Over the decades, the manufacturing industry has learnt how to process metals and alloys in order to obtain products which meet different needs. Working on properties such as strength, elasticity, ductility and hardness, through heat treatment, has in fact favoured technological improvement and the spread of metals and metal alloys in many sectors.
Let us first define what the heat treatment process of metals is, guided by the experience and solutions proposed by CD Automation for this application.
Introduction to heat treatment
Heat treatment can be defined as a combination of heating and cooling operations to which a metal or alloy in a solid state is subjected in order to obtain the desired conditions and properties. Simplifying as much as possible, a classic heat treatment consists of a temperature raising or heating phase, a temperature holding or holding phase and a cooling down to ambient or cryogenic temperatures.
What are the goals?
Heat treatments can be used to homogenise cast metal alloys, to improve their hot workability, to soften metals before and during hot and cold working operations, or to alter their microstructure in order to achieve the desired mechanical properties.
Heat treatments of metal alloys are also used to modify the surface chemical structure of materials. This modification is generated through the diffusion of carbon, nitrogen and other gaseous or solid materials onto the surface of the component. These processes are used to give a certain surface hardness and to increase wear, corrosion and stress resistance.
The parameters involved
In order to choose the most appropriate heat treatment process and to make operations more efficient, several parameters should be taken into account, including:
- Type of alloy;
- Heating and cooling requirements;
- Work input;
- Time;
- Atmosphere;
- Surface plating;
- Surface diffusion.
In order for metal components to be suitable for their intended purpose, it may be necessary to subject them to a series of conditioning and finishing treatments, performed to ensure that the combination required by these parameters is precisely controlled in order to obtain the desired component.
Treatments are performed in furnaces where gases are used to control the process atmosphere. Controlled atmospheres are used to reduce the effects of oxidation or to provide an enriched atmosphere for surface chemical effects on the component undergoing the operation.
Heat-treatment methods
According to their purpose, heat treatment operations are subdivided into:
- General treatments. These include: homogenisation → performed prior to hot working processes with the aim of equalising the temperature of an alloy or reducing the micro-segregation effect due to non-uniform chemical composition.
Annealing → includes various heat treatment processes aimed at softening alloys and increasing their ductility prior to cold working.
Normalisation/ distension → performed in order to eliminate internal stresses in welded, cast or rapidly cooled components.
- Treatments which change the phase structure of an alloy. These include hardening → this is achieved by heating an alloy to a predefined temperature and then tempering it in oil, water, air or using a special polymer quench.
Tempering → generally follows the hardening process in order to remove much of the acquired brittleness from the alloy, while retaining the hardness of the components.
Induction hardening → rapid heating with an induction coil is immediately followed by a hardening process to harden the metal alloy. Alternatively, this same process can be performed by direct contact with an incandescent flame or by laser heating techniques.
- Treatments which change the surface chemical structure of an alloy. In carburizing, nitriding, carbonitriding and nitrocarburizing processes, the surface layers of the alloy are hardened and tempered by exposing the component to a carbon or nitrogen enriched gaseous atmosphere, while the material is subjected to a high heat profile prior to tempering.
- Other specialised processes include hot isostatic pressure (HIP ping) → used for the densification of castings and pre-synthesised components and in diffusion welding of alloys. It requires extremely high temperatures and pressures in a specially designed vessel.
Sintering → Many products with complex cross-sectional shapes are obtained from powdered base materials pressed or moulded into the shape of the component. Sintering takes place in a controlled atmosphere environment and is used to strengthen the bond of compacted powder components in a process cycle with set times and temperatures.
Why use CD Automation’s know-how?
As can be deduced from this overview, the different types of heat treatment require advanced knowledge in the fields of thermotechnics and materials science. For this reason, and in order to make metal heat treatment processes efficient and sustainable, it is essential to turn to reliable partners with decades of know-how. This is the case with CD Automation, a company that for over thirty years has been producing intelligent systems for controlling electrical power via static contactors and industrial temperature controllers for metal and glass heat treatment furnaces and for: plastics machinery, packaging, the food industry, Oil & Gas and systems for managing renewable and traditional energies.
Different solutions for multiple benefits
More specifically, the company manufactures thyristor power units and soft starters of the highest quality, with the support of an international system of subsidiaries and partners of primary importance in the industrial thermoregulation sector. Through these products, the company guarantees the reduction of:
- Disturbances on the power supply line,
- Heating of electrical cables,
- Energy losses.
The control system designed by CD Automation makes it possible to maintain Power Factor values close to 1 and avoid energy cost penalties. Last but not least, the company is committed to reducing the size of the control panel by integrating several functions in a single multi-channel unit, thus meeting the requirements of compactness, competitiveness and sustainability of processes and products.
Introducing the REVO C 3PH unit
Specifically for metal heat treatment processes, CD Automation has produced the REVO C 3PH universal power controller: a high-performance unit, adaptable to all SCR applications, including inductive loads, high-temperature furnace resistors, infrared or UV furnaces.
REVO C 3PH is equipped with an advanced microprocessor that makes it universal and fully configurable via software. The unit also proves to be an indispensable tool in Industry 4.0, thanks to its Ethernet IP and integrated Profinet communication, with libraries to reduce integration time.
Technical features
REVO C is the most complete unit ever because of its three-phase synchronisation, phase angle switching, measurement accuracy and current limit. In fact, the three-phase power controller has:
- Universal inputs: Analogue 4:20mA / 0:10V and SSR input configurable via software.
- Current range from 30 to 2100A.
- Voltage ranges 480V, 600V and 690V +/-10%.
- OLED Display, providing optimal operator vision and user-friendly messages.
- Powerful diagnostics, with clear messages in the event of an alarm.
- All firing types come standard: Zero Cross, Half Cycle, Single Cycle, Burst Firing, Delayed Triggering, Phase Angle and Soft Start.
- Universal Control Mode/strong>: can be configured with feedback on Current, Voltage, Power or in Open Loop mode.
- Data logging Integrated on SD memory card with programmable storage intervals
- High-precision measurement (True RMS Value per V, I e VxI) =< 1%
- Integrated fuses with quick and easy access allow for reduced cabinet space and more efficient heat dissipation.
- High short circuit protection: 100 KA Short Circuit Current rating (SCCR) up to 600V. Oversizing of Thyristors and parts subjected to temperature with the use of high efficiency heat exchangers.
- USB port on the front of the unit allows the REVO C to be configured easily and safely as the unit is powered by the USB port itself.
- Integrated signal analyser for faster and easier identification of process problems.
Would you like to find out how to make your metal heat treatment processes more efficient and competitive? Contact us us and book a free consultation session with one of our experts. You will receive strategic proposals customised to your needs.
