Effect of dissolved oxygen on electrochemical corrosion behavior of 2205 duplex stainless steel in hot concentrated seawater

2021 ◽  
Vol 66 ◽  
pp. 177-185
Author(s):  
Hongtao Zeng ◽  
Yong Yang ◽  
Minhang Zeng ◽  
Moucheng Li
Keyword(s):  
Stainless Steel ◽  
Dissolved Oxygen ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
2205 Duplex Stainless Steel ◽  
Electrochemical Corrosion Behavior

scholarly journals Electrochemical Corrosion Behavior of Laser Welded 2205 Duplex Stainless-Steel in Artificial Seawater Environment under Different Acidity and Alkalinity Conditions

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1025 ◽  
Author(s):  
Hany S. Abdo ◽  
Asiful H. Seikh ◽  
Ubair Abdus Samad ◽  
Ahmed Fouly ◽  
Jabair Ali Mohammed
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Ph Value ◽  
Electrochemical Corrosion ◽  
Artificial Seawater ◽  
Stainless Steel Sample ◽  
2205 Duplex Stainless Steel ◽  
Electrochemical Corrosion Behavior ◽  
Seawater Environment

The electrochemical corrosion behavior of laser welded 2205 duplex stainless-steel in artificial seawater environment (3.5% NaCl solutions) with different acidity and alkalinity conditions (different pH values) was investigated using different techniques. Namely, capacitance measurements (Mott–Schottky approach), electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The formation of pitting corrosion on the exposure surfaces of the tested duplex stainless-steel samples was investigated and confirmed by characterizing the surface morphology using field emission scanning electron microscope (FE-SEM). Based on the obtained results, a proportional relation has been found between pH value of the solution medium and the generated film resistance due to the processes of charge transfer, which directly affecting the pitting formation and its specifications. Since the film layer composition created on the duplex stainless-steel surface is changes depending on the pH value, it was found that different bilayer structure type was generated according to the acidity or alkalinity level. The presented bilayer is almost composed from metal oxides, such as iron oxide and chromium oxide, as confirmed by Raman Spectroscopy technique. As the pits size and its quantity increased with decreasing pH value, it can be concluded that the corrosion resistance property of the laser welded 2205 duplex stainless-steel sample is improved on the alkalinity direction of the solution. Vice versa, higher acidic solution has more ability for corrosion.

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.

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