Effect of cathodic potential on corrosion fatigue crack growth rates of a Ni-Cr-Mo-V turbine disc steel in room temperature caustic environment. [Steel-ASTM-471]

Journal Article · Thu May 01 04:00:00 EDT 1980 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02661211· OSTI ID:5380908

Rungta, R ^[1]; Begley, J A

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1. Battelle-Columbus Labs., OH

Corrosion fatigue crack growth rates were measured on compact toughness specimens of ASTM A-471 turbine disc steel in room temperature 12M NaOH solution. The role of cathodic potentials on corrosion fatigue crack growth rates was investigated. Intergranular cracking was observed at cathodic potentials compared to transgranular cracking at open circuit potential and in air. The results suggest a hydrogen embrittlement mechanism of cracking at cathodic potentials. The results suggest that hydrogen diffusion into the material ahead of the crack tip is not rate controlling but is a necessary condition to accelerated cracking. Positive and negative sawtooth wave form results show that environmental effects are accelerated during loading part of the cycle when deformation is occurring. The results have also been analyzed with respect to the linear superposition model proposed by Wei and Landes.

• OSTI ID: 5380908
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 11:5; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360105* -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CORROSION
CORROSIVE EFFECTS
CRACKS
FATIGUE
HYDROGEN COMPOUNDS
HYDROXIDES
MACHINERY
MECHANICAL PROPERTIES
MOLYBDENUM ADDITIONS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
OXYGEN COMPOUNDS
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SURFACES
TURBINES
TURBOMACHINERY
VANADIUM ADDITIONS
VANADIUM ALLOYS