The Influence of the High Temperature Oxidation Regime on Residual Stresses in Oxide Scales on Fecral-Type Alloys

The alumina-forming FeCrAl-type commercial alloys manufactured in different ways, conventional melting (Kanthal AF),  mechanical alloying (MA956) and powder metallurgy (Kanthal APM), were oxidized at 1100⁰C, in air for 5 hours under isothermal and thermal cycling conditions. Subsequently, after final cooling down the samples to the room temperature, the residual stresses in oxide scales as well at their phase composition and morphology were determined using Photoluminescence Spectroscopy and/or Scanning Electron Microscopy.

Different residual stresses were found in scales growing on various materials, under different regimes. Moreover, they depended on the region of the scale. These differences are discussed in terms of the response of the scale-substrate system to growth, structural and thermal stresses.