Corrosion Behavior Difference in Initial Period for Hot-Rolled and Cold-Rolled 2205 Duplex Stainless Steels

Metals

Peide Han¹  Qi Sun¹  Jian Wang¹  Tao Gao¹ 

[1] College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China;

关键词: pitting;    sigma phase;    2205;    duplex stainless steel;   

DOI  :  10.3390/met8060407

来源: DOAJ

【 摘 要 】

Precipitate phases often play an important role on the corrosion resistance of 2205 Duplex stainless steels (DSS). In the present paper, the microstructure and the corrosion resistance of the hot-rolled and cold-rolled 2205 steels aged for different times at 850 °C was investigated through XRD, SEM, and potentiodynamic polarization. It was discovered that the Chi(χ) phase and Sigm(σ) phase were precipitated in turn following the aging treatment of the hot-rolled and cold-rolled steels, but the precipitate amount in the cold-rolled samples was significantly higher when compared to the hot-rolled samples. The corrosion resistance of the solution-annealed cold-rolled samples was similar to the hot-rolled samples, but the corrosion resistance of the cold-rolled sample with precipitate was weaker when compared to the hot-rolled sample following aging treatment. Pitting preferentially initiates in the Cr-depleted region from the σ phase in the aged hot-rolled 2205, becoming increasingly severe during aging for a long lime. Adversely, the initiation of pitting corrosion might occur at the phase boundary, defects, and martensite in the aged cold-rolled 2205. The σ phase was further selectively dissolved through the electrochemical method to investigate the difference in microstructure and corrosion behavior of the hot-rolled and cold-rolled 2205 duplex stainless steels.

【 授权许可】

Unknown