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Vol.53, No.7, 464 ~ 474, 2015
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| Title |
| The Localized Corrosion Behavior Associated with Microstructure of F53 Super Duplex Stainless Steel |
| 김순태 Soon Tae Kim , 이인성 In Sung Lee , 공경호 Kyeong Ho Kong , 박용수 Yong Soo Park , 이종훈 Jong Hoon Lee , 양원존 Won Jon Yang |
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| 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. |
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| Key Words |
| alloys, annealing, corrosion resistance, scanning electron microscopy, microstructure |
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