Study on Corrosion Behavior of Hot Dip Coatings in Wet-Dry Cyclic Conditions

2013 ◽  
Vol 303-306 ◽  
pp. 2545-2551
Author(s):  
Bin Xie ◽  
Shao Hua Xing ◽  
Ji Da Chen ◽  
Yong Gui Yan ◽  
Yan Li

The corrosion of fasteners in ballast tank is much serious, due to the wet-dry corrosive conditions. Now most fasteners are protected by zinc-aluminium coating. In order to evaluate the anticorrosion performance of hot dip Galvanized (GI), Galfan (GF) and Galvalume (GL) coated fasteners in wet-dry cyclic conditions, the corrosion behavior of these coatings in 1h wet and 7h drying condition were investigated by electrochemical impedance spectroscopy technology. The corrosion rate of GI coating in drying condition is much faster than that in wet condition before 23rd cycle, after that time the corrosion rate in sea water is faster than that in drying condition, however the corrosion rate of GF coatings in drying condition is much slower than that in wet condition, and for GL coating, the polarization resistance is both than 104Ω•cm2, whether it is immersed in seawater or in drying condition, which suggests it has better anticorrosion performance. The corrosion rate of the GI, GF and GL coating is 30µm per year, 1.5µm per year and 1.3µm per year respectively and corrosion resistance of GL and GF is therefore twenty two and twenty times as that of GI.

2021 ◽  
Vol 904 ◽  
pp. 519-524
Author(s):  
Gui Yun Zhang ◽  
Yong Wang ◽  
Tian Wei Zhang ◽  
Chen Yu Zhao

Sea water resources are extensive and can be used to extinguish fires, but their corrosiveness is a major problem. Using the method of electrochemical workstation, the electrochemical corrosion behavior of aluminum sheet in artificial sea water solution and silica-coated artificial seawater was studied; by analyzing the surface morphology, polarization curve and electrochemical impedance spectroscopy, the electrochemical corrosion behavior of aluminum sheets under different immersion times and different immersion media is obtained. The conclusion is that the coating of nanosilica powder has a certain corrosion protection effect on artificial seawater.


2015 ◽  
Vol 1120-1121 ◽  
pp. 773-778
Author(s):  
Zhen Guang Liu ◽  
Xiu Hua Gao ◽  
Lin Xiu Du ◽  
Jian Ping Li ◽  
Ping Ju Hao

The corrosion behavior of pipeline steel containing 1%Cr is studied by using immersion experiment. The corrosion rust is characteried with macroscopic/microscopic surface morphology, corrosion kinetics and corrosion phases. The results demonstrate that the main corrosion products are lepidocrocite and goethite, Cr-rich compound consists of the inner layer. The corrosion process could be divided into three stages. At stage 1, the corrosion rate decreases fast, and the distributed corrosion products are formed. At stage 2, the granular corrosion products appear on coupons surface gradually, and a plain corrosion rate is obtained. At stage 3, a compact and dense corrosion layer attaches to coupons surface, and corrosion rate decreases mildly.


2013 ◽  
Vol 734-737 ◽  
pp. 1367-1373
Author(s):  
Guan Fa Lin ◽  
Xun Chang Dong ◽  
Shi Dong Zhu ◽  
Zhen Quan Bai

As an attempt to contribute to the understanding of the corrosion processes of anti-sulfur steel in CO2and H2S containing environment with different species, the corrosion behavior of SM 80SS tubing steel immersed in CO2and H2S containing solution was analyzed in this work. To determine the corrosion behavior of SM80SS steel, the linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) techniques were used, as well as weight loss test and surface analysis. The results showed that the presence of Cl-quickened the anodic dissolution processes and rapidly increased the corrosion rate of SM 80SS steel, and that the addition of Ca2+and Mg2+reduced corrosion rate. The corrosion processes of SM 80SS steel were controlled by the electrochemical reaction in the initial period and then converted to be controlled by electrochemical and activation reaction with increasing Cl-. Keywords: SM 80SS tubing steel; CO2/H2S corrosion; EIS; Chloride; Ca2++ Mg2+


CORROSION ◽  
2012 ◽  
Vol 68 (5) ◽  
pp. 421-431
Author(s):  
J.L. Gama-Ferrer ◽  
J.G. Gonzalez-Rodriguez ◽  
I. Rosales ◽  
J. Uruchurtu

A study of the effect of Sn (1, 2, 3.5, 4.5, and 5 wt%) and Bi (0.5, 1.5, 3, and 4%) on the corrosion behavior of Al in ethylene glycol (C2H6O2)-40% water mixtures at 20, 40, and 60°C has been carried out using electrochemical techniques. Techniques include potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN) measurements. The three techniques have shown that additions of either Sn or Bi contents increased the corrosion rate of pure Al in all cases, and that generally speaking, the corrosion rate increased by increasing the temperature except for the alloy containing 1% Sn + 4% Bi, which showed the lowest corrosion rate at 60°C. This was because of a galvanic effect from the presence of Sn and/or Bi particles on the surface alloy, which acted as local cathodes, leading to an acceleration of corrosion. Nyquist diagrams showed two semicircles at 20°C and only one at 40°C or 60°C for all the alloys, showing two different corrosion-controlling mechanisms. EN measurements showed evidence of a mixture of both localized and uniform types of corrosion for all Al-based alloys.


2013 ◽  
Vol 779-780 ◽  
pp. 74-77
Author(s):  
Dang Kun ◽  
Yong Xin Song ◽  
Xu Li Zhang

The metal corrosion of ballast tank caused by ships ballast water that has been electrolysed has been studied in the laboratory by means of statically immersing metal sample in treated sea water. Experimental tests show that the corrosion rate in the electrolyzed seawater is larger than that in the natural seawater, but the increment of the corrosion rate is not more than 35% in the first 12 hours in the medium with a 5 mg/L initial chlorine concentration and the corrosion rate will decrease with time.


CORROSION ◽  
10.5006/3428 ◽  
2020 ◽  
Vol 76 (11) ◽  
pp. 1050-1063
Author(s):  
Hong Ju ◽  
Weihui Xu ◽  
Jiejing Chen ◽  
Dalei Zhang ◽  
Guomin Liu ◽  
...  

The under-deposit corrosion behavior and mechanism of aluminum brass (HAl77-2) were investigated in artificial seawater with a custom double electrolytic cell. The experiments included linear polarization, electrochemical impedance spectroscopy, and multielectrode arrays analysis. The electrochemical results revealed a pronounced effect of temperature on the under-deposit corrosion behavior of HAl77-2. The corrosion of HAl77-2 inside the CaCO3 scale is aggravated with increasing temperature. However, the increasing frequency of the corrosion rate of HAl77-2 gradually decreased after 333 K. Moreover, in the desalination of artificial seawater, the corrosion rate of HAl77-2 in the occulated area initially increased and subsequently decreased with increasing Cl− concentration. The scanning electron microscopy and energy dispersive spectrometry analysis showed a remarkable appearance of selective localized corrosion on the surface of HAl77-2.


Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 949 ◽  
Author(s):  
Wei Wu ◽  
Hailong Yin ◽  
Hao Zhang ◽  
Jia Kang ◽  
Yun Li ◽  
...  

An investigation into the electrochemical corrosion behavior of X80 pipeline steel under different elastic and plastic tensile stress in a CO2-saturated NaCl solution has been carried out by using open-circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy, and surface analysis techniques. The results show that the corrosion rate of X80 steel first increases and then slightly decreases with the increase of elastic tensile stress, whereas the corrosion rate sharply increases with the increase of plastic tensile stress. Both elastic and plastic tensile stress can enhance steel corrosion by improving the electrochemical activity of both anodic and cathodic reactions. Moreover, compared with elastic tensile stress, plastic tensile stress has a more significant effect. Furthermore, electrochemical reactions for CO2 corrosion and mechanoelectrochemical effect are used to reasonably explain the corrosion behavior of stressed X80 steel in CO2 environment.


2010 ◽  
Vol 163-167 ◽  
pp. 3049-3054 ◽  
Author(s):  
Jin Jie Shi ◽  
Wei Sun

The effect of sulfate ions on the corrosion behavior of steel in ordinary Portland concrete (OPC) and high performance concrete (HPC) were investigated. Steel corrosion was evaluated by means of corrosion potential (Ecorr), linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and cyclic polarization (CP). The electrochemical results indicated that, compared to the pure chloride solution, the presence of sulfate ions in the chloride solution both reduced the time to corrosion initiation and lead to an increase in corrosion rate of steel in OPC specimens; however, the sulfate ions had negligible effect in HPC specimens. Furthermore, the corrosion rate of steel exposed to chloride solution was higher that to the sulfate solution both in OPC and HPC specimens.


2012 ◽  
Vol 229-231 ◽  
pp. 40-43
Author(s):  
Yong Liu ◽  
Xing Hua Tong ◽  
Bao Guo Li ◽  
Yan Gang Wang ◽  
Lin Sen Zhu

In order to study the corrosion behavior of Q235B steel in seawater at Weihai, the indoor simulated and accelerated corrosion test is carried out by adding H2O2 in seawater. Tafel polarization curves and electrochemical impedance spectroscopy (EIS) techniques are employed to investigate the corrosion electrochemical behavior of Q235B steel. Polarization curves and EIS are acquired by electrochemical workstation. From polarization curves, it is found that the corrosion rate rises rapidly during the initial period, and it becomes highest on the 3rd day, then drops, and tends to be stable after about 15 days. After that, the corrosion rate reduces slowly due to the covering effect of corrosion products, and then the conclusion is confirmed by EIS analysis. Analytical results indicate that the rust layer plays a positive role of hindering the corrosion process.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 880
Author(s):  
Ying Hu ◽  
Long Xin ◽  
Tingguang Liu ◽  
Yonghao Lu

The corrosion behavior of oilfield used L245N standard steel was tested in simulated oilfield solution by dynamic high-temperature autoclave. The corrosion products were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Electrochemical impedance spectroscopy (EIS) respectively. In addition, the corrosion rates and surface morphological characteristics of the steels after different exposure times were studied. The results showed that the corrosion rate decreased sharply and then increased with time in the high salinity flow solution, which was related to the formation of corrosion scale and the remaining cementite within it. At the beginning of the exposure time, the formed corrosion scale became thicker, resulting in a significant decrease of the corrosion rate. While with increasing time, on the one hand, the increased remaining cementite within corrosion scale facilitated the corrosion by the galvanic corrosion between the remaining cementite and the ferrite within the metal. On the other hand, the protective effect of corrosion scale formed on the remaining cementite skeleton declined due to the formation of large amounts of FexCa1−xCO3, which also promoted the corrosion rate of the steels, both these ways contributed to a slow increase of corrosion rate.


Sign in / Sign up

Export Citation Format

Share Document