THE EFFECT OF MICROSTRUCTURE ON THE HYDROGEN-ASSISTED FATIGUE OF PIPELINE STEELS

Published

July 14, 2013

Author(s)

Andrew J. Slifka, Elizabeth S. Drexler, Robert L. Amaro, Damian S. Lauria, April Stevenson, Douglas G. Stalheim, Louis E. Hayden

Abstract

Tests on the fatigue crack growth rate were conducted on four pipeline steels, two of grade API 5L- X52 and two API 5L-X70. One X52 material was from the mid 1960s and the other was manufactured in 2011. The two X70 materials had a similar vintage and chemistry, but the microstructure differs. The fatigue tests were performed at 5.5 and 34 MPa pressurized hydrogen gas, at 1 Hz and (load ratio) R=0.5. At high pressures of hydrogen and high values of the stress intensity range (ΔK) there is no difference in the fatigue crack growth rates (da/dN), regardless of strength or microstructure. At low values of ΔK, however, significant differences in the da/dN are observed. The older X52 material has a ferrite-pearlite microstructure; whereas, the modern X52 has a mixture of polygonal and acicular ferrites. The X70 materials are both predominantly polygonal ferrite, but one has small amounts (~5%) of upper bainite, and the other has small amounts of pearlite (

Proceedings Title

Proceedings of the 2013 ASME Pressure Vessels and Piping Division Conference

Conference Dates

July 8-12, 2013

Conference Location

Paris

Pub Type

Conferences

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DOI Link

Keywords

fatigue, hydrogen, hydrogen embrittlement, microstructure, pipeline steel, X52, X70

Citation

Slifka, A. , Drexler, E. , Amaro, R. , Lauria, D. , Stevenson, A. , Stalheim, D. and Hayden, L. (2013), THE EFFECT OF MICROSTRUCTURE ON THE HYDROGEN-ASSISTED FATIGUE OF PIPELINE STEELS, Proceedings of the 2013 ASME Pressure Vessels and Piping Division Conference, Paris, -1, [online], https://doi.org/10.1115/PVP2013-97217 (Accessed December 4, 2024)