Materials used for high temperature applications are subjected to various types of degradation phenomenon such as high temperature corrosion, erosion-corrosion, overheating, solid particle abrasion, wear, etc. Boiler tubes used for super-heaters and re-heaters in steam-generating systems are subjected to erosion-corrosion at high temperature, resulting in tube wall thinning and premature failure. The present study investigates the high temperature erosion-corrosion resistance of D-gun sprayed coatings on "ASTM-SA210-GradeA1" boiler tube steel in actual industrial environment. SEM/EDAX, XRD and X-ray mapping analysis is done to reveal the microstructural and compositional features of coated boiler tube steel. The deposited coatings on Grade A1 steel exhibit uniform and dense microstructure. Thermogravimetric technique is used to investigate the erosion-corrosion behavior of uncoated and coated boiler tube steel at high temperature for 1000 hours. SEM/EDAX, XRD and X-ray mapping techniques were used to analyse the corrosion products.

Structural materials in many front-line high technology areas have to operate under extreme conditions of temperature, pressure and corrosive environment. So, Materials degradation at high temperatures is a serious problem in several high tech industries. Gas turbines in aircraft, fossil fueled power plants, refineries, and petrochemical industries, and heating elements for high temperature furnaces are some examples where corrosion limits their use or reduces their life, considerably affecting the efficiency. Corrosion causes plant shut downs, waste of valuable resources, loss or contamination of products, reduction in efficiency and costly maintenance in the present work, it was planned to study the behavior of boiler steels subjected to high temperature corrosion in boiler of thermal power plant. Selection of candidate material for the study was made after consultation with Guru Nanak Dev Thermal Plant, Bathinda (India). Thermogravimetric studies were done to understand the corrosion kinetics. Standard techniques such as Scanning Electron Microscope (SEM), Energy Dispersive X - Ray Analysis (EDAX) and X - Ray Diffractometer (XRD) were used to characterize the corrosion products.

Wear problem of grey cast irons selected as case study in this work is being faced in Brake Rotors, where abrasive and adhesive wear of these grey cast irons takes place due to the abrasive action. Although efforts have been made to reduce the friction coefficient and to increase the wear resistance of grey cast irons by varying alloying elements such as titanium yet there is little or no work on the use of coatings on various grades of grey cast irons used in braking rotors. The objective of the study is to develop the Detonation Sprayed wear resistant coatings Cylindrical pins of grey iron (GIHC and GI250) have been prepared. Three different coatings i.e. Stellite-21, Cr3C-25NiCr, and Al2O3-40TiO2 were deposited on end faces of these pins. Coatings were characterized using SEM/EDAX and XRD analysis. The wear testing on the uncoated as well as coated grey cast iron specimens was done with the help of Pin-on- Disk wear test rig. Wear data was collected for three loads i.e. 40N, 50N, 60N. The worn out specimens were characterized by SEM / EDXA analyses.

Hardfacing by welding is the most economic way to enhance the life of the components which are exposed to high abrasion environment. Chromium rich electrodes are widely used due to their low cost. It is planned to study the effect of carbon and chromium over a wide range, on the resultant microstructure as well as wear behavior of the deposited layers, of the bottom plate of concrete mixer used in ready mix concrete plant.Six types of iron-based hardfacing electrodes with a wide range of C (0.6-5% by wt.) and Cr (3.5-35% by wt.) were selected to deposit, by the manual metal arc welding process on the mild steel plate of concrete mixer. The abrasive wear responses, hardness and the microstructures were compared with that of mild steel.Abrasion tests were carried out in a sliding wear abrasion test machine. surface analysis were made using SEM-EDAX, XRD Analysis.Field test was performed, by hardfacing on the actual size mild steel plate.The extent of improvement in wear performance of mild steel due to all hardfacing alloys is quite appreciable as compared to mild steel. Further the life of hardfaced plate was enhanced by 3.11 times compared to mild steel plate resulting net cost

it is now generally accepted practice to apply coatings to components in fossil fuel energy processes to protect against surface degradation processes such as wear, oxidation, corrosion and erosion.The nanostructured thin TiAlN and AlCrN coatings deposited by PVD technique and the conventional thick TiAl and AlCr coatings deposited by Plasma Spraying and further gas nitrided; were selected for the present work. After conducting the various experiments on uncoated and coated alloys (total 16 substrate-coating combinations along with the bare alloys) in lab and in actual industrial environment which includes the characterization of the nanostructured and conventional TiAlN and AlCrN coatings on selected Fe-based alloys and their behavior when exposed to high temperature oxidation studies in air, molten salt environment and in a coal fired boiler of a thermal power plant, erosion studies in simulated coal-fired boiler environment; the coating-substrate combinations which are found successful in protecting the substrates from oxidation, hot corrosion, erosion and wear are proposed to provide thermal insulation, corrosion and wear resistance to the components in chemical process plants