Creep Deformation Behavior of Heating Filaments in High Temperature Applications

B. Valentini [1],
[1] Plansee SE, Reutte, Austria
Published in 2015

Resistive heating filaments used in high temperature applications at 2000°C and above are often made of refractory metals. The lifetime of such filaments is mainly limited by creep deformations which can in the worst case lead to a short circuit between filaments and other furnace components. With the aid of COMSOL Multiphysics software, the time-dependent creep deformation behavior of a heater assembly with different shapes and arrangements of heating filaments is studied. In the numerical computations thermally induced stresses as well as electromagnetically induced Lorentz forces are considered. The creep deformation behavior is accounted for by a temperature and stress dependent creep model for isotropic metals under secondary creep.