For aviation (typically, Nadcap and AMS2750 US military standards) and automotive (TS16949 test device) customers, process consistency is the main issue. Compatibility with higher acceptable standards is building confidence between heat treatment equipment manufacturers and customers . This is especially true when the heat treatment furnace design matches the design of the expert process control system. Eurotherm already has a unique knowledge of aviation and automotive heat treatment specifications. This knowledge and specially designed products and systems help ensure that the controlled parameters are kept within acceptable limits at all times.
Modern control system design mainly considers three issues:
① The gain and thermal hysteresis of most modern heat treatment furnaces with low-calorie material isolation are becoming the main factors of load size and set point, rather than heat treatment furnace structure or its own parts.
② Special consideration is given to the temperature of the actual workload. Customers are looking for them in their control algorithms. Therefore, more heat treatments use specific workload temperature optimization methods.
③ Acceptable heat treatments are generally approved by heat treatment furnaces defined by specific classifications. In order to obtain the maximum efficiency of production planning and the maximum value of workload capacity, it is critical that heat treatment equipment has been working at the most appropriate level.
The customer’s recurring problems are excessive work load temperature drift, which occurs when starting or trajectory slope, even when the controlled area is very close to the required thermal trajectory. Because many workpieces have different cross-sectional areas, annoying temperature drift can lead to destructive consequences, especially in thin-section parts under load. These drifts can cause failure audits of heat treatment furnaces. Because of this, many users turn to the rather crude method of excessive elimination and gain optimization, which is added to the heat treatment cycle time.