The current research project focuses on radiant tubes as an example of essential and thermally highly stressed components in heat treatment plants. Radiant heating tubes separate the exhaust gas of the heat-releasing combustion from the furnace chamber atmosphere in which the material to be treated is located. As a result of the thermal load, radiant heating tubes sometimes undergo severe creep deformation. If a certain tolerance threshold concerning the deformation is exceeded, the radiant tube must usually be replaced or, if possible, turned by 180°. Such replacement or turning of the radiant tube requires a shutdown of the plant and thus a production stop with corresponding production losses and increased operating costs. Therefore, the current research project focuses on the influence of practice-relevant operating modes of radiant heating tubes on their service life.
As a basis for the intended preventive maintenance, the researchers investigate the behavior of relevant high-temperature alloys under exemplary, practice-relevant load profiles. As a result of the project, recommendations for action in the form of a comprehensive database and an extended calculator for the service life assessment of high-temperature materials under thermal cycling stress will be made available. Thus, different aspects of the operating mode of a plant – such as the on-off cycling of the burners and the change between different operating temperatures – can be optimized with regard to lifetime and energy efficiency and industry 4.0 concepts can be implemented. Outside the industrial furnace construction sector, for example, manufacturers of industrial and small burners, the chemical industry as well as companies in the thermal waste disposal sector can benefit from the results.