FUTURE TREATMENT OF WELD ACCEPTANCE: THE SIGNIFICANCE OF INCOMPLETE FUSION DISCONTINUITIES IN LOW STRUCTURAL TRANSITION TEMPERATURE GMAW WELDMENTS

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Authors
  1. Matthews, J.R.
  2. Hyatt, C.V.
  3. Porter, J.F.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Abstract
The welding acceptance standards for naval ships and submarine pressure hulls indicates that the presence of any incomplete fusion discontinuities in the welds is cause for rejection. In this paper, it is suggested, depending upon the size and location of the discontinuity and the weldment structural transition performance, that certain amounts of incomplete fusion are acceptable. In short, weldmetal tearing resistance, often overrides the weld discontinuity's influence on weldment failure. In our study, six explosion bulge panels were welded to have severe incomplete fusion flaws in weldments which otherwise exhibited low structural transition temperature performance; two panels had root flaws and the other four had cap flaws. Explosion bulge tests were performed to determine if the welds could resist crack extension beyond the limits of the bulge apex. Prior to explosion testing, the welds were examined with manual ultrasonics and computer-aided ultrasonics. They were also radiographed at plus and minus twenty degrees to normal (standard radiography would be shot at normal). The NDT was conducted to relate performance back to NDT (as opposed to just discontinuity size, nature, and location). Following explosion testing, the welds were sectioned and opened to determine the true discontinuity nature and size, and the degree and nature of extension under explosive loading. TRUNCATED
Date of publication
01 Jun 1998
Number of Pages
32
DSTKIM No
98-01877
CANDIS No
508508
Format(s):
Hardcopy;Document Image stored on Optical Disk

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