Application of new experimental methods to pipeline stress corrosion cracking. Annual report, March 1992-February 1993

Technical Report · Thu Apr 01 04:00:00 EST 1993

OSTI ID:5994552

Schmidt, C G; Kobayashi, T; Becker, C H; Pound, B G; Simons, J W

The objective of the investigation is to develop a physically based understanding of the mechanisms of stress corrosion cracking (SCC) in pipeline steels by applying advanced fracture surface and electrochemical characterization techniques to samples taken from fielded pipeline. The investigations found that the effect of pressure fluctuations on the propagation of stress corrosion cracks was readily evident from an analysis of the topographies of conjugate fracture surfaces. Substantial crack blunting was produced under normal pipeline operating conditions. Corrosion deposits were removed from the fracture surfaces of a stress corrosion crack in a pipeline specimen recovered from service. The topography of the underlying metal surface appears to be preserved with little corrosion damage after crack formation. This allowed the cracking process to be reconstructed from the surface topography. In some cases, deposits on the fracture surfaces of stress corrosion cracks contain significant concentrations of metallic elements that are not found in pipeline steels but are likely to be commonplace in the surrounding environment.

• Research Organization: SRI International, Menlo Park, CA (United States)
• OSTI ID: 5994552
• Report Number(s): PB-93-220978/XAB; CNN: GRI-5091-260-2119
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
CHEMICAL REACTIONS
CORROSION
CRACK PROPAGATION
ELECTROCHEMICAL CORROSION
FRACTOGRAPHY
FRACTURE MECHANICS
INTERGRANULAR CORROSION
IRON ALLOYS
IRON BASE ALLOYS
MECHANICS
PIPELINES
STEELS
STRESS CORROSION
SURFACE PROPERTIES