). Dept. of Mechanical Engineering
- Osaka Univ. (Japan). Welding Research Inst.
- JAPEIC, Tokyo (Japan). Welding Engineering Dept.
Rotating bending fatigue tests were conducted on socket welded joints of a nominal diameter 20 mm, and effects of root defect and other various factors, including post-weld heat treatment (PWHT), pipe wall thickness, and socket wall thickness, were investigated. The socket joints exhibited, in the rotating bending fatigue mode, fatigue strengths that were markedly lower than the same 20 mm diameter joints in four-point bending fatigue. Also, where the latter specimens failed always at the toe, root-failures occurred in rotating bending fatigue. When PWHT`d, however, the fatigue strength showed a remarkable improvement, while the failure site reverted to toe. Thicker pipe walls and socket walls gave rise to higher fatigue strength. A formula relating the size of root defects to the fatigue strength reduction has been proposed.
- OSTI ID:
- 404270
- Report Number(s):
- CONF-960706--; ISBN 0-7918-1785-7
- Country of Publication:
- United States
- Language:
- English
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