Damage and fracture of heat resistance steel under cyclic thermal loading

It was found that under the thermal cycle loading two interrelated process take place. In the material inner layers redistribution of dislocation and formation of sufficiently stable structure with the less dislocation density take place. Thus, the level of micro-stresses in the metal on the specimens surface and micro-hardness increases, which results in the elasticity exhaustion decrease of the metal micro-plastic deformation resistance. Localization of the micro-plastic deformations causes accumulation of the damage and initiation of microcracks.