Effects of solution heat-treatment and nitrogen in shielding gas on the resistance to pitting corrosion of hyper duplex stainless steel welds

• Published in: Corrosion science Vol. 53; no. 5; pp. 1939 - 1947
• Main Authors: Kim, Soon-Tae, Jang, Seok-Hwan, Lee, In-Sung, Park, Yong-Soo
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2011; Elsevier
• Subjects: A. Stainless steel; Applied sciences; B. Polarization; B. SEM; C. Pitting corrosion; C. Welding; Corrosion; Corrosion environments; Corrosion resistance; Diffusion; Diffusion welding; Duplex stainless steels; Exact sciences and technology; Heat treatment; Joining, thermal cutting: metallurgical aspects; Metals. Metallurgy; Pitting (corrosion); Shielding; Welded joints; Welding; B. SEM; C. Pitting corrosion; C. Welding; A. Stainless steel; B. Polarization; Scanning electron microscopy; Heat treatment; Welding; Austenitic ferritic steel; Shielding; Nitrogen; Solution heat treatment; Pitting corrosion; Shielding gas; Welded joint; Stainless steel; Duplex stainless steel; Dual phase steel
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2011.02.013

► The pitting resistance of HDSS increased with the solution heat-treatment and the incorporation of nitrogen in the shielding gas. ► The PREN difference between α-phase and γ-phase was proportional to α-content. ► The effect of Cr 2N on the pitting corrosion was elucidated. The effects of solution heat-treatment and shielding gas on the pitting corrosion of hyper duplex stainless steel (HDSS) welds were investigated in highly concentrated chloride environments. The pitting resistance of a solution heat-treated HDSS after welding with an Ar shielding gas supplemented with N 2 was greatly increased due to the dissolution of Cr 2N in α-phase, which followed the diffusion of N atoms from the α-phase to the γ-phase and an increase of the γ-phase in the weld metal and heat affected zone. It was also attributed to a decrease of the pitting resistance equivalent number difference between the two phases.