Predicting initiation of crack growth under stress corrosion cracking conditions

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6247797

Ranjan, R; Buck, O

Under stress corrosion conditions, the major portion of the useful life of a structure is spent in initiation and growth of microcracks, often referred to as the incubation period. Although this period can be a very large fraction of the total time to failure, the prediction of the remaining life of the component during this period is very difficult since there is still a lack of understanding of the processes involved in incubation. To overcome these difficulties, a physical model was developed which, at the present time, is specific to stress corrosion cracking of Cu-30 Zn brass in a nontarnishing ammoniacal solution. The predictions of the model in terms of time to initiation have been tested using experimental data of the effects of applied potential on crack initiation. Coupling of simple nondestructive testing techniques with metallographic observations and scanning electron microscopy provided information on the transition from corrosion pitting to microcrack initiation. Implications of this research on nondestructive evaluation of a component under stress corrosion conditions are discussed.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6247797
• Report Number(s): IS-M-550; CONF-851125-20; ON: DE85015515
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
AMMONIUM COMPOUNDS
BRASS
CHEMICAL REACTIONS
COPPER ALLOYS
COPPER BASE ALLOYS
CORROSION
CRACK PROPAGATION
DISPERSIONS
MIXTURES
SOLUTIONS
STRESS CORROSION
ZINC ALLOYS