Digital Quality Control of Thermochemical Processes - Industry 4.0

The digital integration of heat treatment into the process chain allows for new perspectives for efficient industrial production. The buzzword “Industry 4.0” summarizes new digital approaches to make the process chain more flexible, more efficient and more transparent. Besides the digital integration of heat treatment with the process steps of soft- and hard-machining („smart factory“), predictive maintenance („condition monitoring“) und improved transparency of manufacturing („traceability“), the topic of „Digital Quality Control” is shifting more and more into focus. This “Digital Quality Control” can be an important step towards a better defect prevention and thus more robust process chains. Yet the discussion of “Digital Quality Control” is rather abstract. This paper shows practical implementations of “Digital Quality Control” in heat treatment. During the process of “Low Pressure Carburizing (LPC)” the main process parameters are continuously surveyed with a so-called “Process Monitoring system“. In case of a significant deviation of the actual from the set value, the surveyed charge is labelled with a “Red Flag“ and then sent automatically to the quarantine area. Furthermore those “Red Flag“-notifications are being sent from the furnace to the factory ERP-System which is linked digitally to the quality lab. As soon as the technician in the quality lab starts to analyze this load, he gets digitally notified that this load has been labelled with a “Red Flag” and subsequently he initiates an in-depth-testing of the load. The paper demonstrates with concrete examples, -which process parameters are being surveyed, -how to define the thresholds for the “Red Flags” and -how to implement the digital integration between the furnace, the ERP-System and the quality lab.