The use of the finite element method to locate the places of damage occurrence in elements of technological equipment in carburizing furnaces

In the article, the stresses occurring in the basic pallet used as a carrier for elements subjected to the carburizing process were determined by the finite element method in the Ansys program. The calculations were performed for two models of the pallet. The first model includes a pallet that is free to deform during heating and cooling. In the second model, part of the pallet was covered with insulating material in order to force its uneven heating, which corresponds to the actual operating conditions. It has been shown that in both model cases the stress state is favourable for the formation of cracks. Based on the inspection of the basic pallets withdrawn from use, it was confirmed that the adopted numerical calculation method for a pallet with insulation was sufficient to locate the places where damage occurred at the element design stage. The conducted research is an introduction to further work on the influence of macro-stresses on the destruction of charge carriers used in heat treatment furnaces. At the next stage, a design solution will be proposed that will reduce the susceptibility to cracking at the corners of the basic pallet. An analysis of the stress state in the pallet covered with the charge during heating and cooling will be performed in order to indicate the stage of the thermal cycle responsible for the cracking of the charge carriers on a macro scale.