DURING COMBUSTION in the gas turbine, sulfur from the fuel reacts with sodium chloride from ingested air at elevated temperatures to form sodium sulfate. The sodium sulfate then deposits on the hot-section components, such as nozzle guide vanes and rotor blades, resulting in accelerated oxidation (or sulfidation) attack. This is commonly referred to as “hot corrosion.” Sulfur in the fuel is gen...

a constant problem in the production, maintenance, and use of agricultural pesticides, is their physical-chemical corrosive properties in contact with machines and equipment. the present study attempted to increase the corrosion resistance of steel parts to agricultural pesticide with the application of appropriate thin tio2 nanoparticle coatings. this coating was applied on mild steel coupons ...

Corrosion behavior of Ni20Cr coatings deposited by HVOF (high velocity oxygen-fuel) process was evaluated in ZnCl2-KCl (1 : 1 mole ratio) molten salts. Electrochemical techniques employed were potentiodynamic polarization curves, open circuit potential, and linear polarization resistance (LPR) measurements. Experimental conditions included static air and temperatures of 350, 400, and 450°C. 304...

The damage caused by corrosion in chemical process installations can lead to unexpected plant shutdowns and the leakage of potentially toxic chemicals into the environment. When subjected to corrosion, structural changes in the material occur, leading to energy releases as acoustic waves. This acoustic activity can in turn be used for corrosion monitoring, and even for predicting the type of co...

The crevice correction is a common type of localized corrosion which costs multibillion dollar losses in many different fields including aerospace, automobile, and building structures. The crevice geometry can easily catch moisture and impurity which accelerates the chemical corrosion. It is one of the dangerous corrosions that can cause sudden failure of the products and involve the human inju...

Microbiologically influenced corrosion is a complex type of environmentally assisted corrosion. Though poorly understood and challenging to ameliorate, it is increasingly appreciated that MIC accelerates failure of metal alloys, including steel pipeline. Historically, this type of material degradation process has been treated from either an electrochemical materials perspective or a microbiolog...

Microbiologically influenced corrosion (MC) of steel has been attributed to the activity of biofilms that include anaerobic microorganisms such as iron-respiring bacteria, yet the mechanisms by which these organisms influence corrosion have been unclear. To study this process, we generated mutants of the iron-respiring bacterium Shewanella oneidensis strain MR-1 that were defective in biofilm f...

In recent times, the Risk Based Inspection (RBI) engineering approach has been extensively used in the Oil and Gas industries to maintain the plant integrity and thereby continual operation of the assets. Sometimes, the type of corrosion risk and its consequences can be either overlooked in the RBI approach due to inadequate knowledge of the metallurgy, chemical reactions, resulting corrosion m...

calcareous deposits formed on the part of steel that cathodic reactions occur on their surface. the purpose of this research is an investigation of the effect of potential on crystal form of the calcareous deposits and effect of them on the corrosion resistance of the mild steel in natural seawater. the electrochemical tests such as impedance and polarization tofel tests were used in order to i...