Fatigue life studies on induction hardened in718 Alloy for gas turbine applications

Abstract

Fatigue Life Studies on Induction Hardened IN718 Alloy for Gas Turbine Applications newlinePh.D Thesis, Visvesvaraya Technological University, Belagavi i newlineAbstract newlineA gas turbine is a type of internal combustion engine that converts the energy from burning newlinefuel into mechanical energy. Gas turbines are known for their high power to weight ratio, newlinemaking them suitable for aviation and power generation applications. In the aviation industry, newlinegas turbines are commonly used in jet engines to provide the thrust necessary for flight. They newlineare preferred due to their ability to operate at high altitudes and speeds efficiently. Generally, newlinethe gas turbines experience failure in their service on account of high thermal fatigue. Thermal newlinefatigue occurs when materials are subjected to cyclic temperature changes, leading to newlinemechanical stress and potential failure. Turbine blades and rotor discs are especially susceptible newlineto thermal fatigue failure due to the combination of high temperatures and cyclic stresses they newlineexperience during operation. To mitigate gas turbine failure due to high thermal fatigue the use newlineof high temperature resistant materials can improve the thermal fatigue resistance of turbine newlinecomponents. newlineResearch and development toward the growth of advanced materials for gas turbine engine newlineapplication is the point of study for the research. The Inconel alloy 718 (IN718) is commonly newlineused as a component in industrial gas turbines due to its excellent corrosion resistant and high newlinetemperature properties. This research work presents a comprehensive investigation of the newlinehardness, microstructure, X-ray diffraction (XRD), Energy Dispersive X-ray spectroscopy newline(EDS), tensile behavior, low cycle fatigue (LCF) response, and fracture characteristics of both newlineinduction hardened and unhardened Inconel alloy 718 for gas turbine applications. The study newlineaims to understand the material properties, mechanical behavior, and fatigue performance of newlinethe Inconel alloy 718 under room temperature and elevated temperature conditions (800°C). newlineAn ingot of c