A comprehensive predictive corrosion model incorporating varying environmental gas pollutants applied to wider steel applications

Abstract

A comprehensive model has been developed to predict uniform corrosion rate of structural steel under the effect of low pH conditions for example acid rain. Acid rain is mainly caused by emissions of sulfur dioxide (SO 2 ) which reacts with the water droplets in atmosphere to produce acidic solution which is the primary cause of corrosion of steel structures such as bridges, and weathering of stone buildings and statues. A five-stage division was applied to mathematically describe the model as: (i) the growth rate of air-suspended water droplets (i.e. moisture) depending on the condensation/evaporation rate, (ii) the absorption of gas phase SO 2 in the droplets forming bisulfite HSO 3 − ions, (iii) the coalescence of these SO 2 absorbed water droplets under the effects of wind speed and gravity, (iv) the deposition rate of SO 2 absorbed droplets on steel substrate depending on the inclination and azimuth angles of steel surfaces and, (v) the corrosion rate of steel due to the deposition of these SO 2 absorbed droplets. The incorporation of all the above stages develops a comprehensive corrosion prediction model which not only includes the electrochemical parameters but also large number of physical, environmental and material parameters. Experiment was performed to analyse the corrosion rate of steel samples by exposing them to moist SO 2 corrosion test. A comparative analysis between the model predictions and experimental results was performed to verify the reliability of model. The predictive trends of corrosion rate of steel were also generated for different values of temperature, relative humidity, and SO 2 mole percentage.

Analyzing and Modelling the Corrosion Behavior of Ni/Al2O3, Ni/SiC, Ni/ZrO2 and Ni/Graphene Nanocomposite Coatings

“…Consider a composite coating which has debonded from the stress-free substrate; the coating will reach its minimum energy after relaxing and attaining equilibrium. There are two types of relaxation processes, including normal and parallel relaxation [ 9 , 36 ]. The normal relaxation leads to the creation of an eigenstress in the surface layer, while the normal relaxation leads to creation of a stress (or initial strain ) in the core to balance the surface stress.…”

“…Khan-Nazir [ 6 , 7 ] suggested that electrochemical reactions on metal coating surfaces are stress-dependent. Sometimes, both mechanical and electrochemical effects, coupled together, result in the modified corrosion rates of the nanocoating compared to its stress-free state [ 8 , 9 , 10 ]. Therefore, it can be established that the size-dependent electrochemical properties of nanocoatings would lead to size-dependent surface stress [ 11 , 12 ].…”

Electrochemical Study of Polymer and Ceramic-Based Nanocomposite Coatings for Corrosion Protection of Cast Iron Pipeline

“…A huge amount of resource and effort is continually dedicated to increasing the service life of components since corrosion causes significant loss in terms of costs and most importantly in human life [ 1 ]. Many techniques are used for protecting the structures against corrosion: corrosion inhibitors [ 2 , 3 ]; cathodic and anodic protection [ 4 , 5 ]; design modification, alteration with environment and most importantly changing the material which is probably more corrosion resistant e.g., stainless steel [ 6 ]. Application of various types of protective coatings is another popular method for protecting metals from aggressive corrosion reactions [ 7 , 8 ].…”

High-Performance Anticorrosive Polyester Coatings on Mild Steel in Mixed Acid Mixtures Environments

“…Corrosion is probably one of the most concerning issues that is faced in practical applications, thus di erent research strategies being added throughout the globe for the sole purpose of protecting di erent material from corrosion in various areas of applications. Many techniques are being used for protecting the structures from corrosion by adding corrosion inhibitors [4,5], by applying cathode and anode protection [6,7], design modi cation, alteration with environments, and most importantly changing the material which is more corrosion resistant, for example stainless steel [8]. Application of various types of protective coatings is another popular method for protecting metals from aggressive corrosion reactions [9,10].…”