Analysis of Ultrasonic Fatigue on an Austenitic Steel at High Temperature

FEDERICO J. CAVALIERI; CLAUDE BATHIAS; NICOLAS RANC; ALBERTO CARDONA

Universidad Nacional de San Luis

Congreso; ENIEF 2008 XVII. Congreso sobre Métodos Numéricos y sus Aplicaciones; 2008

Asociación Argentina de Mecánica Computacional

In this work, an ultrasonic fatigue technique is presented to study the fatigue behavior on anaustenitic steel at high temperatures under fully reverse loading (R=-1) in the lifetime range from 1e5 to 1E9 cycles. This material is employed in internal combustion engine valves. To carry out the fatigue tests at high temperatures, an induction coil heating equipment was employed to achieve temperatures as high as 600ºC and 700ºC on the specimens. Since Young modulus is a function of temperature, its value changes when the specimen is heated. We analyzed with a numerical methodology (finite element method, FEM), the effects of the variation in the Young modulus due to temperature from the measurement of the ultrasonic resonance frequency. Thermal, thermo-mechanical and modal analysis by FEM was used for designing the specimens at test temperatures. The commercial software was employed for the numerical simulations.