Abstract
Recent studies have shown that crevice corrosion can
trigger stress corrosion cracking (SCC) of stainless
steels in dilute chloride or chloride-sulfate solutions,
even at ambient temperatures, usually considered to be
harmless. Various types of test specimens and crevice
geometries have also been used to study the SSC/SCC
behavior of nickel base alloys in H 2S-CO2 service.
Because of the increasing use of duplex stainless steels
in the offshore oil production, a question has invoked
whether the crevice corrosion impairs the sulfide stress
cracking (SSC) resistance of the super duplex stainless
steels. For answering this question the SSC resistance of
wrought seamless super duplex stainless steel tube UNS
S39274 was evaluated in 0.02 MPa partial pressure H2S -
0.5 MPa partial pressure CO2 with 120 g/l chlorides at 90
°C. The condition selected represent the NACE
MR0175/ISO15156 environmental and materials limits for
duplex stainless steels 40 < PREN = 45 used as down hole
tubular components. The SSC performance has been studied
with both U-bend and C-ring specimens and with different
crevice materials and geometries. The results show that
the crevice corrosion can initiate cracking in H2S-CO2
containing chloride solutions. So far, definite answer to
the question to which extent the crevice impairs the SSC
resistance has not yet been found out. One reason is that
the specimen type and crevice geometry plays significant
role in crack initiation. The metal-metal crevice with
U-bend specimens has proved to be the most aggressive to
initiate SSC. In the case of C-ring specimens the
residual stress state of the C-ring specimens has to be
taken account in loading and interpreting the results
Original language | English |
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Title of host publication | Proceedings |
Subtitle of host publication | Corrosion 2011, Conference & Expo |
Place of Publication | Houston, TX |
Publisher | National Association of Corrosion Engineers (NACE) |
Number of pages | 17 |
Volume | 1 |
ISBN (Print) | 978-1-6178-2593-4 |
Publication status | Published - 2011 |
MoE publication type | A4 Article in a conference publication |
Event | Corrosion 2011, Conference & Expo - Houston, TX, United States Duration: 13 Mar 2011 → 17 Mar 2011 |
Conference
Conference | Corrosion 2011, Conference & Expo |
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Country/Territory | United States |
City | Houston, TX |
Period | 13/03/11 → 17/03/11 |
Keywords
- Chlorides
- CO2
- crevice
- duplex stainless steel
- H2S
- sour environment
- stress corrosion
- sulphide stress cracking
- super duplex stainless steel