Study on corrosion rate of carbon steel pipe under turbulent flow conditions

Abstract

The effect of time (or corrosion products formation) on corrosion rate of carbon steel pipe in aerated 0.1 N NaCl solution under turbulent flow conditions was investigated. Tests were conducted using electrochemical polarisation technique by determining the limiting current density of oxygen reduction in Reynolds number (Re) range of 15 000 to 113 000 and temperature range of 30-60 • C. The effect of corrosion products formation on the friction factor increase was studied and discussed. Empirical correlations for limiting current density as a function of Re were obtained at various solution temperatures for clean surface and for corroded surface. It was found that formation of corrosion products with time decreases the corrosion rate at low Re and temperature, while it increases the corrosion rate at high Re and temperature. As the corrosion products formed the surface roughness increased leading to increase the friction factor depending on temperature, Re, and corrosion rate.On a analysé l'effet du temps (ou la formation de produits de corrosion) sur la vitesse de corrosion d'un tuyau d'acier au carbone dans une solution 0.1 N NaCl aérée dans des conditions d'écoulement turbulent. Des essais ontété réalisésà l'aide de la technique de polarisationélectrochimique en déterminant la densité de courant limité de la réduction de l'oxygène dans l'écart de nombres de Reynolds de 15000à 113000 et dans l'échelle de température de 30 • Cà 60 • C. L'effet de la formation de produits de corrosion sur l'augmentation du facteur de frottement aétéétudié et discuté. Les corrélations empiriques pour la densité de courant limité comme fonction du nombre de Reynolds ontété obtenuesà diverses températures de solution pour une surface propre et une surface corrodée. On a découvert que la formation de produits de corrosion avec le temps réduit la vitesse de corrosionà une température et un nombre de Reynolds bas tout en augmentant la vitesse de corrosionà une température et nombre de Reynoldsélevés. Pendant que les produits de corrosion se formaient, la rugosité de la surface augmentait, ce qui a menéà une augmentation du facteur de frottement selon la température, le nombre de Reynolds et la vitesse de corrosion.

Oil fouling in double‐pipe heat exchanger under liquid‐liquid dispersion and the influence of copper oxide nanofluid

“…This means that the deposition of oil on the surface is slight and does not restrain the heat transfer. The decrease of R f with time has also been noticed by Emani et al and a negative fouling resistance has also been reported by several workers for scale fouling and for crude oil fouling . The case of negative fouling resistance has been studied and discussed in detail in the work of Crittenden and Alderman .…”

“…This causes and increase in the heat transfer coefficient and thus a reduction in the fouling thermal resistance. It was found by several previous workers that the increased roughness due to fouling causes an increase in the heat transfer coefficient and a reduction the fouling resistances …”

Galvanic Corrosion of Copper / Nickel-Chrome Alloy in an Agitated Sulfuric Acid Solution

“…This is due to the increased anodic polarization and a possibility of passivation. The clear increase of the corrosion rate with temperature is ascribed to two main reasons [5,8]: the first one is the increased anodic dissolution reaction of metal due to the decrease in activation energy of anodic reaction. The second one is the increased oxygen diffusivity that leads to increase the arrival of oxygen to the metal surface and hence enhance the corrosion.…”

“…During each experimental run, the variation of galvanic potential with time was measurement by using Saturated Calomel Electrode SCE bridged by a Luggin capillary at a distance of 1-2 mm from the working electrode [8] connected to personal computer for data recording. The specimens were immersed in the acid solution for 1 h. During this time period, the galvanic current and galvanic potential were measured with time.…”

Galvanic corrosion of aluminum–steel under two-phase flow dispersion conditions of CO2 gas in CaCO3 solution

“…CS, leading to a decrease in the arrival of the cathodic species to the CS. Therefore, the oxidation rate of CS is decreased causing a decrease in I g (Slaiman and Hasan, 2010). An XRD analysis of the formed corrosion product layer showed that this layer consisted mostly of iron carbonate scale (FeCO 3 ).…”