scholarly journals Effect of Thiosulfate on Corrosion Behavior and Passive Films of Duplex Stainless Steel 2205 in Chloride Solutions

2019 ◽  
pp. 9960-9973 ◽  
Author(s):  
Jiantao Zhang ◽  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Passive Films ◽  
Chloride Solutions

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.

Corrosion Behavior of Duplex Stainless Steel in Industrial White Liquor

CORROSION ◽  
10.5006/2558 ◽  
2017 ◽  
Vol 74 (5) ◽  
pp. 543-550 ◽  
Author(s):  
Luiza Esteves ◽  
Mônica M.A.M. Schvartzman ◽  
Wagner Reis da Costa Campos ◽  
Vanessa F.C. Lins
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Corrosion Rate ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Extrapolation Method ◽  
White Liquor ◽  
Duplex Steel ◽  
Kraft Mill ◽  
Lower Corrosion Rate

Specimens of lean duplex and duplex stainless steel were exposed at 200°C in industrial white liquor from a Brazilian kraft mill using an autoclave to simulate the same conditions of digester processing. Tafel extrapolation method and weight loss were used to evaluate corrosion behavior of duplex steel in white liquor. The higher alloy steel, although presenting a lower corrosion rate than the lean duplex, presents a more severe selective attack on ferrite, at 200°C and 1.8 MPa, after Tafel extrapolation method in industrial white liquor.

scholarly journals Influence of Molybdenum on Microstructure and Pitting Corrosion Behavior of Solution-Treated Duplex Stainless Steel in a Lithium Chloride Solution

2019 ◽  
Vol 22 (suppl 1) ◽  
Author(s):  
Stephania Cappellari de Rezende ◽  
Isabela Dainezi ◽  
Raíra Chefer Apolinario ◽  
Lucíola Lucena de Sousa ◽  
Neide Aparecida Mariano
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Lithium Chloride ◽  
Pitting Corrosion ◽  
Chloride Solution ◽  
Solution Treated ◽  
Lithium Chloride Solution

Investigation of mechanical and corrosion behavior of laser hybrid weld joint of 2205 duplex stainless steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuanbo Zheng ◽  
Cheng Zhang ◽  
Xiao Yong Wang ◽  
Jie Gu
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Welded Joints ◽  
Two Phase ◽  
Content Type ◽  
2205 Duplex Stainless Steel ◽  
Laser Hybrid

Purpose Duplex stainless steel is composed of equal amounts of austenite and ferrite, which has excellent corrosion resistance and strength. However, after the metal was welded, the ratio of austenite and ferrite in the joint is unbalanced, and secondary phase precipitates are produced, which is also an important cause of pitting corrosion in the joint. Design/methodology/approach This paper aims to study the mechanical and corrosion behavior of welded joints, by adjusting the welding parameters of laser hybrid welding, dual heat sources are used to weld 2205 duplex stainless steel. The two-phase content of different parts of the welded joint is measured to study the influence of the ratio of the two-phase on the mechanical and corrosion properties of the joint. Findings The ratio of austenite and ferrite in different welded joints has an obvious difference, and from top to bottom, the austenite content decreased gradually, and the ferrite content increased gradually. The harmful phases are precipitated in the middle and lower part of the joint. The strength of welded joints is slightly lower than that of base metal. At the same time, the fracture analysis shows that some ferrite phases are affected by the precipitate in the grain and produce quasi-cleavage fracture. The corrosion results show that the corrosion resistance of the welded joints is lower than that of the base metal, and the concentration of chloride ions affects the corrosion resistance. Originality/value In this paper, the authors use the influence of different welding processes on the two-phase ratio of the joint to further study the influence of the microstructure on the corrosion resistance and mechanical properties of the weld.

scholarly journals Investigation on the Corrosion Behavior of Lean Duplex Stainless Steel 2404 after Aging within the 650–850 °C Temperature Range

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 529 ◽  
Author(s):  
Federica Zanotto ◽  
Vincenzo Grassi ◽  
Andrea Balbo ◽  
Fabrizio Zucchi ◽  
Cecilia Monticelli
Keyword(s):  
Stainless Steel ◽  
Grain Boundaries ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Thermal Aging ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Localized Corrosion ◽  
Fast Diffusion ◽  
Lean Duplex Stainless Steel

This paper reports the effects of thermal aging between 650 and 850 °C on the localized corrosion behavior of lean duplex stainless steel (LDSS 2404). Critical pitting temperature (CPT) and double loop electrochemical potentiokinetic reactivation (DL-EPR) tests were performed. The localization of pitting attack and intergranular corrosion (IGC) attack after DL-EPR was investigated by optical (OM) and scanning electron microscopy (SEM) and by focused ion beam (FIB) coupled to SEM. Thermal aging caused the precipitation of mainly chromium nitrides at grain boundaries. Aging at 650 °C or short aging times (5 min) at 750 °C caused nitride precipitation mainly at α/α grain boundaries as a result of fast diffusion of chromium in this phase. Aging at 850 °C or aging times from 10 to 60 min at 750 °C also allowed the precipitation at the α/γ interface. Nitrides at γ/γ grain boundaries were observed rarely and only after long aging times (60 min) at 850 °C. Electrochemical tests showed that in as-received samples, pitting attack only affected the α phase. Conversely, in aged samples, pitting and IGC attack were detected close to nitrides in correspondence of α/α and α/γ grain boundaries depending on aging temperatures and times.

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.

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