Role of segregated P and S in intergranular stress corrosion cracking of nickel

Conference · Mon Oct 01 04:00:00 EDT 1984

OSTI ID:6277445

Jones, R H; Danielson, M J; Baer, D R

Effect of P and S on the intergranular corrosion and stress corrosion of Ni has been evaluated with corrosion tests, crack tip corrosion modeling and stress corrosion tests and modeling. Corrosion tests were conducted on Ni + P and Ni + S alloys and Ni samples ion implanted with P and S. Results showed that both P and S reduce passivity in Ni and enhance the corrosion rate but that P is oxidized and dissolves in the electrolyte while S remains on the surface. This difference in surface behavior of P and S was used to explain the difference in IGC and IGSCC behavior of Ni + P and Ni + S. The active crevice and crack walls with Ni + S is thought to reduce the concentration gradient and hence the transport of Ni/sup +2/ from tip to mouth which in turn reduces crack tip corrosion rate. By comparison of the geometry, potential dependence and rates of IGC and IGSCC of Ni + P it was concluded that IGSCC was not controlled solely by anodic dissolution but that a mechanical contribution was involved. Strain assisted corrosion was ruled out while a corrosion assisted intergranular fracture process was shown to be feasible.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6277445
• Report Number(s): PNL-SA-12341; CONF-8410208-2; ON: DE85004547
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
AQUEOUS SOLUTIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
CORROSION
CRACKS
DISPERSIONS
ELEMENTS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
INTERGRANULAR CORROSION
ION IMPLANTATION
IONS
METALS
MIXTURES
NICKEL
PHOSPHORUS ADDITIONS
PHOSPHORUS IONS
SOLUTIONS
STRESS CORROSION
SULFUR ADDITIONS
SULFUR IONS
SULFURIC ACID
TRANSITION ELEMENTS