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The effect of weld metal matching on girth weld performance. Volume 1, A general literature review: Final report

Technical Report ·
OSTI ID:6877436
 [1]
  1. Ghent Rijksuiversiteit (Belgium). Lab. Soete

The objective of this report was to examine the assumptions and assess the limitations of currently used fitness-for-purpose based defect assessment methodologies. The focal point of the evaluations was the study of the effect of the relative difference between pipe and weld metal yield strengths on the prediction capability of the PD 6493, WES 2805, API 1104, CSA Z184 and BS 4515 girth weld defect acceptance fitness-for-purpose methods of analysis. The examinations included an evaluation of the weld metal yield strength effects on failure behaviour through sample applications (case studies). The following recommendations were made. The considerable consequential benefits of overmatching weld metal on joint performance should be explored in fitness-for-purpose defect assessment procedures. It is recommended, therefore, to stipulate weld metal yield strength overmatching for preventing the situation where a weak weld valet have to take all the deformation in the event of overloads. Note that this issue is of paramount importance when yielding can no longer be treated as small scale. In this connection, there are two over-riding needs: (a) Provisions should be specified in pipeline codes which address the weld metal matching effects on tolerable defect size predictions. (b) In order to verify whether this property is obtained, the yield strength of the weld deposit in a transverse tensile test should be measured. The ultimate technical benefits to accrue is that girth veld defect assessment procedures can be simplified when veld metal yield strength is specified. Moreover, this would also prevent the specification of high toughness requirements and thus permit a revision of the specified toughness requirements.

Research Organization:
American Gas Association, Inc., Arlington, VA (United States). Pipeline Research Committee; Ghent Rijksuiversiteit (Belgium). Lab. Soete
Sponsoring Organization:
American Gas Association, Inc., Arlington, VA (United States)
OSTI ID:
6877436
Report Number(s):
AGA-93007103; CNN: PR-202-922
Country of Publication:
United States
Language:
English