On the influence of temperature on the subgrain size

In the alloy Fe–3wt.% Si, the influence of temperature on the deformation substructure formed in creep at 823–973 K has been investigated. The overall `athermalʹ relation combining data obtained at different testing temperatures was splitted to several `isothermalʹ relations whose parameters can be correlated with temperature. A detailed investigation by optical and electron microscopy and the image analysis of microstructures in specimens deformed at different temperatures at the same applied stress confirm the decrease of the subgrain size with increasing temperature but did not reveal any pronounced change of the subgrain shape. The effect of temperature on the subgrain size is discussed as a real effect and as an artefact effect which might be due to a temperature dependence of the pitting process.