DEFECT CONDEMNATION FOR SUBMARINE PRESSURE HULL WELDS

PDF

Authors
  1. Matthews, J.R.
  2. Porter, J.F.
  3. MacAdam, T.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Abstract
The British standards for submarine pressure hulls indicates the the presence of any lack of fusion defects in the weld is cause for rejection. However, depending upon the size and location of the defect, certain amounts of lack of fusion may be acceptable. Six explosion bulge test panels were welded to have lack of fusion flaws; 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 propagation beyond the limits of the bulge apex. Prior to testing, the welds were examined with manual ultrasonics and computer aided ultrasonics. They were also radiographed at plus and minus 20 degrees to normal (standard radiography would be shot at normal). The NDT was conducted to relate performance back to NDT (as opposed to just defect size and location). Following explosion testing, the welds were sectioned and opened to determine the true defect extent. Defect size and location was found to be less of a determining factor in the quality of the weld than the base properties of the weld and steel. It was found that condemnation criteria should be based on these base properties as well as on the size and location of defects.
Keywords
Computer aided ultrasonics;Lack of fusion;Enhanced radiography;Defect condemnation;Acceptance criteria;Acceptance tests
Report Number
DREA-TM-98-202 — Technical Memorandum
Date of publication
01 Jan 1998
Number of Pages
46
DSTKIM No
98-02418
CANDIS No
509293
Format(s):
Hardcopy;Document Image stored on Optical Disk

Permanent link

Document 1 of 1

Date modified: