Influence of the shielding gas composition on the passive film and erosion corrosion of tube-to-tube sheet welds of hyper duplex stainless steel

2015 ◽  
Vol 91 ◽  
pp. 140-150 ◽  
Author(s):  
Hye-Jin Kim ◽  
Soon-Hyeok Jeon ◽  
Soon-Tae Kim ◽  
Yong-Soo Park
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Passive Film ◽  
Gas Composition ◽  
Tube Sheet ◽  
Shielding Gas ◽  
Erosion Corrosion

Corrosion behavior of a new 25Cr-3Ni-7Mn-0.66 N duplex stainless steel in artificial seawater

2021 ◽  
Vol 63 (6) ◽  
pp. 505-511
Author(s):  
Songkran Vongsilathai ◽  
Anchaleeporn Waritswat Lothongkum ◽  
Gobboon Lothongkum
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Passive Film ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Melting Furnace ◽  
Artificial Seawater ◽  
Vacuum Arc ◽  
Significant Difference ◽  
Type Semiconductor

Abstract A new duplex 25Cr-3Ni-7Mn-0.66 N alloy was prepared in a vacuum arc re-melting furnace and characterized by metallographic and EPMA methods. Its corrosion behavior was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and a Mott-Schottky (M-S) analysis in artificial seawater at room temperature and compared with those of super and normal commercial duplex stainless steel (SDSS and DSS). No significant difference in the open circuit potentials and pitting potentials was observed. Its passive film current density lies between those of SDSS and DSS. This was confirmed by EIS analysis. A pit attack was observed on the δ-phase for all duplex samples, because the PREN16 of the δ-phase was lower than that of the γ-phase. From the Mott-Schottky analysis, the passive films were found to be composed of bi-layer structures, a p-type semiconductor inner layer, and a n-type semiconductor outer layer. The degree of defect as well as the effect of nitrogen in passive film layer are discussed with respect to the point defect model.

Effect of hydrogen on semiconductor properties and pitting initiation of 2205 duplex stainless steel passivation film

2020 ◽  
Vol 67 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Chuanbo Zheng ◽  
Jiayan Huang ◽  
Gua Yi
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Passive Film ◽  
Corrosion Behavior ◽  
Current Density ◽  
Anodic Polarization ◽  
Content Type ◽  
2205 Duplex Stainless Steel ◽  
Passivation Film ◽  
Semiconductor Properties

Purpose This paper aims to study the effect of current density of hydrogen charging on the semiconductor properties and pitting initiation of 2205 duplex stainless steel (DSS) passivation film. Design/methodology/approach In this work, the 2205 DSS is pre-hydrogenated and passivated. Then, the passivation film is tested by electrochemical impedance method, Mott–Schottky curve method and dynamic potential scanning method. The influences of hydrogen on the properties of the passivation film and the corrosion behavior of the matrix were studied by analyzing the curves obtained in the electrochemical test. The surface of the passivation film after pre-hydrogenation and anodic polarization was observed by using the ultra-depth three-dimensional microscopy and the scanning electron microscope. The integrity, density and corrosion morphology of the passivation film were studied and discussed. Findings With the increase of the hydrogen current density, the growth of the passivation film is hindered, the concentrations of donor and acceptor in the film are increased, the conductivity of the passivation film increases. In the anodic polarization, the dimensional passive current density increases with the increase of the hydrogen current density, and the pitting potential is reversed, the more likely the sample is pitting. In general, hydrogen hinders the formation of the passive film on duplex stainless steel, which increases the concentration of point defects in the passive film. Finally, the passive film is easy to crack and pitting. Originality/value The performance of passive film is an important condition to influence the corrosion behavior of stainless steel. However, little research has been done on the effects of hydrogen on the electrochemistry and pitting sensitivity of 2205 DSS passivation films. The effect of hydrogen on semiconductor properties and pitting initiation of 2205 DSS passivation film is needed to be investigated.

Influence of Surface Strain on Passive Film Formation of Duplex Stainless Steel and Its Degradation in Corrosive Environment

2019 ◽  
Vol 166 (11) ◽  
pp. C3071-C3080 ◽  
Author(s):  
Cem Örnek ◽  
Marie Långberg ◽  
Jonas Evertsson ◽  
Gary Harlow ◽  
Weronica Linpé ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Passive Film ◽  
Film Formation ◽  
Surface Strain ◽  
Corrosive Environment
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