Abstract
The simulated intercritical HAZ (ICHAZ), fine grained HAZ (FGHAZ) and coarse grained HAZ (CGHAZ) of weld joints for two Nb containing steels were prepared by means of heat treatment. Then their microstructure and distribution of nano-sized precipitates were characterized by means of optical microscopy and transmission electron microscopy. Their corrosion behavior in simulated seawater environments corresponding to shallow sea and deep sea of 600 m below sea level respectively were studied by conventional electrochemical techiques and immersion tests. It’s shown that the corrosion rate of ICHAZ and CGHAZ is much higher than that of FGHAZ. What’s more, with the addition of Nb, the microstructural homogeneity of the steel is improved and the corrosion products films formed on the steels become much compact, thus enhancing their corrosion resistance. Besides, the nano-sized NbC precipitates can act as traps for capturing hydrogen, thus enhancing their corrosion resistance also in the seawater of deep sea.
Original language | English |
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Pages (from-to) | 604-610 |
Number of pages | 7 |
Journal | Journal of the Chinese Society of Corrosion and Protection |
Volume | 36 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2016 Dec |
Externally published | Yes |
Keywords
- Corrosion behavior
- Deep seawater
- HAZ
- Nb
- Shallow seawater
ASJC Scopus subject areas
- Materials Science(all)
- Engineering(all)