Evaluation of modern X70 HFERW line pipe. Final report

Technical Report · Fri May 01 00:00:00 EDT 1992

OSTI ID:10169569

Groeneveld, T P ^[1]

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1. Battelle, Columbus, OH (United States)

A 20-inch-diameter by 0.500-inch-wall high-frequency, electric-resistance-welded (HFERW) X70 line pipe was evaluated to assess the strength properties, fracture behavior, thermal stability, and susceptibility to environmentally induced degradation that may affect its behavior in gas transmission service. The steel from which the pipe was produced was processed using advanced steel-making practices that resulted in a low sulfur content and was microalloyed with Cb, V, and Ti. The steel was controlled rolled with 75% of the rolling reduction being accomplished at temperatures below 1,418 F (770 C); the finishing temperature was 1,328 F (720 C) and the steel was hot coiled after finishing. The seam weld was produced by high frequency electric resistance welding and the seam weld region was post-weld normalized. This study has shown that the seam weld region in this X70 pipe was of good quality. No indications of weld line defects were obtained during ultrasonic inspection and the tensile properties of the weld zone met the requirements for X70 line pipe. In addition, the fracture resistance characteristics of the HFERW seam, determined with Charpy V-notch specimens and the weld ductility test specimens, indicated high ductile fracture energy absorption and a transition temperature of approximately {minus}60 F. However, the steel from the pipe body exhibited scatter in the fracture appearance and energy absorption determined with Charpy V-notch specimens; its Charpy 85% SATT was judged to be about {minus}10 F. Overall, the results of the evaluation of this joint of pipe support the claims that high-quality, heavy-walled line pipe can be produced using advanced steel making methods and high-frequency electric resistance welding procedures.

• Research Organization: American Gas Association, Inc., Arlington, VA (United States); Battelle, Columbus, OH (United States)
• Sponsoring Organization: American Gas Association, Inc., Arlington, VA (United States)
• OSTI ID: 10169569
• Report Number(s): AGA-94015613; ON: UN94015613; TRN: AHC29416%%54
• Resource Relation: Other Information: PBD: May 1992
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
03 NATURAL GAS
PIPES
MECHANICAL PROPERTIES
FRACTURE PROPERTIES
THERMODYNAMIC PROPERTIES
CORROSION RESISTANCE
RESISTANCE WELDING
LOW ALLOY STEELS
PIPELINES
WELDED JOINTS
ULTRASONIC TESTING
NATURAL GAS DISTRIBUTION SYSTEMS
MECHANICAL TESTS
STRAIN AGING
TENSILE PROPERTIES
HYDROGEN EMBRITTLEMENT
STRESS CORROSION
EXPERIMENTAL DATA
360100
032000
METALS AND ALLOYS
TRANSPORT, HANDLING, AND STORAGE