The Role of Heat Treatment Power Consoles in Welding

In metal fabrication and construction, welding is a pivotal process that ensures the robustness and durability of metal structures. It's more than just joining metals; it's about ensuring the joint can withstand stress and last long. This is where the role of heat treatment becomes indispensable. Heat treatment power consoles are paramount among the various tools used for this purpose.

What is a Heat Treatment Power Console?

Like those in the provided image, heat treatment power consoles are devices designed to control heat application to metals during post-weld heat treatment (PWHT). They come with a range of switches, dials, and connectors that allow operators to set specific temperatures, monitor heat levels, and control the duration of the treatment.

Why is Heat Treatment Necessary?

After welding, metals often undergo structural changes at their molecular level. These changes can lead to internal stresses, reduced ductility, and increased brittleness. Heat treatment, therefore, becomes essential to:

• Relieve internal stresses.
• Improve mechanical properties like tensile strength and ductility.
• Reduce the risk of corrosion.
• Enhance the overall lifespan of the weld.

The Significance of Power Consoles

1. Precision Control: With a power console, operators can precisely control the temperature to which the metal is exposed, ensuring that the metal undergoes optimal heat treatment, neither too much nor too little.
2. Uniform Heating: These consoles provide consistent and uniform heating across the welded area, which is crucial as uneven heating can lead to new stresses or distortions.
3. Safety: High-quality consoles come with safety features like overheat protection and alarms, ensuring the safety of the equipment and the operator.
4. Documentation & Monitoring: Modern power consoles may offer features like data logging, allowing operators to monitor the heat treatment process closely and maintain records for quality assurance.

Impact on Metal Fabrication & Construction

In industries like metal fabrication and construction, where the integrity of welds is critical, heat treatment power consoles play a defining role.

• They ensure that large structures like bridges, skyscrapers, and pipelines remain durable and safe.
• In the automotive and aerospace industries, where the precision of welds is crucial, these consoles guarantee that parts can withstand intense pressures and stresses.

Conclusion

Welding, though a fundamental process, comes with its set of challenges. The post-weld molecular changes in metals can compromise the quality of the weld. However, these challenges are effectively addressed with tools like heat treatment power consoles. By ensuring the robustness of welds, these consoles contribute significantly to the longevity and safety of metal structures in various industries. The next time you witness a magnificent metal structure, remember the unsung hero behind it - the heat treatment power console.

Hotfoil-EHS
https://hotfoilehs.com


609-588-0900

Hotfoil-EHS Power Consoles: Eurotherm Master Controller Set-up for PWHT Procedure

This video explains how to set up the Eurotherm Temperature Controller on a Hotfoil-EHS Power Console in a Primary/Secondary relationship.

Understanding heating rate, soaking temperature, soaking time and cooling rate for PWHT (Post Weld Heat Treatment)

Post-weld heat treatment (PWHT) is a crucial step in the welding process, as it helps to mitigate the adverse effects of welding on the microstructure and mechanical properties of the welded components. The main objectives of PWHT are to reduce residual stresses, improve ductility, reduce the risk of stress corrosion cracking, and temper or soften the heat-affected zone (HAZ). The four key factors that influence the effectiveness of PWHT are heating rate, soaking temperature, soaking time, and cooling rate.

1. Heating rate: The heating rate refers to the rate at which the temperature of the welded component increases to reach the desired soaking temperature. A controlled and uniform heating rate is essential to avoid the formation of undesirable temperature gradients within the material, which can lead to distortion and cracking. A slow, steady heating rate also ensures that the material undergoes sufficient thermal stress relief, reducing residual stresses and improving the mechanical properties.
2. Soaking temperature: The soaking temperature is the target temperature at which the material stays during the heat treatment. The selection of an appropriate soaking temperature is vital, as it determines the extent of stress relief, the softening of the HAZ, and the overall improvement of mechanical properties. The soaking temperature is carefully chosen based on the material's composition, prior heat treatment, and the desired outcomes of the PWHT. Too high a temperature may cause grain coarsening and reduce the material's strength, while too low a temperature may not provide adequate stress relief or soften.
3. Soaking time refers to the duration the material holds at the soaking temperature. The soaking time is critical for allowing sufficient time for the microstructural changes to occur, such as diffusion of hydrogen, precipitation of carbides, or tempering of martensite. Proper soaking time reduces residual stresses and improves ductility and the desired microstructural changes. Insufficient soaking time can lead to incomplete stress relief, while excessive soaking time may result in grain coarsening, which can adversely affect the material's mechanical properties.
4. Cooling rate: The cooling rate is the rate at which the temperature of the material reduces after the completion of the soaking phase. The cooling rate significantly influences the material's final microstructure and mechanical properties. Controlled and uniform cooling is essential to prevent thermal gradients that could cause distortion or cracking. Different cooling rates may be required depending on the material and the desired outcome. Faster cooling may achieve a harder, more robust microstructure, while slower cooling rates can produce a more ductile, softer material.

In summary, the heating rate, soaking temperature, soaking time, and cooling rate are essential parameters requiring careful controlling during post-weld heat treatment. These factors determine the effectiveness of the heat treatment process in reducing residual stresses, improving ductility, reducing the risk of stress corrosion cracking, and achieving the desired microstructure and mechanical properties in the welded components.

Welding Pre and Post Heat Treatment Power Consoles

Power consoles, also known as control consoles or heat treatment controllers, play a critical role in the heat treatment process by controlling and monitoring the temperature and other parameters of the heating equipment. They typically include a temperature controller, over-temperature protection, and a programmable controller to ensure that the heat treatment process meets the specified parameters, such as temperature and time. They also provide data logging and communication capabilities for process monitoring and control.

Heat treatment power consoles provide control over multiple zones. The number of zones a power console can control can vary depending on the design and capabilities of the specific power console. Some heat treatment power consoles may be able to manage one zone, while others may handle multiple zones. It is common to have four temperature zones under control for industrial heat treatment, but power consoles may even control up to 24 zones. These zones are typically used to control different workpiece sections and can be used to create specific temperature profiles for other parts of the process.

Power consoles in heat treatment typically control various heating systems, such as electric resistance, gas-fired, or induction heating. Electric resistance heating systems use electric heating elements, such as resistance wire, to heat the workpiece. Gas-fired heating systems use a combustion process to generate heat in the furnace. Induction heating systems use an electromagnetic field to generate heat within the target. The power console controls the current flow to the induction coils to develop the electromagnetic field and maintain the desired temperature within the target. In some cases, power consoles also contain cooling systems and atmosphere generators to achieve specific temperature profiles and atmospheres during heat treatment.

https://hotfoilehs.com​

609.588.0900

24 Zone Custom Heat Treating Power Console

https://hotfoilehs.com​

609.588.0900

Hotfoil-EHS Heat Treating Power Consoles

Precise control over your pre-weld and post-weld heat treatment parameters are critical. Accurate temperature control, specific soak times, uniformity, and controlled heat up and cool down times are required to ensure strong welds. Hotfoil-EHS power consoles are designed to provide the best control, easiest user interface, and longest lasting operation, even in the toughest environments. Using only the highest quality components, Hotfoil-EHS power consoles are field-tested and application proven. Control systems can be specified with or without recorders or ramping controllers, and are standardly available in 6, 9, 12, 18, and 24 zone configurations.

https://hotfoilehs.com
609-588-0900

Hotfoil-EHS Manufacturing and Distribution Facilities

Hotfoil-EHS, Inc. is an organization with over 70 employees and an impressive engineering capability. Through continued re-investment of profits, Hotfoil-EHS acquired additional large fabrication facilities and today is a full-service engineering, design, and manufacturing company of industrial heating equipment. Their Hamilton, NJ headquarters provides 68,000-square-feet of manufacturing space, with other manufacturing and distribution facilities located in Chattanooga, TN, LaPorte, TX, and Birmingham, England.

https://hotfoilehs.com

609-588-0900

American Made Heat Treatment Equipment: Everything You Need from One Reliable and Knowledgeable Source

Hotfoil-EHS manufactures pre and post-weld heat treating equipment including: power consoles; ceramic mat heaters; thermocouple attachment units (TAUs); pin welders; Brinell testers; Poldi hardness testers; thermocouple wire; insulation; and accessories.

EHS engineers, designs, and manufactures proven systems to effectively complete any project more efficiently than competitive systems, while staying competitive within any budget. Years of application experience and successful installation history have produced thousands of happy customers.  Quality and durability at an affordable price, and a focus on customer service second to none.

Welding Heat Treatment Products from Hotfoil-EHS

Here's a little shameless, self-promotion from your friends at Hotfoil-EHS.

Process Heating: Induction

Induction heating coils around large pipe
in preparation of welding.

The principles of induction heating have been applied to manufacturing operations since the 1930s, when the first channel-type induction furnaces were introduced for metals melting operations. Soon afterward, coreless induction furnaces were developed for melting, superheating, and holding. In the 1940s, the technology was also used to harden metal engine parts. More recently, an emphasis on improved quality control has led to increased use of induction technology in the ferrous and nonferrous metals industries.

In a basic induction heating setup, a solid state power supply sends an alternating current (AC) through a copper coil, and the part to be heated is placed inside the coil. When a metal part is placed within the coil and enters the magnetic eld, circulating eddy currents are induced within the part. These currents ow against the electrical resistivity of the metal, generating precise and localized heat without any direct contact between the part and the coil. 

An induction furnace induces an electric current in the material to be melted, creating eddy currents which dissipate energy and produce heat. The current is induced by surrounding the material with a wire coil carrying an electric current. When the material begins to melt, electromagnetic forces agitate and mix it. Mixing and melting rates can be controlled by varying the frequency and power of the current in the wire coil. Coreless furnaces have a refractory crucible surrounded by a water-cooled AC current coil. Coreless induction furnaces are used primarily for remelting in foundry operations and for vacuum refining of specialty metals.

Induction heating power console (Hotfoil-EHS)

Channel furnaces have a primary coil wound on a core. The secondary side of the core is in the furnace interior, surrounded by a molten metal loop. Channel furnaces are usually holding furnaces for nonferrous metals melting, combined with a fuel- red cupola, arc, or coreless induction furnace, although they are also used for melting as well.

The efficiency of an induction heating system for a specific application depends on several factors: the characteristics of the part itself, the design of the induction coil, the capacity of the power supply, and the degree of temperature change required for the application.

Induction heating works directly with conductive materials only, typically metals. Plastics and other nonconductive materials often can be heated indirectly by first heating a conductive metal medium that transfers heat to the nonconductive material.

With conductive materials, about 80% of the heating effect occurs on the surface or “skin” of the part. The heating intensity diminishes as the distance from the surface increases, so small or thin parts generally heat more quickly than large thick parts, especially if the larger parts need to be heated all the way through.

Induction heating can also be used to heat liquids in vessels and pipelines, primarily in the petrochemical industry. Induction heating involves no contact between the material being heating and the heat source, which is important for some operations. This lack of contact facilitates automation of the manufacturing processes. Other examples include heat treating, curing of coatings, and drying.

Induction heating often is used where repetitive operations are performed. Once an induction system is calibrated for a part, work pieces can be loaded and unloaded automatically. Induction systems are often used in applications where only a small selected part of a work piece needs to be heated. Because induction systems are clean and release no emissions, sometimes a part can be hardened on an assembly line without having to go to a remote heat treating operation.

Hotfoil-EHS Products

All Stainless Heat Treat Power Consoles

Hotfoil-EHS Stainless Steel Power Consoles

Power consoles are standardly offered in 6, 9, 12, 18, and 24 zone configurations with a variety of control and recording systems. All Hotfoil-EHS Power Consoles are available in Stainless Steel and can be customize to your requirements.

With decades of experience in challenging applications, and thousands of successful installations, Hotfoil-EHS maintains their well deserved reputation as the highest quality and most competitively priced manufacturer of heat treat power consoles in the world.

Custom Heat Treating Power Consoles Solve Many Potential Field Problems

Weather-proof, Stainless Steel
Power Console

Standard heat treating power consoles available from a variety of manufacturers pretty much cover the same set of basic welding requirements. In many field situations however, there can be unusual circumstances such as difficult locations, available power sources, and environmental concerns. In these situations custom manufactured power consoles will provide welding outcomes with fewer operational problems, higher quality output, and greater safety.

Standard power consoles are available 3, 6, 9, 12, 18, 24 and 36 zone configuration (zones are many times referred to as "way" such as 3 way console, 6 way console, 9 way console, etc.) Each zone provides a point of control. The type of control can vary depending on the requirement of the weld. Some zones only need simple on-off or proportional control. Some welding jobs require more sophisticated temperature control profiles, thus requiring tight control with temperature vs. time ramping. Additionally, these more sophisticated control requirements may also need data logging or recording for quality compliance. In many situations custom cable sets are required to deliver the heater power and thermocouples to the workpiece. A power console manufacturer should have the experience and knowledge to consult, recommend, and install whatever zone control and cabling requirements your job needs.

Power console and
custom cable sets

The operating environment is another important consideration for power console customization. Standard power console cabinets are usually made from a medium gage sheet metal and painted with an industrial grade rust-resistant paint. While fine for relatively dry and non-corrosive atmospheres, these are subject to quick deterioration when moved into areas where higher than normal concentrations of salt, chlorine, or other corrosive gasses exist. In these situations, careful consideration of exposed materials needs to be applied. Perhaps an all stainless steel design is needed? Or maybe special corrosion resistant paints or epoxy resins should be specified? Or maybe you only need a special color paint? Working with a power console manufacturer who has the flexibility in their manufacturing process and experience on the floor to provide these options is preferred.

Custom painted
power console

Finally, look for a power console manufacturer who can handle unusual power system requirements. A manufacturer who can adapt their systems to unique voltages and current requirements is a big plus. Look for an equipment company that has experience and production capabilities for a wide variety of transformers - single or dual- and can even supply custom built transformers.

And of course, always try and find equipment built right here in the USA.

For more information on ANY welding power console, contact:

Hotfoil-EHS
2960 East State Street Ext.
Hamilton, NJ 08619
Phone # 609.588.0900
Fax # 609.588.8333

www.hotfoilehs.com
Email: dap@hotfoilehs.com

Automatic Heat Treatment Power Consoles

Typical Power Console
(courtesy of HotfoilEHS)

Automatic heat treatment power consoles are used to control various heat treatment processes (i.e. pre-weld, post-weld) by closely controlling the temperature of the item being welded. The power console accurately controls the ramping rate (up and down), the soak temperature, the set point and the time. Power consoles are available from 2 to 24 zones of control. Zone can be used either in the fully automatic or manual mode.

Ceramic Mat Heater

The power console is used to provide power to electric heating elements called ceramic mat heaters. Ceramic mat heaters are constructed of nichrome wire interwoven into ceramic beads which provides electrical insulation and protection. These heaters are quite rugged and conform to curved and irregular shapes.

Thermocouples are used to sense the target temperature and send their signal back to some type of electronic temperature controller, recorder, or combination thereof. The sophistication of the control system can range from simple manual control to fully automatic control with large graphic displays. Recorders are frequently used to document the pre-heat, soak, and post-heat process. Welding integrity depends on precise and accurate control.

Recorder used on
welding power console.

Heat treatment power consoles are built on sturdy chassis of steel and depending on ambient conditions, stainless steel. Construction includes wheels and handles for easy relocation and many electrical components for safety and convenience (such as amp meters, indicator lights, cut-off switches, fuses, and alarms).

For more information, contact:

Hotfoil-EHS, Inc.
2960 East State Street Ext.
Hamilton, NJ 08619
Phone # 609.588.0900
Fax # 609.588.8333
www.hotfoilehs.com
Email: dap@hotfoilehs.com