scholarly journals Dissolution of chromium in sulfuric acid

2002 ◽  
Vol 67 (11) ◽  
pp. 777-782 ◽  
Author(s):  
Dragutin Drazic ◽  
Jovan Popic
Keyword(s):  
Corrosion Rate ◽  
Room Temperature ◽  
Corrosion Potential ◽  
Analytical Data ◽  
Electrochemical Corrosion ◽  
Spectrophotometric Analysis ◽  
Weight Loss Method ◽  
Loss Method ◽  
Anomalous Dissolution

By combining electrochemical corrosion rate measurements and spectrophotometric analysis of the electrolyte it was shown that at room temperature chromium dissolves in deaerated 0.1M Na2SO4 + H2SO4 (pH1) solution as Cr(II) and Cr(III) ions in he ratio Cr(II):Cr(III)?7:1. This process was stable over 4h without any detectable change. The total corrosion rate of chromium calculated from the analytical data is about 12 times higher, than that determined electrochemically by cathodic Tafel line extrapolation to the corrosion potential. This finding was confirmed by applying the weight-loss method for the determination of the corrosion rate. This enormous difference between these experimentally determined corrosion rates can be explained by the rather fast, "anomalous" dissolution process proposed by Kolotyrkin and coworkers (chemical reaction of Cr with H2O molecules) occurring simultaneously with the electrochemical corrosion process.

Electrochemistry of Active Chromium: Part 1—Anomalous Corrosion and Products of Chromium Dissolution in Deaerated Sulfuric Acid

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 297-303 ◽  
Author(s):  
D. M. Dražić ◽  
J. P. Popić
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Rate ◽  
Electrochemical Corrosion ◽  
Metal Corrosion ◽  
Chemical Dissolution ◽  
Rate Measurement ◽  
Electrochemical Processes ◽  
Corrosion Rate Measurement ◽  
Anomalous Dissolution

Abstract Chromium corroding in deaerated aqueous solution of sulfuric acid (H2SO4; pH 1 to 3) produces Cr(II) and Cr(III) ions simultaneously in the ratio 7:1, as well as H2. The corrosion potentials of electrochemically activated chromium are determined by the electrochemical processes as expected according to the Wagner-Traud model. However, the real rates of chromium corrosion determined by collecting evolved hydrogen, spectrophotometric determination of the accumulated Cr ions in the solution, or by weight-loss measurements are higher than the electrochemical dissolution rate by up to 12 times for pH 1.0. The effect is smaller for higher pH. This was due to the simultaneous “anomalous” (or chemical) dissolution process of the direct chemical reaction of Cr with H2O molecules, as proposed some time ago by Kolotyrkin and coworkers. Since “anomalous” dissolution cannot be detected by electrochemical means, it has been pointed out that in the presence of “anomalous” dissolution processes during metal corrosion, electrochemical corrosion rate measurements should be taken only as approximate, while the level of approximation should be determined by some other direct corrosion rate measurement method.

The Influence of Different Gas Welding Flame on Corrosion Behavior of the Carbon Steel’s Heat Affected Zone in Seawater

2015 ◽  
Vol 1120-1121 ◽  
pp. 1059-1063
Author(s):  
Cai Xiang Gu ◽  
Guang Wei Liu ◽  
Yu Dong Xu
Keyword(s):  
Corrosion Rate ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Heat Affected Zone ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Electroanalytical Chemistry ◽  
Microstructure Observation ◽  
Weight Loss Method ◽  
Loss Method

The influence of different flame of gas welding on corrosion behavior of the carbon steel’s heat affected zone in seawater were studied by the weight-loss method, electroanalytical chemistry method and surface and microstructure observation. The result indicate that when gas welding the carbon steel, the corrosion rate of the heat affected zone under the influence of mild carbonizing flame is 0.1252[g／(m2•h)], in contrast, the corrosion rate of that under the influence of neutral flame is 0.1025[g／(m2•h)]; the order of corrosion current shows as follows: Imild carbonizing flame>Ineutral flame>Ibase metal; the order of measured corrosion potential as follows: Ebase metal>Eneutral flame>Emild carbonizing flame. Compared with the base metal, the heat effected zone are more likely to corrosion, corrosion resistance of the sample under mild carbon flame are the worse.

Experimental Research on Erosion of P110 Tubing during Perforating

2014 ◽  
Vol 1073-1076 ◽  
pp. 2244-2247
Author(s):  
Hu Sun ◽  
Zhi Jun Ning ◽  
Zu Wen Wang ◽  
Zhen Li ◽  
Zhi Guo Wang
Keyword(s):  
Weight Loss ◽  
Erosion Rate ◽  
Large Scale ◽  
Guar Gum ◽  
Electrochemical Corrosion ◽  
Low Velocity ◽  
Gas Field ◽  
Weight Loss Method ◽  
Loss Method ◽  
Gas Fields

Erosion is a main failure of tubings and downhole tools in Changqing gas field. It is necessary to evaluate the erosion rate for the safety of tubing and strings. In this paper, the erosion of P110 steel, in the 0.2%wt guar gum fracturing fluid which contains sands, is investigated by weight loss method in the self-made jet experiment device. It is indicated that the erosion rate increases with the increment of slurry velocity exponentially. When the slurry velocity is in low velocity area, the electrochemical corrosion of dissolved oxygen dominates in erosion mechanism; when slurry velocity increases into middle velocity area, the weight loss is controlled by the synergism of corrosion-erosion; and when the slurry velocity increases into high velocity area, the weight loss rate is dominantly depended on erosion of particles. The results can provide guidelines for large-scale fracturing work of Changqing gas fields.

scholarly journals Electrochemistry of active chromium, part III: Effects of temperature

2003 ◽  
Vol 68 (11) ◽  
pp. 871-882 ◽  
Author(s):  
Jovan Popic ◽  
Dragutin Drazic
Keyword(s):  
Corrosion Rate ◽  
Hydrogen Evolution ◽  
Anodic Dissolution ◽  
Electrochemical Corrosion ◽  
Potential Range ◽  
Temperature Dependences ◽  
Hydrogen Evolution Reactions ◽  
Effects Of Temperature ◽  
Best Fit ◽  
Anomalous Dissolution

It was shown that the temperature in the range 20 ? 65 ?C has considerable effects on the electrochemical anodic dissolution of chromium in the active potential range as well as on the electrochemical hydrogen evolution reactions on bare and oxide covered chromium surfaces. Also, the chemical dissolution of chromium is strongly affected. The apparent energy of activation for anodic dissolution is 63.1 kJ mol-1, for hydrogen evolution on a bare Cr surface 19.5 kJ mol-1, for the same reaction on an oxide covered surface 44.0 kJ mol-1 and for the chemical ("anomalous") dissolution 66.9 kJ mol-1. The temperature dependences of the total corrosion rate, and the electrochemical corrosion rate alone, are presented in polynomial forms with the appropriate constants obtained by the best fit of the experimental data. For the hydrogen evolution reaction on both bare and oxide covered chromium, the Volmer-Heyrovsky reaction mechanism with the second step as rate determining was proposed.

Corrosion Behaviour of Aluminium Alloy in Palm Oil Methyl Ester (B100)

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
W. B. Wan Nik ◽  
S. Syahrullail ◽  
R. Rosliza ◽  
M. M. Rahman ◽  
M. F. R. Zulkifli
Keyword(s):  
Weight Loss ◽  
Methyl Ester ◽  
Corrosion Rate ◽  
Aluminium Alloy ◽  
Palm Oil ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Electrochemical Test ◽  
Weight Loss Method ◽  
Loss Method

The aim of this study is to determine the corrosion effect of palm oil methyl ester (POME) on aluminium alloy 5083 (AA5083). The static immersion test was carried out at 60°C for 68 days according to ASTM G–31–72. The corrosion analysis was done by using weight loss method and electrochemical test. The result from weight loss method shows the decreasing in weight loss of AA5083 which signifies the ability of POME to reduce corrosion rate. The electrochemical test shows the decreasing in polarization resistance,Rp, while the corrosion current densities, Icorr, increase. The corrosion rate reduces from 2.250mpy to 0.1946mpy. The low concentration of fatty acid C18:2 and high anti oxidant element contributes to the reduction of corrosion rate of AA5083 in POME.

Inhibition of Aloe in Corrosion Experimental Research

2011 ◽  
Vol 233-235 ◽  
pp. 648-651
Author(s):  
Ai Jun Wei ◽  
Bei Feng ◽  
Xin Zhang ◽  
Fu Yong Huo
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Work Environment ◽  
Corrosion Inhibition ◽  
Corrosion Test ◽  
Inhibition Effect ◽  
Corrosion Medium ◽  
Different Temperatures ◽  
Weight Loss Method ◽  
Loss Method

In this corrosion test, simulated brine is used as corrosion medium, added different concentrations of aloe juice. Static weight-loss method is employed, meanwhile, we calculated corrosion rate of Q235 steel and researched on the corrosion inhibition effect of aloe in different temperatures. Results show that aloe is a good inhibitor, rate of corrosion inhibition can reach 80% or more and suitable for the temperature of work environment is less than 60 °C.

scholarly journals Microbial Corrosion of API 5L X-70 Carbon Steel by ATCC 7757 and Consortium of Sulfate-Reducing Bacteria

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Arman Abdullah ◽  
Nordin Yahaya ◽  
Norhazilan Md Noor ◽  
Rosilawati Mohd Rasol
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Sulfate Reducing Bacteria ◽  
Desulfovibrio Vulgaris ◽  
Corrosion Morphology ◽  
Sulfate Reducing ◽  
Weight Loss Method ◽  
Loss Method ◽  
Reducing Bacteria

Various cases of accidents involving microbiology influenced corrosion (MIC) were reported by the oil and gas industry. Sulfate reducing bacteria (SRB) have always been linked to MIC mechanisms as one of the major causes of localized corrosion problems. In this study, SRB colonies were isolated from the soil in suspected areas near the natural gas transmission pipeline in Malaysia. The effects of ATCC 7757 and consortium of isolated SRB upon corrosion on API 5L X-70 carbon steel coupon were investigated using a weight loss method, an open circuit potential method (OCP), and a potentiodynamic polarization curves method in anaerobic conditions. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were then used to determine the corrosion morphology in verifying the SRB activity and corrosion products formation. Results from the study show that the corrosion rate (CR) of weight loss method for the isolated SRB is recorded as 0.2017 mm/yr compared to 0.2530 mm/yr for ATCC 7757. The Tafel plot recorded the corrosion rate of 0.3290 mm/yr for Sg. Ular SRB and 0.2500 mm/yr forDesulfovibrio vulgaris. The results showed that the consortia of isolated SRB were of comparable effects and features with the single ATCC 7757 strain.

PENGARUH BASIC SEDIMENT AND WATER TERHADAP LAJU KOROSI PIPA X52 DAN A53 PADA MEDIA OIL SLUDGE.

ROTOR ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Naufan Arviansyah ◽  
Sumarji Sumarji ◽  
Digdo Listyadi Setyawan
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Low Carbon Steel ◽  
Measuring Method ◽  
Oil Sludge ◽  
Uniform Corrosion ◽  
Low Carbon ◽  
Weight Loss Method ◽  
Loss Method

This research have a purpuse to know corrosion rate in pipe X52 and A53 at oil sludge media caused BS and W. Corrosion is a damage of metal that occurs because reaction between metal with environtment and produce unwanted of corrosion product. Pipe X52 and A53 is a type of low carbon steel that use for fluid transportation system in industry. Oil sludge is a sediment of crude oil from main gathering storage and containing variouses elements. Oil sludge have a one of element is Basic Sediment and Water that is can make corrosion happen to distribution pipes. Measuring Method used in this research is weight loss method. The result of corrosion rate in Oil Sludge media containing 30,17% BS and W for pipe A53 is 1,64 x 10-2 mmpy and the result for pipa X52 is 2,47 x 10-2 mmpy. The result of corrosion rate in Oil Sludge media containing 60,67% BS and W for pipe A53 is 2,12 x 10-2 mmpy and for pipe X52 the result is 3,13 x 10-2 mmpy. The result of this research showed pipe A53 have more resistance than pipe X52. The corrosion is classified as uniform corrosion. Keywords : A53, Weight Loss, Oil Sludge, X52.

scholarly journals Synthesis of Water Soluble Chitosan Inhibitor from Shrimp Shells and its Corrosion Rate on Mild Steel in Acidic Solution

2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Nur Layli Amanah ◽  
Ika Dyah Widharyanti ◽  
Agung Nugroho
Keyword(s):  
Corrosion Rate ◽  
Inhibition Efficiency ◽  
Low Carbon Steel ◽  
Water Soluble ◽  
Low Carbon ◽  
Shrimp Shell ◽  
Weight Loss Method ◽  
Shrimp Shell Waste ◽  
Loss Method ◽  
Increasing Temperature

<span>Synthesis of WSCI (Water Soluble Chitosan Inhibitor) </span><span>from shrimp shell waste is carried out through demineralization, deproteination, and deacetylation processes. WSCI is obtained from monomer termination and H<sub>2</sub>O<sub>2</sub> assistance. WSCI was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and the degree of deacetylation was determined using the baseline method. The effect of adding WSCI to low carbon steel SS400 with a 1 M HCl corrosive environment was studied using the weight loss method at various concentrations and temperatures. The overall results of the research show that WSCI synthesis used in the prevention of corrosion have an inhibition efficiency of up to 74.6% at a concentration of 200 ppm at a temperature of 28<sup>o</sup>C. Inhibition efficiency and corrosion rate are known to increase with increasing WSCI concentration and corrosion rate decreasing with increasing temperature.</span>

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