Corrosion of carbon steel in formic acid as an organic pollutant under the influence of concentration cell

Abstract

The presence of contaminants in water even in small amounts can cause considerablecorrosion damages of metals. This is due to free corrosion effect or the formation ofconcentration cell of pollutants resulting in a galvanic effect. The current work was devotedto study the effect of formic acid (CH2O2) as an organic pollutant on the corrosion rate ofcarbon steel under different operating conditions. It includes an investigation of galvaniccorrosion caused by the establishment of concentration cell of formic acid under differentoperating conditions. The ranges of operating parameters were formic acid concentration of10-4 - 10-5 M and temperature of 32 - 50 °C. The results showed that increasing formic acidconcentration to 10-4 M leads to an increase in the corrosion rate by up to 7.6 times that inthe water of 0.1N NaCl. In addition, the corrosion rate in each terminal in concentrationcell also increased by up to 2.3 times. Pumping of air in formic acid solution led to aconsiderable increase in the corrosion rates and enhances the concentration cell effectwhich increases the galvanic currents. High increase of corrosion rate was noticed bypumping the air at high temperature reaching up to 4 times depending on temperature. Ingeneral, the galvanic currents were high initially and decreased with time due to theformation of corrosion product layer. The increase in temperature from 25 to 50 oC causedan increase in the galvanic corrosion rate reached up to 2 times in formic acid solution. Inaddition, the galvanic currents were noticed to decrease with temperature while thecorrosion rate of each terminal was increased.

Effect of heat and mass transfer on corrosion of carbon steel in a crude oil medium using corrosion inhibitors sodium nitrate and castor oil under different circumstances

“…It is also directly proportional to the increase in the carbon steel corrosion rate, as illustrated in Table 3. This is in accordance with what numerous researchers have observed [19,20]. From Figures (8) and ( 9) and Tables ( 4) and ( 5), it can be seen that the inhibitor concentration of both the sodium nitrate and castor oil is inversely proportional to the carbon steel corrosion rate, given that the higher the inhibitor concentration, the lower the corrosion rate and vice versa.…”

Evaluation of Corrosion Inhibition of Carbon Steel in Crude Oil by Using Different Green Corrosion Inhibitors and Various Rotation Speeds

“…This is caused by the rise of the oxygen transferred on the surface of c-steel, being a main factor for corrosion. These results are almost similar to conclusions of previous students [19]. From Figures (5) to (8) and Table ( 4), it can be observed that the inhibitors concentration of castor oil, flaxseed oil, sunflower oil and corn oil is inversely proportional to the corrosion rate of c-steel, where the corrosion rate of metal increases as concentration of the inhibitor decreases and vice versa.…”

“…Both Table (3) and Figure (3) confirm that the corrosion rate of c-steel increases with the increasing of rotational speed, and this occurs because of the removal of the protective surface films due to the high flow of velocity, leading to an increase in the diffusion of oxygen on the metal surface, causing meanwhile a decrease in the boundary and diffusion layers [19].…”

All-laser route for anti-fouling superhydrophobic albronze fabrication and non-contact microbial detection

“…Biofouling leading to clog and operation failure are one of the severe challenges underwater components are facing today. Macrobiotic reproduction changes the local micro-environment and the surface state of the albronze components, and subsequently accelerates the corrosion at the metal/water interface [5,6]. Establishing a barrier against biofouling for underwater facilities is hence of great significance.…”