Studies on Corrosion Behavior of Q235 Steel by Iron Bacteria in Sedimentary Water from Storage Tank

2010 ◽  
Vol 97-101 ◽  
pp. 538-542 ◽  
Author(s):  
Yong Zhang Zhou ◽  
Xin Ni ◽  
Dong Liang Han ◽  
Dong Sheng Chen ◽  
Ye Chen ◽  
...  

In this paper, the corrosion behavior of Q235 steel by iron bacteria in the sedimentary water was studied by using static hanging piece method, and the corrosion characteristic was also studied by using potentiodynamic polarization curve technique and hysteresis loop methods. The results showed that, the corrosion current density of Q235 steel in iron bacteria was higher than in the sterile medium, and the corrosion potential moved negatively; Iron bacteria reduced the corrosion resistance of steel Q235; Anodic polarization curves of Q235 steel in iron bacteria didn’t showed passivation characteristic, and the cathodic polarization curves had obvious hydrogen depolarization characteristic; The presence of iron bacteria could accelerate the the pitting corrosion of Q235 steel.

2011 ◽  
Vol 337 ◽  
pp. 281-284
Author(s):  
Dong Sheng Chen ◽  
Yong Zhang Zhou ◽  
Min Liu ◽  
Kai Wei Guo ◽  
Wu Ji Wei

The corrosion behavior of Q235 steel by Iron Bacteria (IB), Sulfate-reducing Bacteria (SRB) and Total General Bacteria (TGB) in sedimentary water of storage tank from an aromatics plant was investigated mainly by static hanging piece method, potentiodynamic polarization curve and hysteresis loop method. The results showed that the interaction of IB, SRB and TGB accelerated the corrosion rate of Q235 steel. The corrosion current density of Q235 steel electrode in IB, SRB and TGB solution was higher than that in the sterile solution, and the corrosion potential shifted in negative direction. IB, SRB and TGB reduced the corrosion resistance of Q235 steel. The corrosion of Q235 steel in the mixture of IB, SRB and TGB was more serious than in a single microbial system. The presence of IB, SRB and TGB made the pitting occur easily.


2010 ◽  
Vol 663-665 ◽  
pp. 473-476
Author(s):  
Shu Qi Zheng ◽  
Chang Feng Chen ◽  
Rui Jing Jiang ◽  
Dan Ni Wang

In the environment with H2S/CO2 or Na2S, the corrosion behavior of Lanthanum hexaboride (LaB6) was investigated by electrochemistry methods. The results indicated that the corrosion potential (Ecorr) and Rf of LaB6 increased as the partial pressure of H2S increased, while the corrosion current density (Icorr) decreased. In the environment containing Na2S, as the content of Na2S increased, the corrosion potential (Ecorr) and Rf of LaB6 decreased, while the corrosion current density (Icorr) increased. Thus, the addition of H2S into the environment with H2S/CO2 would inhibit the corrosion of LaB6; while in the environment containing Na2S, the increasing of the content of Na2S would accelerate the corrosion of LaB6.


2013 ◽  
Vol 368-370 ◽  
pp. 919-924
Author(s):  
Zhong Lu Cao ◽  
Makoto Hibino ◽  
Hiroki Goda

The influence of nitrite concentration on the linear polarization curves of steel, Tafel slope and Stern-Geary constant B have been investigated in three different pH environments simulating the highly alkaline environment, carbonated environment and neutral environment that really existed on the surface of steel in concrete. The results indicate that when the steel is in passive state, the presence of nitrite has little influence on anodic/cathodic polarization curves and Stern-Geary constant B; but when the steel is corroded, the presence of nitrite not only reduces the current density of anodic polarization curve but also decreases the value of Stern-Geary constant B. If this influence is not considered in practical corrosion measurement, the corrosion current will be overestimated.


2012 ◽  
Vol 487 ◽  
pp. 53-57
Author(s):  
Mei Cao ◽  
Zhong Cheng Guo ◽  
Xiang Lan Xie ◽  
Su Qiong He

Pb-PANI-WC inert anodes were prepared by direct current and pulse electrodeposition of PANI (conductive polyaniline) and WC particles with Pb2+ on the surface of titanium (Ti) substrate. The anodic polarization curves, cyclic voltammetry curves and Tafel polarization curves were measured in the solution of 50 g/L Zn2+, 150 g/L H2SO4 and 35°C, and the kinetic parameters of oxygen evolution, voltammetry charge, corrosion potential and corrosion current density have been obtained. The surface morphologies of the coating were investigated by using scanning electron microscope(SEM).The results show that the inert anodes prepared by pulse electrodeposition possess lower overpotential of oxygen evolution, higher electrocatalytic activity, and better reversibility of electrode reaction and corrosion resistance.


2011 ◽  
Vol 236-238 ◽  
pp. 1954-1957 ◽  
Author(s):  
Hong Chen ◽  
Jian Min Hao ◽  
Dong Xiao Li ◽  
Lian Ping Li

In this paper, the magnesium alloy AZ91D as biological implant material was treated by micro-arc oxidation. The effects on the coating growth of oxidation time and terminal voltages in zirconium solution and silicate solution were investigated respectively. Immersion and electrochemical tests were applied to study the corrosion behavior of AZ91D alloy in Hank’s solution. The results revealed that the coating thickness increases and the corrosion rate in immersion test decreases as the extension of oxidation time and the rising of terminal voltage. The corrosion rate of the alloy in the immersion test treated in zirconium solution varies with the terminal voltages and that in silicate solution depends on the coating thickness. In the polarization curves test, the corrosion current of the MAO treated alloy is two orders of magnitude lower than that of original samples and the polarization curves in zirconium solution show bigger anode and cathode polarizability which indicates that the MAO coating has a strong blocking effect of the corrosion. The corrosion resistance of MAO treated magnesium AZ91D improves significantly.


2021 ◽  
Vol 11 (18) ◽  
pp. 8668
Author(s):  
Jinbo Li ◽  
Ziying Zhu ◽  
Hongwei Chen ◽  
Shaojie Li ◽  
Hongyan Wu ◽  
...  

Corrosion behavior of 60Si2Mn-A and 60Si2Mn-B in simulated industrial atmospheric environment was investigated by alternate immersion corrosion test and electrochemical method. The phase, morphology, characteristics of corrosion products, and the distribution of Cr, Cu, and Ni in the corrosion products of experimental steel were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA). The results show that the phase of rust layer is Fe3O4 and γ-FeOOH in the early stage and then changes to α-FeOOH and γ-FeOOH in the later stage; the size of the rust layer with corrosion resistance of 60Si2Mn is less than 60Si2Mn; the Cr element accumulates in the rust layer of the experimental steel in the early stage of corrosion resistance; and Cu, Ni, and Cr in the corrosion resistance 60Si2Mn are concentrated in the rust layer near the substrate In the later stage of corrosion. As the corrosion cycle is prolonged, the corrosion potential and the resistance of the rust layer of the experimental steel increases, and the corrosion current decreases; in the same corrosion cycle, the corrosion potential and corrosion resistance of 60Si2Mn-B are greater than 60Si2Mn, and the corrosion current is less than 60Si2Mn.


2019 ◽  
Vol 66 (6) ◽  
pp. 704-718
Author(s):  
Qingmiao Ding ◽  
Zili Li ◽  
Tao Shen ◽  
Gan Cui

Purpose This paper aims to research the corrosion behavior of the metal under the disbonded coatings interfered with AC through electrochemical method. Design/methodology/approach The corrosion behavior of the metal under disbond coating interfered with alternate stray current (AC) was studied by electrochemical methods using the rectangular coating disbonded simulator. The obtained data from electrode potential test, electrochemical impedance spectroscopy (EIS) and polarization curves in simulated soil solution indicated that under the natural corrosion condition, the self-corrosion potential and the corrosion current density of the metal at different depths under disbond coating had obviously changed if there was AC interference. Findings The self-corrosion potential of the metal at the same depths under disbond coating shifted negatively with the rising of the AC voltage. Under the condition of cathode polarization, there was still obvious potential gradient with the extension of the deep peeling of the coating gap, and the corrosion current density of the test points was minimum, and the protection effect was best when the cathode protection potential was −1.0 V. When the metal was applied with over-protection, the corrosion rate of the metal increased as AC stray current flowing through it increased. Originality/value This paper used the rectangular aperture device to study the corrosion behavior of X80 steel under the disbonded coatings through electrochemical methods when the AC stray current interference voltage was 0V, 1V, 5V or 10V and the protection potential was 0V, −0.9V, −1.0V, −1.2V or −1.3V, respectively. There is great significance to the safe operation and long-term service of pipeline steel in soil environment.


2008 ◽  
Vol 135 ◽  
pp. 127-130
Author(s):  
Gyoung Ja Lee ◽  
Sang Hoon Lee ◽  
Sung Mo Hong ◽  
Byung Sun Han ◽  
Jin Ju Park ◽  
...  

In the present work, corrosion characteristics of ceramic dispersion strengthened (CDS) high-Cr stainless steel (SS) has been investigated. For the preparation of CDS SS with uniformly distributed reinforcements, TiC particles were mechanically activated with Cu powder by using high-energy ball mill machine, and then Cu-coated TiC particles were mixed with molten SS. Potentiodynamic polarization curves were experimentally measured on unmodified SS and CDS SS in 0.05 M NaCl solution. The values of corrosion potential Ecorr, corrosion current io, pitting potential Epit and polarization resistance Rp were quantitatively determined from the measured potentiodynamic polarization curves. From the result, it is concluded that CDS SS exhibits higher corrosion resistivity than unmodified SS.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Qingmiao Ding ◽  
Liping Fang ◽  
Yanyu Cui ◽  
Yujun Wang

A rectangle disbonded coating simulation device was used to research the effect of sulfate reducing bacteria (SRB) on the metallic corrosion behavior under disbonded coating by the electrochemical method. The results showed that the metal self-corrosion potential at the same test point had little change in the initial experiment stage, whether the solution was without or with SRB. The potential amplitude in the solution with SRB was larger than that without SRB in the later corrosion period. The corrosion current density of the metal at the same test point increased gradually over time in the solution with or without SRB, and SRB could accelerate the corrosion of the metal in the disbonded crevice. The metal self-corrosion potential in the crevice had little change in the SRB solution environment after adding the fungicide, but the corrosion current density decreased significantly. That meant the growth and reproduction of SRB were inhibited after adding the fungicide, so the metal corrosion rate slowed down. Among the three kinds of solution environment, increasing the coating disbonded thickness could accelerate the corrosion of the metal in the crevice, and it was the largest in the solution with SRB.


2015 ◽  
Vol 816 ◽  
pp. 699-704
Author(s):  
Bo Lv ◽  
Da Tong Zhang

In this paper, W80CuNi0.3 alloy was prepared by cold isostatic pressing (CIP) and infiltration sintering, and its corrosion behavior was investigated by neutral salt spray accelerated test, immersion test and electrochemical measurement. It turned out that in the neutral salt spray and immersion test,the mass loss and corrosion rate of W80CuNi0.3 were far lower than those of 45 steel. The corrosion mainly occurs in the bonding phase of Cu, and the initial corrosion form of W80CuNi0.3 was pitting, the main reason of W80CuNi0.3 corrosion was Cl- erosion. The polarization curves analysis showed that compared with 45 steel, W80CuNi0.3 alloy had higher corrosion potential and lower corrosion current. Therefore, W80CuNi0.3 alloy are prone to stable passivation, so it has superior corrosion resistance.


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