SYMPOSIA PAPER Published: 24 August 2020

Near-Threshold Fatigue Crack Growth Investigation of Ni-Mo-V Steel in Hydrogen Environment


The influence of hydrogen gas (448 kPa) on the near-threshold fatigue crack propagation rates in a 661 MPa yield strength Ni-Mo-V steel was investigated at 24 and 93°C at a testing frequency of 120 Hz. The threshold tests were performed at three load ratios (R = 0.1, 0.5, and 0.8) using a continuously decreasing and increasing stress-intensity technique. Crack growth rates measured in hydrogen were compared with those in air and argon. Data indicated that the rates of near-threshold crack propagation in hydrogen were slower than those in air at stress intensity range values (ΔK) less than 12 MPa·m1/2. In hydrogen, the maximum percentage of intergranular failure occurs at a ΔK of 10 MPa·m1/2, regardless of R ratios and temperatures studied.

Author Information

Liaw, P., K.
Westinghouse Research and Development Center, Pittsburgh, Pa., US
Hudak, S., J.
Southwest Research Institute, San Antonio, Tex., US
Donald, J., K.
Del Research Division, Hellertown, Pa., US
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: E08
Pages: 370–388
DOI: 10.1520/STP791B1983022
ISBN-EB: 978-0-8031-7720-8
ISBN-13: 978-0-8031-0729-8