Mechanical Properties and Crack Behavior in Line Pipe Steels

The objective of the proposed research is to provide critical standard test methods and data for improving pipeline integrity and speeding the evaluation of new pipeline designs or in-service failures. This objective will be approached by a combination of the following work: (1) Develop axial orientation fatigue data for comparison with the girth data; (2) Evaluate the effects of hydrogen on pipe fatigue and fracture properties; (2) Extend Crack Tip Opening Angle (CTOA) work to include girth direction data, effects of dynamic rates on CTOA, and modeling of CTOA; (3) Examine fracture surfaces to document and evaluate failure mechanisms; (4) Provide baseline data and method to define yield strength of high strength pipeline steels and their welds; and (5) Transfer knowledge and data to codes and standards bodies. 09/05/2008 introduced one additional task to the original agreement and extended the period of performance: To use third party material testing at National Institute of Standards and Technology (NIST) to provide critical fatigue test data for comparison with the girth data, determine the accuracy of existing models (finite element analysis and other engineering models) to assist with the prediction of full-scale results, and identify requirements for next generation model developments that will be used to determine tensile strain limits for pipeline designed using strain-based methods under OTA DTPH56-06-T-000014 "Validation and Documentation of Tensile Strain Limit Design Models for Pipelines." NIST will include saw-cutting, grinding, machining and notching for 40 single-edge notch tensile testing (SEN(T)) specimens. The prepared specimens will be pre-cracked and tested at temperatures ranging from ambient to -60 degrees celsius. Tests will be conducted over a period of 24 months as needed and analyzed data will be provided to the DTPH56-06-T-000014 (Project No 200) collaborators for input into their design models.

  • Supplemental Notes:
    • Program Information: Pipeline Safety Research


  • English


  • Status: Active
  • Sponsor Organizations:

    Pipeline and Hazardous Materials Safety Administration

    U.S. Department of Transportation
    East Building, 2nd Floor 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Performing Organizations:

    National Institute of Standards and Technology

    Technical Analysis Division
    Gaithersburg, MD  United States  20760
  • Principal Investigators:

    Stewart, Tom

  • Start Date: 20120510
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 31220

Subject/Index Terms

Filing Info

  • Accession Number: 01465012
  • Record Type: Research project
  • Source Agency: Department of Transportation
  • Files: RiP, USDOT
  • Created Date: Jan 3 2013 2:54PM