Effect of blunt flaws studied in pipeline girth welds
To determine if slag, porosity, or arc strikes significantly contribute to the brittle fracture of pipeline girth welds, NBS analysts developed procedures to test large transverse-weld specimens under low-cycle, fully reversed, strain-controlled fatigue at 28/sup 0/F and at strain levels up to twice the net section yield while maintaining the pipe's curvature. Preliminary results indicate a high tolerance for such flaws in conventional manual and automatic girth welds. The trend of the data suggests that the probability is low for brittle-fracture initiation from blunt flaws under realistic pipeline operating conditions. The tests also revealed that automatic welds may have a higher fatigue resistance than manual welds made with high-hydrogen electrodes.
- Research Organization:
- National Bureau of Standards
- OSTI ID:
- 5666746
- Journal Information:
- Oil Gas J.; (United States), Vol. 79
- Country of Publication:
- United States
- Language:
- English
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