Technologies

induction heating steel casting

induction heating steel casting of rubber mold with high frequency induction heater

Objective To preheat two irregularly shaped steel castings to be molded and bonded with synthetic rubber
Material Two steel castings, 17 lb. irregularly shaped, approximately 6” (152mm) x 9” (229mm) x 1” (25.4mm)
Temperature 400 ºF (204 ºC)
Frequency 20 kHz
Equipment • DW-MF-45kW induction heating system, equipped with a remote workhead containing four 1.0 μF capacitors (for a total of 1.0 μF).
• An induction heating coil designed and developed specifically for this application.
Process Two steel castings are placed onto an insulated plate with brass guide location pins. The plate is placed onto a table which slides into a large multi-turn helical coil. The parts are induction heated to 400 ºF in 180 seconds. The slow heating time allows the parts to come up to temperature evenly. When the heating cycle is completed each part is placed into a press for the molding and bonding operation.
Results/Benefits Induction heating for bulk preheating of steel castings
produces:
• efficient and repeatable heat vs. a torch or an oven.
• even heating of parts throughout
Large multi-turn coils provide:
• easy loading and unloading of the parts
• flexibility for varying bulk castings sizes and geometries

induction heating steel cable for cutting

induction heating steel cable for cutting with radio frequency heating equipment

Objective Prior to cutting, heat a short section of a hardened steel cable coated with a polyethylene sheathing.
Material Multi-strand braided stainless steel cable 0.5 in. (1.27 cm) OD enclosed within a polyethylene sheathing
Temperature 1800 ºF (982) ºC
Frequency 240 kHz
Equipment • DW-UHF-20kW induction heating system, equipped with a remote workhead containing four (4) 1.0 μF capacitors (for a total of 1.0 μF).
• An induction heating coil designed and developed specifically for this application.
Process A three-turn helical coil is used to heat the cable in approximately 2 seconds. After the power is turned off, the heat is then transferred to the sheathing.
Results/Benefits Induction heating provides a quick, precise repeatable method to reach the high temperature required. It is a very efficient heating method.

 

induction sealing glass

Induction sealing glass to enclose resistors with high frequency induction heating system

Objective Provide a hermetic seal of glass enclosed resistor to a lead
Material Resistor Kovar rings, 0.1 inch (0.254cm) diameter Glass tube slightly larger than 0.1 inch (0.254cm) diameter, 0.5 (1.27) inch length
Metal lead
Temperature 900 ºF (482) ºC
Frequency 324 kHz
Equipment • DW-UHF-6kW-III induction heating system, equipped with a remote workhead containing two (2) 1.5 μF capacitors (for a total of 0.75 μF).
• An induction heating coil designed and developed specifically for this application.
Process A three turn concentrator plate coil is used to heat the Kovar ring for 500 milliseconds. This causes the glass to melt and seal one side of the resistor. The resistor is then turned over
and the process is repeated to seal the other side using a second Kovar ring.
Results/Benefits Induction heating provides precise, consistent heat to very small parts resulting in repeatable, quality seals.
By heating with medium frequency, arcing (which occurs at high frequencies) is avoided.

 

Induction Tempering Spring

Induction Tempering Spring with High Frequency Induction Heating Equipment

Objective Temper a spring by heating it to 300°C (570°F) in 2 – 4 seconds
Material Stainless steel AISI 302 springs- different length from 60 to
110 mm – outer diameters 8 mm.- wire diameter from 0.3 to 0.6 mm
Temperature 300°C (570°F)
Frequency 326 kHz
Equipment • DW-UHF-10kW induction heating system
• remote workhead, two 0.33μF capacitors (total 0.66μF)
• multi-turn C-channel coil developed for this application
Process Springs are mounted on non-metallic mandrels to facilitate loading and unloading and are placed inside the coil (picture). Power is applied for 2 – 4 seconds, completing the tempering process. The C-channel distributes the heating evenly and enables the convenient staging and removal of the springs.
Results/Benefits Efficiency: Energy is applied directly to the springs only;surrounding air and fixturing are not heated.
Precision: temperature and duration of process are controlled
Convenience: method integrates into a continuous process

 

Induction Heating Valve Head

Induction Heating Valve Head For Stress Testing With Induction Heating Equipment

Objective To heat the face of an engine valve head to 900°F and maintain the temperature for an extended time, high temperature stress test.
Material Engine valve head (two sizes), temperature sensing paint
Temperature 900 °F
Frequency200 kHz for large part; 271 kHz for smaller part
Equipment DW-UHF-10KW Induction Heating power supply, remote heat station with one 0.66 mF capacitor, a specially designed, multiturn induction coil and an optical pyrometer.
Process A specially designed multi-turn pancake coil was used to provide uniform heat to the part. To provide optimum coupling, the face of the valve head was placed approximately 3/8” away from the coil. RF induction power was applied for 4 minutes to heat the larger valve to 900°F; the smaller valve head required 2 minutes to reach the same temperature. For closed-loop temperature control, the optical pyrometer was then used to maintain the temperature at 900°F.
Results Uniform and repeatable results were obtained with the
DAWEI power supply and induction coil at 900°F. Depending on the part size, the correct temperature was reached in 2 to 4 minutes.

Induction Annealing Aluminum PIpe

Induction Annealing Aluminum PIpe With High Frequency Induction Heating Machine

Objective Annealing aluminum fuel tank fill neck to 650 ºF (343 ºC)
Material Aluminum fill neck 2.5” (63.5mm) diameter, 14” (35.5cm) long
Temperature 650 ºF (343 ºC)
Frequency 75 kHz
Equipment •DW-HF-45kW induction heating system, equipped with a remote workhead containing eight 1.0μF capacitors for a total of 2.0μF
• An induction heating coil designed and developed specifically for this application.
Process An eight turn helical is used to heat the tube for annealing. To anneal the full length of the tube, the tube is placed in the coil and heated for 30 seconds then rotated and the bottom half is heated for an additional 30. The tube is then bent while hot to prevent cracking.
Results/Benefits Induction heating provides:
• High efficiency, low energy cost
• Fast, controllable and repeatable process
• Prevention of cracks
• Hands-free heating that involves no operator skill for manufacturing
• Even distribution of heating

 

 

Induction annealing copper wires

Continuous Induction annealing copper wires with High frequency heating system

Objective Continuously anneal a copper wire used in electric motors at a rate of 16.4 yds (15m) per minute to eliminate work hardening caused during the drawing process.
Material Square copper wire 0.06” (1.7mm) dia., temperature indicating paint
Temperature 842 ºF (450 ºC)
Frequency 300 kHz
Equipment • DW-UHF-60kW induction heating system, equipped with a remote workhead containing eight 1.0μF capacitors for a total of 8.0μF
• An induction heating coil designed and developed specifically for this application.
Process A twelve turn helical coil is used. A ceramic tube is placed inside the coil to isolate the copper wire from the copper coil and to allow the copper wire to flow smoothly through the coil.
Power runs continuously to anneal at a rate of 16.4 yds (15m) per minute.
Results/Benefits Induction heating provides:
• Hands-free heating that involves no operator skill for manufacturing
• Flameless process
• Ideal for in-line production processes

Induction Annealing Aluminum

Induction Annealing Aluminum With High Frequency Heating System

Objective Annealing a 1” lip on aluminum cryogenic dewar that has been work hardened during the process of spin forming.
Material Aluminum dewar, lip has a 3.24” (82.3mm) ID and is 0.05” (1.3mm) thick
Temperature 800 ºF (427 ºC)
Frequency 300 kHz
Equipment •DW-UHF-10KW induction heating system, equipped with a remote workhead containing one 1.0 μF capacitor.
• An induction heating coil designed and developed specifically for this application.
Process A two turn helical coil is used to heat the lip on the cryogenic dewar. The dewar is placed in the coil and power is applied for 2 minutes to anneal the required 1” heat zone.
Results/Benefits Induction heating provides:
• Hands-free heating that involves no operator skill for manufacturing
• Fast, controllable, accurate heating
• High efficiency, low energy cost
• Even distribution of heating

 

Induction Annealing Stainless Steel Tubes

Induction Annealing Stainless Steel Tubes With High Frequency Heating Equipment

Objective To anneal a ¼” area around an oval cutout on a stainless steel tube prior to extrusion
Material .75” (19mm), 1.5” (38.1mm) and 4” (101.6mm) diameter steel tubes
Temperature 1900 ºF ( 1038 ºC)
Frequency 300 kHz
Equipment • DW-UHF-20kW induction heating system, equipped with a remote workhead containing one 1.0μF capacitor.
• An induction heating coil designed and developed specifically for this application.
Process A single turn helical coil is used on the 4” (101.6mm) diameter tubes and a two turn helical coil is used on the smaller diameters. The coil is placed over the oval cutout and power is
supplied for 15 seconds to anneal a .25 (6.35mm) diameter around the cutout.
Results/Benefits Induction heating provides:
• Precise and controllable placement of heat to anneal only the required area
• Faster process than flame
• Repeatable results
• Hands-free heating that involves no operator skill for manufacturing

Annealing Stainless Steel Tubes

 

=