The heating curve describes the temporal progression of the temperature rise in a thermal process—such as hardening, annealing, or drying. It is a central component of process control in industrial heat treatment and is precisely controlled by process controllers. In combination with a process control system such as Prosys from Demig, heating curves can be precisely planned, documented, and reproduced.
The Importance of the Heating Curve in Heat Treatment
Strict adherence to the heating curve is crucial for the quality and reproducibility of heat-treated components. It defines not only the heating rate but also holding zones, plateaus, and transitions between process phases such as holding, cooling, or tempering.
Typical characteristics of a heating curve:
- Temperature rise over a defined time (e.g., 5 K/min)
- Hold times at critical transformation temperatures
- Segmentation into multiple control ranges with transitions
Even the slightest deviations—such as heating too quickly—can cause microstructural changes, stresses, or warping. Therefore, heating curves must be precisely controlled and continuously monitored.
Control via process controllers and control systems
Demig process controllers enable multi-stage control of complex heating curves with high accuracy and fast response times. Freely definable programs allow temperature profiles to be precisely tailored to the material, component geometry, and furnace type.
The Prosys process control system handles key tasks in this process:
- Management and selection of predefined heating curves
- Real-time visualization of the temperature profile
- Batch-based archiving for traceability
The close integration of the controller and the control system also allows heating curves to be adjusted to process data in real time—for example, to compensate for disturbances or to optimize energy efficiency.
Practical benefits and quality advantages
The digital management and comprehensive documentation of heating curves offer numerous advantages for companies. They enable significantly greater process stability, as procedures can be reliably reproduced. At the same time, scrap is reduced and warpage is minimized—especially for sensitive or geometrically complex components. It also meets traceability requirements and compliance obligations: Automatic logging simplifies audits and saves time on documentation. With Demig’s technology, heating processes can not only be precisely controlled but also intelligently monitored and continuously optimized—a key building block on the path to connected, data-driven manufacturing in line with Industry 4.0.
Conclusion
The heating profile is the foundation of every quality-assured heat treatment. Through the use of highly advanced process controllers and the Prosys process control system, Demig ensures that temperature profiles are precisely maintained, intelligently adjusted, and fully documented—for the highest component quality, process reliability, and digital traceability.