On the transition of fatigue crack growth from stage 1 to stage 2 in a corrosive environment

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Metallurgical Transactions, A

DOI:https://doi.org/10.1007/BF02648426· OSTI ID:207698

Hamano, Ryuichi ^[1]

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1. National Research Inst. for Metals, Tsukuba, Ibaraki (Japan)

The growth of a fatigue crack nucleated along the slip bands of persistent slip bands (PSBs) or persistent Luders bands (PLBs) occurs over two successive propagation stages--stage 1 (shear mode) and stage 2 (normal mode). The transition of fatigue crack growth from stage 1 to stage 2 has been investigated in monocrystals and polycrystals as a function of strain amplitude, crystallographic orientation of specimens, slip behavior of planar or wavy slip deformation, and grain boundaries. In the present article, the authors present experimental results suggesting that the transition of fatigue crack growth from stage 1 to stage 2 is accelerated in a hydrogen environment and discuss whether the early transition of the stages of fatigue crack growth is caused by localized deformation or decohesion at a notch root. Fatigue tests were carried out on U-notch specimens of JIS HT80 and SNCM439 (correspondent to AISI 4340) steels in laboratory air and in a 3.5% NaCl aqueous solution at a cathodically polarized potential.

• Sponsoring Organization: USDOE
• OSTI ID: 207698
• Journal Information: Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 2 Vol. 27; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AIR
AQUEOUS SOLUTIONS
CARBON ADDITIONS
CHROMIUM ADDITIONS
COPPER ADDITIONS
CORROSION
CRACK PROPAGATION
CRACKS
DISLOCATIONS
FATIGUE
HYDROGEN
IRON BASE ALLOYS
MANGANESE ALLOYS
MOLYBDENUM ADDITIONS
NICKEL ALLOYS
NUCLEATION
SCANNING ELECTRON MICROSCOPY
SILICON ADDITIONS
SLIP
SODIUM CHLORIDES