Evaluation of toughness deterioration by an electrochemical method in an isothermally-aged N-containing austenitic stainless steel

Journal Article · Sat Feb 14 23:00:00 EST 2009 · Materials Characterization

DOI:https://doi.org/10.1016/j.matchar.2008.07.007· OSTI ID:21192596

Lopez-Hirata, Victor M; Avila-Davila, Erika O; Melo-Maximo, Dulce V ^[1]

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1. Instituto Politecnico Nacional (ESIQIE), Apartado Postal 118-556, Admon. GAM, Mexico, D.F. 07051 (Mexico)

This work presents the results of an evaluation of the deterioration of cryogenic toughness by means of an electrochemical method in a N-containing austenitic stainless steel (JK2) aged at temperatures of 700, 800 and 900 deg. C for times from 10 to 1000 min. The aging process at 700 and 800 deg. C caused the decrease in the Charpy V-Notch impact energy at - 196 deg. C because of the intergranular precipitation of carbides. Scanning electron micrographs of the Charpy V-Notch test specimens showed the presence of intergranular brittle fracture. The degree of sensitization was determined by the ratio of the maximum current density generated by the reactivation scan to that of the anodic scan, I{sub r}/I{sub a}, using the double-loop electrochemical potentiokinetic reactivation test. The Charpy V-Notch impact energy decreased with increase in the I{sub r}/I{sub a} ratio. This relation permits an estimate of the deterioration of cryogenic toughness due to thermal aging in this type of steel.

• OSTI ID: 21192596
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 2 Vol. 60; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AGING
AUSTENITIC STEELS
CARBIDES
CURRENT DENSITY
ELECTROCHEMISTRY
FRACTURES
PRECIPITATION
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K