Medium-Frequency Heater: Efficient Heating Equipment for Metal Forging and Hot Forming
In the field of metal forging and hot forming, the heating process directly affects the forming quality, production efficiency, and material utilization of workpieces. Medium-frequency heaters (usually operating at a frequency of 1-10kHz), with their advantages of rapid temperature rise, uniform temperature distribution, and concentrated energy, have become core heating equipment in this field. They are particularly suitable for forging preheating, die forging heating, and hot stamping forming processes of various steel, aluminum alloy, titanium alloy, and other metal materials.
| Model |
60KW Induction Preheating PWHT Machine |
| Input Voltage |
3 Phase 380V, 50HZ |
| Output Frequency |
5KHZ ~ 30KHZ |
| Output Power |
60 KW |
| Input Current |
0-90A |
| Cooling Type |
Air cooling |
| Heating Temperature |
Preheat 0 - 350 C |
| Temperature Control |
1 Channel or 4 Channel |
| Heating Pipe size |
Dia: 50 -1000 mm |
| Heating Coil |
Induction Coil, Heating Blanket, Clamp Induction Coil |
| Extend cable |
1-20 meter |
| Heating Blanket |
Induction heating blanket, High temperature tube |
| Alarm |
Over Voltage, Over Current, Over Temperature and so on |
Core Functions: Meeting High-Temperature Heating Requirements for Forging and Hot Forming
Metal forging and hot forming require heating materials to the forging temperature range (e.g., 800-1250°C for carbon steel, 350-500°C for aluminum alloys, 800-1050°C for titanium alloys) to improve material plasticity and reduce deformation resistance. Medium-frequency heaters precisely adapt to process requirements through the following functions:
- High-temperature precise control: Adopting a closed-loop temperature control system, combined with infrared temperature measurement or thermocouple feedback, the heating temperature can be controlled within ±10°C. For example, when heating 40Cr alloy steel for die forging, it can stably maintain at 1100°C ± 5°C, avoiding grain coarsening caused by excessive temperature or forging cracking due to insufficient temperature.
- Rapid penetration heating: The penetration depth of medium-frequency current (usually 1-10mm) is suitable for heating medium and thick workpieces. Through electromagnetic induction, the material is heated synchronously from the surface to the core, achieving overall uniform heating. For round steel with a diameter of 100mm, it only takes 8-12 minutes to heat from room temperature to 1000°C, which is more than 60% more efficient than traditional coal-fired heating.
- Adapting to batch and single-piece production: It supports continuous heating (such as continuous feeding of blanks in forging production lines) and intermittent heating (such as single-piece heating of large forgings). It can adapt to workpieces of different sizes by adjusting the power output (usually 50-500kW), ranging from small-sized bars with a diameter of 10mm to large blanks with a thickness of 500mm, all of which can be heated efficiently.
Technical Advantages: Core Competitiveness Surpassing Traditional Heating Methods
Compared with traditional heating methods such as coal-fired, gas-fired, and resistance heating, medium-frequency heaters show significant advantages in metal forging and hot forming:
- Heating efficiency and energy saving: The heat conversion efficiency reaches 70%-85%, much higher than coal-fired heating (about 30%) and resistance heating (about 50%), which can reduce energy costs by 30%-50%. At the same time, there is no open flame or smoke during the heating process, reducing heat radiation loss and meeting environmental protection requirements (such as ultra-low nitrogen emissions).
- Temperature uniformity ensures forming quality: Through the design of multi-turn induction coils and magnetic field optimization, the radial temperature difference of the workpiece can be controlled within ±20°C, avoiding forging defects (such as cracks and folds) caused by local overheating. For example, when heating a stepped shaft blank with an aspect ratio of 5:1, the temperature deviation of each section is ≤15°C, ensuring uniform mechanical properties after forging.
- Reducing oxidation burning loss: The rapid temperature rise characteristic shortens the residence time of materials in the high-temperature zone, and the oxidation burning loss rate can be controlled below 0.5% (traditional gas heating is usually 2%-5%). It is especially suitable for forging of precious metals or high-alloy materials, reducing material loss.
Application Scenarios: Covering Forging and Hot Forming Processes in Multiple Fields
The adaptability of medium-frequency heaters makes them widely used in various metal hot working scenarios:
- Free forging: Overall heating of large steel ingots and shaft parts, such as sectional heating of wind power main shaft forgings (weight 5-50 tons). The moving induction coil is used to realize step-by-step temperature rise of the blank, meeting the temperature requirements during the forging process.
- Die forging forming: In the production of batch die forgings such as automobile connecting rods, gear blanks, and bearing rings, medium-frequency heating is used to achieve rapid temperature rise and constant temperature maintenance of blanks, ensuring stable temperature when entering the die, improving die life and forging dimensional accuracy.
- Hot stamping forming: For the hot forming process of high-strength automobile steel plates (such as 22MnB5), the steel plates are heated to 900-950°C and kept warm to make them fully austenitized, then quickly transferred to the die for stamping, obtaining ultra-high strength (above 1500MPa) body structural parts.
- Aluminum alloy forging: Low-temperature forging heating (380-450°C) is performed on aerospace aluminum alloy forgings (such as 7075 and 2024 alloys). The temperature is precisely controlled to avoid overburning, and at the same time, the rapid temperature rise reduces grain growth, ensuring the mechanical properties of the forgings.
Equipment Features: Practical Design Adapting to Industrial Production
- Modularity and scalability: Adopting a split design (separation of host and induction coil), it can be configured with single-station or multi-station heating systems according to production needs, supporting linkage with forging production lines and robot loading and unloading systems to realize automated production.
- Intelligent process management: Equipped with a PLC control system and touch screen, it can store more than 100 kinds of heating process parameters (such as temperature curve, holding time, power curve), supporting encryption and traceability of process parameters to ensure the quality consistency of products in different batches. For example, for forging processes of different steel grades, preset parameters can be called with one click, reducing manual debugging time.
- Durability and safety: The induction coil is made of high-temperature resistant copper material and insulating material (such as mica, ceramics), which can withstand long-term work at temperatures above 1200°C; the equipment is equipped with overcurrent, overvoltage, water shortage, and overtemperature protection devices to ensure safe and stable operation in harsh industrial environments.
Medium-frequency heaters, with their efficient, energy-saving, and precise heating capabilities, have become indispensable key equipment in modern metal forging and hot forming industries. They not only improve production efficiency and product quality but also promote the upgrading of metal processing to green, intelligent, and high-quality directions, creating significant economic and environmental benefits for enterprises.
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