Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : corrosion rate

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.

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.