Evolution of substructure in high-temperature creep of an iron-silicon alloy

The paper investigates an evolution of dislocation substructure in the cour se of creep with the aim to illustrate some aspects which can be seen in a larger field of substructure and can be derived from a statistical treatmen t of a greater sample of subgrains. The iron-silicon alloy was chosen as ex perimental material for the ease of visualization of substructures by etch pitting. The evolution of substructure was investigated on twelve specimens subjected to creep testing under identical conditions (stress and temperat ure), interrupted in chosen points of the creep curve. The micrographs obta ined by metallographical microscopy were subjected to image analysis. The e volution of the mean subgrain size can be modelled as a superposition of a subboundary creation and a subgrain growth.