Corrosion Rate of Alloy 22 as a Function of Immersion Time

Journal Article · Mon Mar 21 04:00:00 EST 2005 · TMS Letters

OSTI ID:877831

Estill, J C; Hust, G A; King, K J; Rebak, R B

Alloy 22 (N06022) is a nickel (Ni) based alloy containing nominally 22% Chromium (Cr), 13% Molybdenum (Mo) and 3% tungsten (W). Alloy 22 is highly resistant to general and localized corrosion such as pitting corrosion and stress corrosion cracking. Due to the formation of a stable passive film, when Alloy 22 is immersed in certain electrolytes, its corrosion potential (E{sub corr}) increases and its corrosion rate (CR) decreases as a function of the immersion time. This paper discusses the evolution of E{sub corr} and corrosion rate (CR) of creviced Alloy 22 specimens in six different mixtures of sodium chloride (NaCl) and potassium nitrate (KNO{sub 3}) at 100 C. Two types of specimens were used, polished as-welded (ASW) and as-welded solution plus heat-treated (ASW+SHT). The latter contained the black annealing oxide film on the surface. Results show that, for the two type of materials, as the immersion time increases, E{sub corr} increased and the CR decreased. Even for concentrated brine solutions at 100 C the CR was < 50 nm/year after more than 100 days immersion.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 877831
• Report Number(s): UCRL-JRNL-210726
• Journal Information: TMS Letters, Journal Name: TMS Letters Journal Issue: 1 Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
ANNEALING
BRINES
CHROMIUM
CORROSION
ELECTROLYTES
MIXTURES
MOLYBDENUM
NICKEL
OXIDES
PITTING CORROSION
POTASSIUM NITRATES
SODIUM CHLORIDES
STRESS CORROSION
TUNGSTEN