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Effect of Ferrite Proportion and Precipitates on Dual‐Phase Corrosion of S32750 Super Duplex Stainless Steel with Different Annealing Temperatures
Author(s) -
Shen Wei,
Wang Fuming,
Yang Zhanbing,
Sun Lijuan,
Li Yongliang,
Jin Jinan
Publication year - 2021
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.202000568
Subject(s) - materials science , annealing (glass) , metallurgy , dual phase steel , corrosion , austenite , ferrite (magnet) , microstructure , pitting corrosion , passivation , duplex (building) , beta ferrite , grain size , composite material , martensite , dna , layer (electronics) , biology , genetics
The effects of ferrite proportion and precipitates on the dual‐phase corrosion properties of S32750 super duplex stainless steel are investigated with different annealing temperatures. When the specimens are annealed at 900 and 950 °C, respectively, the dual‐phase microstructure changes due to the precipitation of σ phase. Meanwhile, the passivation behavior of the specimens weakens, and the pitting corrosion potential decreases. With the increase in annealing temperature, especially over 1150 °C, the ferrite content and the grain size increase significantly and the pitting resistance equivalent of the ferrite phase decreases. The optimal annealing temperature of the tested steel is 1050–1100 °C. Under this condition, the dual‐phase proportion is close to 1:1, no obvious secondary phase precipitates in the matrix, and both the ferrite and the austenite phases present excellent corrosion resistances.