Yogesh Y. Mahajan

Failure Analysis of Bed Coil Tube in an Atmospheric Fluidized Bed Combustion Boiler

The Atmospheric Fluidized Bed Combustion Boilers have advantages as compared to conventional coal fired boilers in respect of heat transfer, SOx, NOx, emissions and efficiency. In the present study, the failure analysis of bed coil tube, used in atmospheric fluidized bed combustor was studied. The failure studies included physical, chemical and metallurgical analysis and the results analyzed reveal that the failure is typically due to caustic gouging. The cause of failure has further been substantiated using scanning electron microscopy with energy dispersive X-ray analysis as well as X-ray diffraction analysis.

Effect of Temper Conditions on Abrasive Wear Behavior of AA7010 Alloy

AbstractThe 7xxx series alloys are used mainly in transportation industries for manufacturing vehicles due to their unique properties such as high specific strength and specific stiffness. Wear of the engine component is one of the major problems in vehicle manufacturing industries. This paper investigates wear behavior of AA7010 alloy used in transportation industries. The Al–Zn–Mg–Cu alloy solutionized and aged at various temper conditions was studied for wear using pin-on-disc machine. The characterization of the wornout surface was carried out. To study the wear mechanism, wornout surfaces were examined under scanning electron microscope. From the analysis, it was concluded that change in specific wear rate of AA7010 alloy was associated with change in hardness and microstructural constituents. Specific wear rate of peak aged and retrogression reaged RRA treated alloy were comparable. Maximum hardness in peak aged and retrogression reaged (RRA) treated alloy resulted in minimum specific wear rate as compare to solution treated and overaged alloy.