Effect of Mo and Mn Additions on Tensile and Corrosion Behaviors of CD4MCU Cast Duplex Stainless Steels

摘要

Despite the significant use in the industry, the effect of Mo and Mn on the tensile and corrosion behavior of cast duplex stainless steels has not been well established. In the present study, the tensile and corrosion behaviors of CD4MCU cast duplex stainless steels with different Mo and Mn contents were examined. The polarization and the in-situ slow strain rate tests were conducted in 3.5% NaCl + 5% H{sub}2SO{sub}4 aqueous solution to quantify the resistances to pitting corrosion and stress corrosion cracking with different Mo and Mn contents. The addition of Mo and/or Mn, which stabilized ferrite in the present study, affected the microstructure of the present alloy, and eventually the tensile and corrosion behavior in a complex manner. The relationship between the microstructural evolution and the tensile and corrosion behavior of CD4MCU cast duplex stainless steels with different Mo and Mn contents was discussed based on the micrographic and fractographic observations.