One Minute Mentor: Horizontal Retort Furnace

Gas nitriding and nitrocarburizing processes can be processed with fixed gasifying amounts of ammonia, nitrogen, and, for nitrocarburizing, a carburizing and oxidizing agent. However, this does not produce consistent results if different load surfaces are treated with the same fixed gasifying amounts. Furthermore, especially for nitriding processes, the ammonia gasifying has to be reduced or diluted with nitrogen after several hours because the nitrogen uptake of a load decreases. Another quite popular method, usually called the “Floe process,” is a two-step nitriding, where two different nitriding temperatures and different gas flows allow adjustment of the nitriding potential (KN) to the requirements.

Therefore, modern gas nitriding and nitrocarburizing furnaces are equipped with sensor systems and a process control unit that allow the measurement and automatic control of the nitriding potential (KN). The figure shows a schematic of a typical horizontal retort furnace. Similar to the vertical execution, a good circulation of the process gas is needed to get uniform results, which can be reached by the use of a muffle and a high circulation rate. Indirect cooling is performed with an external cooling fan, blowing cold air along the retort. 

For more information, click on the link below (subscription required). Then scroll to Figure 24

R Schneider; R. Mesquita; H. Altena; T. Müller; P. Seemann, Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

Solar Atmospheres of California adds Airbus approval

Solar Atmospheres, Fontana, Calif., has announced that they are now Airbus approved for heat treating.

Frank Trujillo, director of Sales for Solar Atmospheres of California, stated that, “Many Airbus suppliers were in need of a heat treater in the West that could process parts, plates and bars in support of increased Airbus production rates. SCA is proud to be a partner on the Airbus Team!”

With our wide range of furnaces, we are capable of processing very small pieces or loads of 50,000 pounds and up to 24 feet in length. This approval will translate into improved lead-times and greater efficiencies for all Airbus suppliers that require heat treat services in the Western Region.

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Quintus Technologies supplies high pressure Flexform press to airframe manufacturer

Quintus Technologies, Vasteras, Sweden, announced that they will supply a high pressure fluid cell press to France’s LAUAK Group, a Tier 1 supplier to the aerospace industry. The press will be installed at the LAUAK Aerostructures factory in Grandola, Portugal, in September 2023. 

Reaffirming its continued commitment to productivity enhancement, LAUAK selected the Quintus model QFC 0.7×1.8-800 press with high pressure technology to bolster its manufacturing efficiency. “The forming press is undoubtedly at the heart of sheet metal production,” says Mikel Charritton, LAUAK Group Managing Director. “Especially in the context of the current aerospace ramp-up, in particular the A320, A350, and B737 programs, LAUAK’s capital equipment investments are strongly influenced by the imperatives of competitiveness. This press significantly increases and secures our production capacity.” Quintus’s proprietary hydroforming process requires only one rigid tool half, an innovation that not only generates significant tool cost savings but also eliminates several forming operations, intermediate heat treatments, and operator dependencies. 

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One Minute Mentor: Gas nitriding equipment

Gas nitriding and nitrocarburizing can be processed in horizontal or vertical chamber furnaces with refractory insulation. However, to allow a quick change of the atmosphere and to avoid influences resulting from previous processes in the same furnace, retort furnaces are preferred.

To enable an acceptable production capacity, large vertical retort furnaces are used. The figure is a schematic sketch of a vertical retort furnace with a compensator for sealing against the atmosphere. Nowadays large horizontal retort furnaces are also used. Horizontal retort furnaces of different size and execution are preferred for nitrocarburizing processes. Similar to the vertical execution, a good circulation of the process gas is needed to get uniform results, which can be reached by the use of a muffle and a high circulation rate. Indirect cooling is performed with an external cooling fan, blowing cold air along the retort. Other designs allow direct cooling of the process gas with an external heat exchanger.

For more information, click on the link below (subscription required). Then scroll to Figure 23

R Schneider; R. Mesquita; H. Altena; T. Müller; P. Seemann, Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

Lindberg/MPH ships mesh belt conveyor furnace for use with powdered metal

Lindberg/MPH, Mich., has announced the shipment of an electrically heated, full muffle, mesh belt conveyor furnace. This furnace is designed for treating pressed powdered material.

The furnace is designed for applications with a maximum process temperature of 1000° C (1832° F) that utilize a nitrogen or clean dry filtered air process atmosphere. The unit is configured with 9 temperature control zones and includes a water-cooling section. The conveyor system features a 14 inch wide mesh belt with belt stop alarm to provide an audible and visual indication in case of a conveyor stoppage.

There are purge chambers at the entrance and exit of this conveyor furnace. In these chambers purge gas flows from perforated plenum chambers above and below the belt and exhaust stacks with adjustable butterfly valves are located at the inner ends of each chamber. Load and unload tables at the entrance and exit of the conveyor provide ease of product transfer for the operator.

The furnace zone temperatures are controlled by Eurotherm controllers. These controllers have advanced PID control with variable overshoot inhibition. A hi-limit Eurotherm controller guards against over temperature conditions in each zone of temperature control.  A visual and audible alert and removal of power to the heating element occur in the event the monitor temperature exceeds a desired set point. 

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Seco/Warwick to supply a vacuum furnace specifically designed for the MRO industry

Seco/Warwick, Meadville, Pa., will supply a vacuum furnace specifically for the maintenance, repair, and operations (MRO) industry. The solution will be utilized for repair solutions for both complex aircraft engines and gas turbines for the energy industry in Hungary.

The furnace on order is a unique solution due to the effective size of the heating chamber. It has been adapted to the AeroSpace Power requirements and has a working area of 1300 x 1000 x 1500 mm. Thanks to this, the furnace can accommodate large components – mainly aircraft parts, as well as gas turbines for the energy sector.

The featured technology on order, in addition to non-standard dimensions, is designed to process work in the presence of two gases: argon (used for partial pressure) and nitrogen, which is used mainly in the cooling process.

Additionally, the furnace will be equipped with a dew point sensor for each of the gases. It is a system which solves one of heat treatment’s very critical operational requirements, which is to control the quality/purity of gas used during the process. Vector also features a partial pressure control system based on three gases (hydrogen, argon, and nitrogen) to help prevent evaporation and sublimation of alloying elements from the load surface during the vacuum heat treatment or vacuum brazing process.

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One Minute Mentor: Vacuum Furnaces

The demands on vacuum-hardening technology have changed in recent decades. One of the most important considerations that must be met is the accomplishment of highest dimensional stability with optimal microstructural properties and minimal change of the surface of the workpieces. 

Minimizing exposure to air during the heat treatment by reducing the quantity of oxygen in a heat treatment furnace, as with creating a vacuum, is an excellent method for preventing changes in surface appearance and chemical composition.

Suppliers of modern vacuum furnaces are further faced with new demands, such as increasing quenching speed to improve microstructural and mechanical properties by reducing grain size, and enhancing hardness and toughness and/or reducing distortion due to the hardening process. Furthermore, quality standards such as AMS 2750d or North American Die Casting Association (NADCA), which describe temperature homogeneity or quenching speeds and resulting and needed workpiece properties, had a significant effect on furnace design and process control.

For more information, click on the link below (subscription required). Then scroll to Figure 14

R Schneider ; R. Mesquita ; H. Altena ; T. Müller ; P. Seemann,Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

One Minute Mentor: Continuous Operating Furnaces for Tool Steel Strips

The continuous heat treatment of tool steel is applied to low- or medium-alloyed carbon steel strips as well as martensitic stainless steels. The described lines produce high-quality strip with respect to uniform structure, flatness, and bright surface finish. Steel grades with 0.4 to 1.2% C, low and high alloyed, can be processed. Strip dimensions range between 10 to 750 mm (0.4 to 29.5 in.) wide and 0.05 to 4 mm (0.002 to 0.16 in.) thick. High quenching rates are necessary, especially for plain carbon steels. Cooling gradients of up to 600 K/s are possible in a molten lead-bismuth quench. Because two-stage quenching technology provides considerable advantages over quenching in oil, this method has been adopted worldwide. It is also possible to achieve isothermal transformation to bainite and pearlite using a molten metal quench, so this type of hardening and tempering line is extremely versatile.

The configuration of a high-performance line involves an entry and exit section of the strip handling equipment (Fig. 10). The hardening section consists of the austenitizing furnace, the molten metal quench or hydrogen quench, and a martensite cooler. Beyond the martensite cooler the strip is martensitic and fully hardened, and then it passes through the tempering section—consisting of a leveling furnace, tempering furnace equipped with an atmosphere recirculation system, and an atmosphere jet cooler—to finally leave the facility, completely flat, with a bright surface finish and tempered to very uniform tensile strength.

For more information, click on the link below (subscription required). Then scroll to Figure 10

R Schneider ; R. Mesquita ; H. Altena ; T. Müller ; P. Seemann,Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

Multi-furnace heat treat project for major steel forger

Nutec Bickley, Mexico, has been awarded a contract to manufacture and install five new lift-up furnaces, along with a fully modernized combustion system, for a leading U.S. manufacturer of high-quality alloy steel and carbon steel closed-die forgings. The project will take place between May and December 2023, with onsite work completed one furnace at a time to ensure the customer’s production schedules are not impacted. Two of the new furnaces will be used for tempering, while the remaining three will be used for austenitizing. Each furnace will be fitted with the latest control systems, complete fiber flues, and new exhaust and pressure control systems, along with insulation.

Nutec Bickley’s state-of-the-art combustion packages will be fully compliant with NFPA 86 standards, incorporating a fuel-only control system to allow maximum temperature uniformity potential for all cycles. The retrofitted furnaces will benefit from high-velocity nozzle mixing burners fitted with high-temperature burner blocks. The combustion systems will also feature automatic air control valves to adjust the maximum air volume used and to ensure proper burner ignition conditions.

The project will involve careful teamwork between the customer and Nutec Bickley to ensure successful delivery and highest quality outcomes. Rodrigo González, VP Metals at Nutec Bickley, emphasized the importance of constant communication and status updates with customers for a dynamic and mutually beneficial project result.

 

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Ipsen repurposes ceramics facility for expanded hot zone production capacity

Ipsen, Pecatonica, Ill., formerly known as Ipsen Ceramics, is expanding its vacuum furnace hot zone assembly. The refurbishments include new lighting, HVAC, roofing, and other interior and exterior upgrades. Located at 325 John Street, less than 30 miles from Ipsen’s Vacuum Technology Excellence Center in Cherry Valley, the factory will initially employ up to eight material assemblers.

Incorporating the Pecatonica location into Ipsen’s vacuum furnace production and aftermarket process will provide added benefits to customers. Jake Hamid, Ipsen’s director and chief Operating Officer, stated that “Our goal is to reduce delivery times and better control the critical phase of assembly.” In the future, Ipsen is considering other manufacturing activities in Pecatonica to supplement the needs of the Vacuum Technology Excellence Center.

The move to repurpose the Pecatonica plant aligns with Ipsen’s commitment to providing high-quality vacuum furnace equipment and services to customers. The company’s dedication to meeting customer needs and reducing delivery times will be further enhanced by this strategic move, ensuring that Ipsen remains a leader in the vacuum furnace industry.

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