Practical failure analysis

, Volume 2, Issue 2, pp 59–62 | Cite as

An investigation into the failure of API 5L X-46 grade ERW linepipes

  • R. Datta
  • A. Deva
Peer Reviewed Articles

Abstract

The genesis of failure of 6.1 mm thick electric resistance welded (ERW) API 5L X-46 pipes during pretesting at a pressure equivalent to 90% of specified minimum yield strength (SMYS) was investigated. Cracks were found to initiate on the outer surface of the pipes in the fusion zone and propagate along the through-thickness direction. The presence of extensive decarburization and formation of a soft ferrite band within the fusion zone may have contributed to the nucleation of the cracks. Crack propagation was aided by the presence of exogenous inclusions entrapped within the fusion zone. Analysis of these inclusions confirmed the presence of Fe, Si, Ca, and O, indicating slag entrapment to be the most probable culprit.

Keywords

electric resistance welded fusion zone ferrite band API linepipes crack 

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Copyright information

© ASM International - The Materials Information Society 2002

Authors and Affiliations

  • R. Datta
    • 1
  • A. Deva
    • 1
  1. 1.Steel Authority of India LimitedRanchiIndia

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