Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : carbon steel

Nano Ferrites as Corrosion Inhibitors for Carbon Steel in Local Iraqi Bentonite Mud

N.A. Al-Rubaiey; F.S. Kadhim; A.A. Ati

Engineering and Technology Journal, 2017, Volume 35, Issue 8, Pages 849-855

Corrosion processes are accountable for serious losses in the oil industry. Although organic and inorganic materials and mixed materials inhibitors have been used for a long time to control or reduce corrosion. Using nano-materials as inhibitors has gained an increasing applications role because of their exceptional properties. Nano materials are good corrosion inhibitors because they possess many advantages such as high efficiency of inhibition, low cost, minimum toxicity and effortless production. This work examines the use of nano-materials as inhibitors to prevent corrosion of carbon steel in drilling mud. Anti-corrosion properties of zinc and nickel ferrite nano materials (ZnFe2O4, Zn0.6Ni0.4Fe2O4) have been investigated over carbon steel in local Iraqi bentonite mud as a source of the corrosion. It has been found that under the given conditions, ferrites act as efficient corrosion inhibitors of carbon steel.

Corrosion Inhibition of Steel (St 44-2) by Pomegranate Shells in Acidic Medium

H.A. Abdullah

Engineering and Technology Journal, 2017, Volume 35, Issue 4, Pages 399-405

Pomegranate shells were investigated as green inhibitors for steel 44-2 in 0.1M HCl at various temperatures (30, 40, 50, and 60) °C using electrochemical technique. Five concentrations of inhibitor were added 4, 8, 12, and 16 ppm. Corrosion tests were performed by Potentiostat at 5 mV.sec-1 scan rate and the data measured by Tafel extrapolation method such as Tafel slopes, corrosion current density and corrosion potential. Inhibition efficiencies were calculated and indicated that 8 ppm was the best concentration for inhibition especially at 60oC, where was 96.47%. Pomegranate Shells behaves as anodic inhibitor type and obeys Langmuir adsorption isotherm. The equilibrium constant of the adsorption-desorption process and the apparent free energy of adsorption confirm the physicsorption of Pomegranate shells. FTIR spectroscopy was used to test film formed on steel surface compared with FTIR spectrum of Pomegranate Shells. These spectra confirm the formation of Fe2+Pomegranate shells complex.

Galvanic Corrosion of Carbon Steel –Copper in Aerated H2SO4 Under Agitation Conditions

Muayad F. Hamad; Huda D.Abdul Kader; Basim O. Hasan

Engineering and Technology Journal, 2015, Volume 33, Issue 9, Pages 2107-2118

Galvanic and free corrosion experiments on carbon steel-copper couple in 3% H2SO4in the presence of NaCl salts were carried out under different operating conditions. The effect of temperature, agitation speed, and air bubbling (O2 concentration) on the free and galvanic corrosion was studied and discussed. The galvanic corrosion was investigated by both weight loss method and by determining the galvanic currents using zero resistance ammeter (ZRA). The results revealed that increasing temperature leads to increase the galvanic corrosion rate and also the free corrosion rate of each metal. Increasing agitation velocity enhanced the galvanic corrosion rate in a manner depending on temperature. The presence of air bubbling increased the corrosion rate and galvanic currents at low air pumping rate, while, at high pumping rate, air bubbling decreased the corrosion rate.

The Influence of Microstructure on the Corrosion Rate of Carbon Steels

Sami I. Al-rubaiey; Eman A. Anoon; Mahdi M. Hanoon

Engineering and Technology Journal, 2013, Volume 31, Issue 10, Pages 1825-1836

This paper presents the influence of carbon steel microstructure on the corrosion rates. Four types of microstructures have obtained by quenching and tempering and iso-thermal annealing. These microstructures are:
banded ferrite/pearlite microstructure, fine ferrite/pearlite microstructure, coarse ferrite/pearlite microstructure and tempered martensite microstructure.
General corrosion and localized corrosion (penetration rates) were determined via mass loss and optical microscopy. The different microstructures of steels investigated in this paper revealed corrosion rate variations of 0.8– 3.2 mm y-1 and 3.3–6.4 - mm y-1 for the general and localized forms, respectively. The corrosion stability of the various microstructures may arise from variations of phases within the steel. A banded ferrite/pearlite microstructures have worse general corrosion properties, while tempered martensite worse microstructures have localized pitting corrosion properties. Coarse ferrite/pearlite microstructures have better localized pitting corrosion resistances compared to others investigated microstructures This paper has demonstrated that, microstructure is an important consideration when selecting carbon steel for an industrial corrosion resistance application.

The Effect of Different Operating Parameters on the Corrosion Rate of Carbon Steel in Petroleum Fractions

Nagham Salman Hassan

Engineering and Technology Journal, 2013, Volume 31, Issue 6, Pages 1182-1193

The corrosion in petroleum pipelines was investigated by the studying the corrosion of carbon steel in crude oil and refined petroleum products which include gasoline, kerosene, and gas oil. Weight loss method was used in which test specimens of carbon steel, with a known weights, were immersed in the test media for a total exposure time of 60 days. The weight loss was measured at an interval of 10 days and the corrosion rate was determined. The results showed that corrosion rate are highest for gasoline followed by kerosene, gas oil and crude oil, in a decreasing order. The observed pattern in the corrosion behavior is consistent with the density and weight percent of hydrogen in the hydrocarbon products. The corrosion rate increases with decreasing density and increasing weight percent of hydrogen. Experiments were carried out at different temperatures (30, 60, 90 and 120oC) at a constant partial pressure of CO2 (50psi) in 3.5% NaCl solution. The results indicated that as partial pressure of CO2 and temperature increase, corrosion rate increases due to due to continuous dissolution of iron ion and formation of weak carbonic acid. The weak carbonic acid dissociates into carbonate and hydrogen ion, which increases the cathodic reaction on the metal surface.The presence of small amount of H2S (0.4 ppm) increases the corrosion rate significantly.

Study the Microbiologically Influenced Corrosion of Carbon Steel

Zuheir T.Khulief.Al-Tai

Engineering and Technology Journal, 2011, Volume 29, Issue 15, Pages 3141-3157

The main objective of this study was to evaluate the microbiologically
influenced corrosion of carbon steel in water, samples of water taken from Al-Hilla rivers and distill water (control medium ). Corrosion analyses by using (Liner polarization tafel test; weight loss method ; microstructure examination , surface roughness test and X-Ray diffraction analysis) and microbiological analyses by using
(Isolation and identification by using appearance factors microscopic ,culturing factors and biochemical tests for biofilm of corrosion product) are used in this study. The result of corrosion analyses shows the corrosion rates of carbon steel in rivers water are more than that in control water, the microstructure examination and surface roughness tests show increase in roughness of surfaces which are
under the corrosion medium (rivers water) compared with control medium. The result of microbiological analyses shows the slides that made from the biofilm (product of corrosion) under microscopic appear small bacilli negative gram strain (G-ve) bacteria, where as culturing test shows small colonies with 2.5ìm in diameter of bacteria have mucin appearance and green pigments as well as the result from
biochemical tests; these facts indicate that Pseudomonas aeruginosa bacteria are correlated with the type of corrosion occurring in the carbon steel in the rivers water.

Effect of the Heat Treatments on Corrosion and Erosion-Corrosion for Carbon Steel

Muna k.Abbass; Mohammed A.Ahmed; Makarem Hazem

Engineering and Technology Journal, 2011, Volume 29, Issue 13, Pages 2706-2722

The aim of present work is to study the effect of different heat treatments [full annealing ,normalizing ,and hardening and tempering at (300C° ,600C°)] on general corrosion and erosion-corrosion for a carbon steel type (C35) in 3.5wt% NaCl solution as corrosive medium for general corrosion while in erosion-corrosion ,slurry with 1wt% SiO2 sand was added to 3.5wt% NaCl solution as the erodent. The experimental work tests were done using special device which was designed and manufactured according to (G73 ASTM) using traditional weight loss technique to measure weight loss rate or corrosion rate in (gmd) unit.
It was found that the general corrosion rates for all heat treated specimens were lower than erosion-corrosion rate. The erosion-corrosion rate of specimen which was quenched and tempered at 600C° was found smaller than other heat treated specimens The normalizing heat treatment of low carbon steel improves the general pure corrosion resistance after immersion 20 day in 3.5 wt% NaCl solution.

Effect Of Mixing Speed And Solution Temperature On Cathodic Protection Current Density Of Carbon Steel Using Magnesium As Sacrificial Anode

K. T. Rashid

Engineering and Technology Journal, 2009, Volume 27, Issue 8, Pages 1640-1653

In present work, The corrosion behavior of carbon steel in sodium chloride (NaCl)
solution with different concentrations was studied .Effects of mixing speed (0 to 2220) r.p.m
and the solution temperature (25, 35, 45, 55, 65)0c on cathodic protection current density were
studied, that would provide a full cathodic protection for tube metal specimen of carbon steel
immersed in 3.5% NaCl solution by sacrificial anode method using magnesium (Mg) as
sacrificial anode.
The results show that the concentration of sodium chloride in the electrolyte is an
important factor in determining corrosion rate, 3.5 % concentration of sodium chloride gives
maximum rate of corrosion. In addition, it has been found that the cathodic protection current
density showed sharp increasing with mixing speed. The results have showed also that the
cathodic protection current density increased with increasing the solution temperature and
shifts the protection potential to high negative value.

An Investigation of the Inhibition of the Oxygen Reduction Reaction at a Rotating Cylinder Electrode under Isothermal and Controlled Conditions of Heat and Mass Transfer

Shatha. A. Sameh; Sadiq. H. Alwash

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 930-941

The inhibition of the oxygen reduction reaction on a carbon steel rotating
cylinder electrode in naturally aerated 600 ppm Cl- solution was studied using an
optimum inhibitor blend, i.e., Sodium Nitrite (SN): Sodium Hexametaphosphate
(SHMP) = 500:100 obtained via a weight loss technique. Potentiostatic technique, then,
was applied at different bulk temperatures and various flow rates using un-inhibited and
inhibited solutions under isothermal and controlled conditions of heat transfer.
In an un-inhibited solution and under isothermal conditions, with limiting conditions of
concentration polarization, the limiting current density of oxygen reduction reaction is
flow and temperature dependent. The charge transfer of the oxygen reduction reaction is
a 4 electron process in the range of bulk temperature employed from 303 to 323 K.
Under heat transfer conditions, the charge transfer is still 4 electron process up to 336 K
interfacial temperature, above which the contribution of the 2 electron process appeared.
Moreover, the limiting current density values of the oxygen reduction reaction in
inhibited solutions is much lower than those under identical conditions in un-inhibited
solutions. This confirms the inhibition of the cathodic reaction, i.e., the oxygen
reduction reaction under isothermal and heat transfer conditions, due to SHMP.