Mechanism of lead-induced stress corrosion cracking of nickel-based alloys in high-temperature water

Journal Article · Wed Jul 01 04:00:00 EDT 1998 · Corrosion

DOI:https://doi.org/10.5006/1.3284879· OSTI ID:634553

Sakai, T; Nakagomi, N; Kikuchi, T; Aoki, K; Nakayasu, F ^[1]; Yamakawa, K ^[2]

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1. Nuclear Fuel Industries, Ltd., Osaka (Japan)
2. Univ. of Osaka, Sakai, Osaka (Japan)

A study was undertaken to better understand the lead-induced corrosion mechanism of nickel-based alloys used for steam generator tubing materials (alloys 600 and 690 [UNS N06600 and N06690]) in pressurized-water reactor (PWR) plants. Electrochemical measurements (corrosion potential and polarization measurements) and constant extension rate tests (CERT) of tubing materials were performed in lead-contaminated environments. Results of electrochemical measurements showed lead did not raise the corrosion potential but did increase the anodic polarization current in the passivity region, which indicated degradation of the passive oxide film. CERT results showed alloy 690 had better corrosion resistance than alloy 600, which was in good agreement with the lower intensity of the anodic current. The mechanism of lead-induced corrosion was proposed as disruption of the oxide film of the alloys as a result of the incorporation of lead.

• Sponsoring Organization: USDOE
• OSTI ID: 634553
• Journal Information: Corrosion, Journal Name: Corrosion Journal Issue: 7 Vol. 54; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
CRACK PROPAGATION
ELECTROCHEMISTRY
EXPERIMENTAL DATA
FRACTURE PROPERTIES
LEAD
METALLURGICAL EFFECTS
NICKEL BASE ALLOYS
PWR TYPE REACTORS
STEAM GENERATORS
STRESS CORROSION
TUBES