A study on fatigue strength reduction factor for small diameter socket welded pipe joints
- Ishikawajima-Harima Heavy Industries, Yokohama (Japan)
- Hitachi Ltd. (Japan)
- Mitsubishi Heavy Industries, Takasago (Japan)
- Toshiba Corp., Yokohama (Japan)
- Shibaura Inst. of Tech., Tokyo (Japan)
- Osaka Univ., Ibaraki, Osaka (Japan)
- Japan Power Engineering and Inspection Corp., Minato, Tokyo (Japan)
Factors that may exert influence on the fatigue strength of small diameter socket welded joints of nominal diameter in the 20--50 mm range have been investigated by the fully reversed four-point bending fatigue test with the material, diameter, pipe schedule, throat depth, bead shape, slip-on gap, and root defect as the testing parameters. The fatigue strength of socket joints depended acutely on the diameter. When the diameter is large, the fatigue strength tended to be low and the fracture is of the root-failure mode; when it is small, on the other hand, the fatigue strength is high and the fracture is of the toe-failure mode. Stainless steel proved to be superior to carbon steel; it gave rise to 1.37 times the fatigue strength of the latter for socket joints of nominal diameter 50 mm; the fatigue strength reduction factor determined at 10{sup 7} cycles with respect to the fatigue strength of smooth base metal in the fully reversed fatigue was about 4 for stainless steel and about 5 for carbon steel. The fatigue strength was higher, the larger the Sche number (i.e., the thicker the pipe wall); it was improved markedly by placing one final refinement pass on the toe or by eliminating the slip-on gap. An empirical formula relating the size of the root defect to the fatigue strength reduction has been proposed.
- OSTI ID:
- 404271
- Report Number(s):
- CONF-960706-; ISBN 0-7918-1785-7; TRN: IM9652%%131
- Resource Relation:
- Conference: American Society of Mechanical Engineers (ASME) pressure vessels and piping conference, Montreal (Canada), 21-26 Jul 1996; Other Information: PBD: 1996; Related Information: Is Part Of Pressure vessels and piping codes and standards: Volume 1. PVP-Volume 338; Esselman, T.C. [ed.] [Altran Corp., Boston, MA (United States)]; Adams, T.M. [ed.] [Stevenson and Associates, Cleveland, OH (United States)]; Bhavnani, D. [ed.] [Public Service Electric and Gas Co., Hancock`s Bridge, NJ (United States)]; Cofie, N.G. [ed.] [Structural Integrity Associates, Inc., San Jose, CA (United States)]; Jones, D.P. [ed.] [Westinghouse Electric Corp., West Mifflin, PA (United States)]; Olson, D.E. [ed.] [Sargent and Lundy, Chicago, IL (United States)]; Thailer, H.J. [ed.] [Pacific Gas and Electric Co., San Francisco, CA (United States)]; PB: 295 p.
- Country of Publication:
- United States
- Language:
- English
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