Effect of Annealing Temperature on the Mechanical and Corrosion Behavior of a Newly Developed Novel Lean Duplex Stainless Steel

Materials

Yanping Wu¹  Yanjun Guo²  Jin Li²  Jincheng Hu³  Laizhu Jiang³  Tianwei Liu⁴ 

[1] China Academy of Engineering Physics, P.O. Box 919-71, Mianyang 621900, Sichuan Province, China;Department of Materials Science, Fudan University, No. 220, Handan Road, Shanghai 200433, China;Research and Development Center, Baosteel Co., Ltd., No. 885, Fujin Road, Shanghai 201900, China;Science and Technology on Surface Physics and Chemistry Laboratory, P.O. Box 718-35, Mianyang 621907, Sichuan Province, China;

关键词: lean duplex stainless steel;    annealing temperature;    mechanical properties;    TRIP effect;    pitting corrosion behavior;    PREN;    Volta potential;   

DOI  :  10.3390/ma7096604

来源: DOAJ

【 摘 要 】

The effect of annealing temperature (1000–1150 °C) on the microstructure evolution, mechanical properties, and pitting corrosion behavior of a newly developed novel lean duplex stainless steel with 20.53Cr-3.45Mn-2.08Ni-0.17N-0.31Mo was studied by means of optical metallographic microscopy (OMM), scanning electron microscopy (SEM), magnetic force microscopy (MFM), scanning Kelvin probe force microscopy (SKPFM), energy dispersive X-ray spectroscopy (EDS), uniaxial tensile tests (UTT),and potentiostatic critical pitting temperature (CPT). The results showed that tensile and yield strength, as well as the pitting corrosion resistance, could be degraded with annealing temperature increasing from 1000 up to 1150 °C. Meanwhile, the elongation at break reached the maximum of 52.7% after annealing at 1050 °C due to the effect of martensite transformation induced plasticity (TRIP). The localized pitting attack preferentially occurred at ferrite phase, indicating that the ferrite phase had inferior pitting corrosion resistance as compared to the austenite phase. With increasing annealing temperature,the pitting resistance equivalent number (PREN) of ferrite phase dropped, while that of the austenite phase rose. Additionally, it was found that ferrite possessed a lower Volta potential than austenite phase. Moreover, the Volta potential difference between ferrite and austenite increased with the annealing temperature, which was well consistent with the differenceof PREN.

【 授权许可】

Unknown