Crevice corrosion of corrosion-resistant alloys in simulated sour gas environments

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3585279· OSTI ID:7048575

Azuma, S; Kudo, T ^[1]

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1. Sumitomo Metal Industries Ltd., Amagasaki, Hyogo (Japan). Central Research Labs.

This paper discusses crevice corrosion behaviors of corrosion-resistant alloys (CRAs) with various Ni, Cr, and Mo contents investigated in conditions simulating the sour gas environment encountered in oil and gas production. Crevice corrosion occurred more easily in a 0.1 MPa H{sub 2}S environment than in a 1.0 MPa H{sub 2}S environment. Ni, Cr and Mo all improved crevice corrosion resistance in electrochemical and immersion tests. The improving effect of Ni and Cr on crevice corrosion resistance reached saturation at 20 percent of their contents. Alloys containing more than 6% Mo exhibited excellent crevice corrosion resistance, which could not be achieved by the increment in Ni and Cr contents. The onset of the crevice corrosion on CRAs in H{sub 2}S-Cl{sup {minus}} environment was investigated by electrochemically studying the pH drop in the crevice solution and the depassivation pH (pH{sub d}). These are considered to determine the extent of crevice corrosion resistance in comparison to that in O{sub 2}-Cl{sup {minus}} environment. It has been shown that the crevice corrosion frequency from the immersion test in 0.1 MPa H{sub 2}S was better correlated with the pH{sub d} in the deaerated solution rather than the pH{sub d} in the H{sub 2}S containing solution. The crevice corrosion resistance under 0.1 and 1 MPa H{sub 2}S is discussed in relation to the pH{sub d} dependent on the H{sub 2}S concentration in the crevice.

• OSTI ID: 7048575
• Journal Information: Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 47:6; ISSN CORRA; ISSN 0010-9312
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
032000 -- Natural Gas-- Transport
Handling
& Storage
033000 -- Natural Gas-- Properties & Composition
36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400 -- Electrochemistry
ALLOYS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CORROSION
CORROSION RESISTANCE
CORROSION RESISTANT ALLOYS
CREVICE CORROSION
ELECTROCHEMICAL CORROSION
ENERGY SOURCES
ENVIRONMENTAL EFFECTS
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
MATERIALS TESTING
MOLYBDENUM ALLOYS
NATURAL GAS
NICKEL ALLOYS
PIPELINES
TESTING