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Corrosion resistance of SG tubing material Incoloy 800 mod. and Inconel 690 TT
Author(s) -
Kilian R.,
Wieling N.,
Stieding L.
Publication year - 1991
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.19910420907
Subject(s) - incoloy , corrosion , materials science , metallurgy , stress corrosion cracking , inconel , cracking , composite material , alloy
The corrosion resistance of the SG tubing material Incoloy 800 mod. and Inconel 690 TT is considered with respect to pitting, sensitization characteristics and stress corrosion cracking, especially chloride‐induced cracking, pure water cracking and caustic cracking. Based on laboratory data Incoloy 800 mod. as well as Inconel 690 TT show very good corrosion resistance under specified and faulted SG water conditions. The published results often refer to Incoloy 800 according to ASTM B 163–66. It is shown that the Incoloy 800 grade used by nuclear power suppliers is optimized for this application. The restricted chemical composition of the modified grade of Incoloy 800 vs. the standard grade is discussed and it is shown that this results in a significantly higher resistance to the above mentioned corrosion phenomena. The operating experience with Incoloy 800 mod. heat transfer tubes in nuclear steam generators is discussed briefly with respect to corrosion. No materrial‐specific weaknesses have been observed with Incoloy 800 mod. Since more than 19 years of operation only at one tube out of 235 000 SG tubes made of Incoloy 800 mod. a leakage caused by corrosion has been occurred. This finding is independent of different tube manufacturers and different water treatments of the various plants.