| Title |
The Localized Corrosion Behavior Associated with Microstructure of F53 Super Duplex Stainless Steel |
| Authors |
김순태(Soon Tae Kim); 이인성(In Sung Lee); 공경호(Kyeong Ho Kong); 박용수(Yong Soo Park); 이종훈(Jong Hoon Lee); 양원존(Won Jon Yang) |
| DOI |
https://doi.org/10.3365/KJMM.2015.53.7.464 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
alloys; annealing; corrosion resistance; scanning electron microscopy; microstructure |
| Abstract |
The localized corrosion behavior associated with microstructure of F53 super duplex stainless steel (SDSS) was investigated using a potentiodynamic polarization test, a critical crevice temperature test, an electron probe micro-analyzer analysis, and scanning electron microscopy-energy dispersive spectroscopy analyses. Crevice corrosion was initiated at the α/γ phase boundaries, MOx inclusions (where M is Cr, Mn, Al, Fe, or Ti), as well as Cr and Mo depleted areas adjacent to the σ-phases precipitated in the F53 SDSS alloy. This alloy had been annealed at 1050 ℃ followed by improper water-cooling, and the corrosion was propagated into the α-phases because the pitting resistance equivalent number (PREN) of the α-phase was smaller than that of the γ-phase. As cooling rate increased, the variation of the α-phases decreased, and the content of the Cr and Mo rich σ-phases decreased, thereby increasing the corrosion resistance. |