Aplicaciones
Heat treatment: the key technology for superior performance
Heat treatment furnaces are crucially important industrial plants, used in a wide range of sectors, from the most demanding (such as automotive and aerospace) to the most common applications in precision mechanics and tool production.
These plants play a crucial role in the transformation of metallic materials. Through controlled heating and cooling cycles, the metal’s internal structure is modified so that it acquires the mechanical and physical properties needed to guarantee high performance, reliability and durability.
Necesidades:
Temperature control in the thermal process
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Digital recording of process variables
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Furnace high temperature limit switch
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Electrical heating loads control
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Thermal process temperature measurement
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Necesidad:
Temperature control in the thermal process
Temperature is the most critical variable in the metal heat treatment process. Precise and repeatable control is essential to ensure consistent, high-quality production. This is particularly important in the aerospace and aeronautical sectors, where accuracy must comply with regulations such as AMS2750 and CQI-9. In batch furnaces, the temperature control system must generate a dedicated thermal profile, with several heating and cooling phases, each with specific parameters. It is only an accurate temperature control that makes it possible to comply with the metallurgical specifications and ensure the conformity of the final product.
Solución:
The 1850 controller is the ideal solution for the precise and reliable control of furnace temperature. With its highly efficient control algorithm, the controller ensures compliance with the thermal specifications required by the treated materials.
Certified to be compliant with AMS2750 (aerospace industry) and CQI-9 (automotive industry), the 1850 controller is suitable for applications of these kinds, which require a high level of precision in thermal control.
Key features:
- Generation of set-point profiles;
- Control outputs for SSRs and motorised valves;
- Colour LCD interface;
- Multilingual diagnostic messages;
- Logic and mathematical operations.
Necesidad:
Digital recording of process variables
The recording of temperatures during heat treatments is essential to ensure the quality and safety of the treated materials. Accurate monitoring and documenting the thermal parameters ensure that the treatment cycle meets the required specifications, preventing defects and variations in the final product. Furthermore, these records are a fundamental requirement to comply with regulations and industry standards, such as AMS2750 and CQI-9, which are particularly strict in the aerospace and automotive sectors. This process also ensures the traceability of every production batch, guaranteeing the total reliability of the production process.
Solución:
For data recording, Gefran offers the 3850T multifunction controller, a device that integrates several functions, including efficient data logging compliant with the ASM2750 and CQI-9 specifications. This function, associated with the Real Time Clock, can store process data, digital Input/Output signals and alarm statuses.
Key features:
- Graphical touch screen interface;
- Storage in open or encrypted format;
- Export of files locally or via Ethernet network;
- Export of data in .CSV or .PDF format.
Necesidad:
Furnace high temperature limit switch
To protect the system and ensure the safety of operators in the event of furnace overheating, it is necessary to adopt suitable safety devices, known as safety limit switch. Excess heat can compromise the integrity of the furnace, damaging resistors, sensors and refractory insulation, with the risk of fire, explosion or mechanical failure. In the event of malfunction of the primary system and exceeding the threshold, the safety system automatically operating by activating alarms and shutting down the plant, preventing damage and protecting operators. In the US market, the Factory Mutual (FM) regulation requires devices to be certified, to guarantee correct operation if the allowed temperature is exceeded.
Solución:
The 650L (48×48 format) and 1250L (48×96) safety indicators, with Factory Mutual (FM) certification, are devices designed to detect overtemperatures in industrial heating processes and activate a signal that move the system in safety mode. For easier installation and use, they are supplied with a ready-to-use configuration, inclusive of the function of retentive alarm memory, with operator acknowledgement action required. Acknowledgement procedures include pressing a dedicated front key (red R), digital input (optional) or serial line (optional). The LCD display screen shows clear messages that guide the operator in identifying the system’s status, making interventions simple and immediate.
Necesidad:
Electrical heating loads control
In industrial electric heating, power management is crucial to ensure temperature uniformity, energy efficiency and operational continuity. Heating applications require systems that can adapt to different types of loads – from linear resistors to transformers – maintaining stability even if process variations occur.
Meeting these needs requires solutions with configuration flexibility, advanced diagnostics for predictive maintenance and compatibility with the latest communication protocols. Effective I/O integration enables signal management, from command retransmission to the monitoring of process variables.
Finally, the need for installations in small spaces makes it essential to have compact and robust systems that can guarantee safety, efficiency and reduction of system downtime.
In electrical heating, to ensure treatment temperatures above 1000°C, Power Controllers are used, as these smart devices manage electrical heaters power precisely and efficiently.
The key features of the GPC series are:
- Current ratings from 40 to 600 A;
- Single, two- and three-phase configurations;
- Configurable control modes;
- Integrated diagnostics;
- Fieldbus connectivity.
Necesidad:
Thermal process temperature measurement
Temperature is the most critical variable in heat treatment processes. Accurate control is crucial to guarantee the required mechanical properties, process repeatability, compliance with quality standards and operational safety. The temperature probe must operate in high temperature environments, ensuring a stable and continuous measurement. An essential element is the sheath, which protects the sensitive element, usually a thermocouple: in addition to being resistant to high temperatures, it must withstand the action of process gases in the furnace, which are present in processes such as nitriding. This is why choosing a suitable coating material is necessary, in order to guarantee reliability and durability.
The temperature probes of the TC8 series, equipped with a thermocouple sensitive element, are an ideal solution for heat treatment applications with temperatures that reach 1000°C. The possibility of choosing the type of thermocouple, the measuring range, the installation length and the material of the sheath are why these devices have such high versatility of use. For example, an AISI 316 steel sheath is suitable for medium temperatures in non-aggressive atmospheres, while the INCONEL 600 nickel-chromium-iron base metal alloy, which is resistant to reactive gases, is more suitable for high temperatures in aggressive environments
Operating principle
When it comes to heat treatments, batch furnaces are the most popular and appreciated solution because of their extraordinary versatility. The front opening design facilitates the loading of single components or complex batches, including items with uneven shapes or delicate materials, making the process simple and safe.
Designed for industrial applications, these devices are equipped with a closed thermal chamber with internal lining made of refractory materials, which guarantees excellent insulation and uniformity of treatment throughout the load.
With temperatures that can reach 1000°C, batch furnaces are ideal for a wide range of heat treatments, including quenching, tempering, annealing and normalising. Each process is managed according to a dedicated thermal profile, which is essential to obtain the desired metallurgical properties.
Reliable, flexible and efficient, batch furnaces are the perfect choice if you are looking for high performance and consistent results.
Requirements and Technology
In heat treatments, temperature is the most critical parameter, it must be managed with absolute precision and guaranteeing constant stability, to ensure reliable results and conformity with the highest standards.
To achieve this, modern systems rely on advanced PID controllers, which are equipped with optimised algorithms and auto-tuning functions that simplify management and ensure intuitive and efficient control of the entire process. Heat can be produced through electrical resistors or gas combustion: in the first case, the temperature controller communicates with electronic Power Controllers, which modulate the resistance thermal energy with extreme precision; in the second case, the controller manages the gas valves directly, guaranteeing reactivity and safety.
But controlling is not enough: it is also crucial to record the temperature profile, especially in highly specialised sectors such as aerospace and aeronautics, where process traceability is essential to certify quality and comply with the strictest regulations.
Finally, to protect the system and ensure the safety of operators, it is essential to integrate dedicated protection devices, such as safety thresholds against overtemperatures, which intervene promptly to avoid critical situations.
