Influence of Thermal Fatigue on Degradation Behaviour in Surficial Layers of Selected Glass Industry Parts

AbstractThe given paper deals with evaluation of the boundary state of degradation of materials, which are exposed to high temperature variation. A significant operating wear appears at these materials. The work results from description of possible boundary states which are not meeting requirements for the final product and they are also connected with the root cause of the wear origin. The experiment was connected with evaluation of prepared microstructures of initial and operating material in that connection with fractography. Based on the fact that chemical analyse of this material shows inconsistency in chemical composition in comparison with declared material, the attention was given to influence of additive and alloying components. The study of undesirable phases, which occur in the microstructure, proves the inappropriate choice of the initial material. On the basis of experiments and obtained results, recommendations, which might be used for prediction of appearance of boundary states of microstructure during operation, were proposed. As long as the chemical composition is not fulfilled, a presence of greater amount of non-metallic elements (sulphur, oxygen, nitrogen, etc.) is observed. These elements are bound with chromium, molybdenum, manganese, nickel and other alloying elements, with which create chemical compounds (in metallurgy, they are designated as inter-metallic or intermediary phases)