Premium
Effect of annealing temperature on pitting behavior and microstructure evolution of hyper‐duplex stainless steel 2707
Author(s) -
Sun Li,
Sun Yangting,
Liu Yuanyuan,
Dai Nianwei,
Li Jin,
Jiang Yiming
Publication year - 2019
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.201910801
Subject(s) - austenite , materials science , microstructure , annealing (glass) , metallurgy , ferrite (magnet) , duplex (building) , pitting corrosion , composite material , corrosion , chemistry , dna , biochemistry
Hyper‐duplex stainless steel (HDSS) 2707 is a competitive material for application in extremely caustic environments. In this study, different annealing temperatures ranging from 1020°C to 1200°C were examined by electrochemical tests and microstructure analysis. The microstructure characterization indicated that precipitations were detected when the annealing temperature was below 1050°C and a relatively balanced austenite–ferrite phase structure was obtained at 1100°C. Through electrochemical measurements in NaBr solution, it was revealed that with the increase of temperature the pitting resistance of HDSS 2707 first rose then declined, peaking at 1100°C. The highest critical pitting temperature was about 67°C. In addition, the pitting position shifted from austenite phase to austenite–ferrite boundary and finally to ferrite interior with the annealing temperature increasing, which was in agreement with the pitting resistance equivalent values (PREN) of the two phases.