DW-HF-120KW Magnetic Induction Heating Equipment for Industrial Metal Heating

Quick Answer

What is the DW-HF-120KW Magnetic Induction Heating Equipment?

The HLQ DW-HF-120KW is a high-frequency induction heating system designed for industrial metal heating, surface hardening, brazing, annealing, shrink fitting, and selected localized heat-treatment applications. The manufacturer’s published specifications include a maximum oscillating-power rating of 120kVA, a maximum input apparent-power rating of 130kVA, an operating frequency range of 30–80kHz, and a three-phase 380V, 50/60Hz electrical supply. The system uses IGBT inverter technology, a separated main power unit and extension unit, and application-specific water-cooled induction coils.

Best-Fit Applications: Gear and shaft surface hardening, induction annealing of steel tubes, industrial tool brazing, copper and brass joining, localized pipe heating, thermal shrink fitting, and production-line heating of compatible metal components.

Engineering Selection: The correct induction heating system must be selected according to workpiece material, dimensions, effective heated mass, target temperature, heating depth, required cycle time, operating frequency, coil configuration, and cooling conditions. The published 120kVA oscillating-power rating must not be interpreted as a guaranteed 120kW of useful heat absorbed by a workpiece.

Table of Contents

1. What Is the DW-HF-120KW Magnetic Induction Heating Equipment?
2. Key Applications
3. Suitable Materials
4. Working Principle
5. Technical Specifications
6. Recommended Model Selection
7. Process Workflow
8. Common Problems and Solutions
9. Engineering Selection Guide
10. Advantages and Limitations
11. Why Choose HLQ?
12. 10 Core FAQs

What Is the DW-HF-120KW Magnetic Induction Heating Equipment?

The DW-HF-120KW Magnetic Induction Heating Equipment is an industrial electromagnetic heating system that uses high-frequency alternating current to generate heat within electrically conductive metal components.

The equipment is intended for applications requiring localized or controlled heating, including surface hardening, brazing, annealing, thermal assembly, and selected manufacturing processes.

The high-frequency inverter supplies electrical energy to a resonant heating circuit connected to an induction coil. When a conductive workpiece is positioned within the coil’s alternating magnetic field, electrical currents are induced inside the material.

Electrical resistance converts these currents into heat. The resulting temperature distribution depends on the material, induction frequency, coil geometry, coupling distance, and heating duration.

Although the product name includes the word “magnetic,” the equipment can heat both ferromagnetic and nonferromagnetic conductive metals. Copper, brass, aluminum, stainless steel, and carbon steel can all be considered for induction heating when the system is correctly matched to the application.

The DW-HF-120KW uses a separated equipment arrangement. The main power cabinet can be positioned away from the immediate heating area, while the extension unit and induction coil can be incorporated into a suitable industrial workstation.

Main Components of the DW-HF-120KW System

Split-Type Induction Heating Equipment

A separated induction heating system allows the main power supply and the workpiece heating station to be installed in different positions.

This can improve installation flexibility in workshops where dust, heat, vibration, or limited operating space affect equipment layout.

The permitted cable length, electrical matching, cooling circuit, and mechanical installation must be verified before changing the equipment arrangement.

Key Applications

The DW-HF-120KW can be considered for different industrial metal-heating processes. However, the correct operating conditions must be selected for each workpiece and application.

1. Induction Surface Hardening of Gears and Shafts

Induction surface hardening uses electromagnetic induction to heat selected surface regions of suitable steels before quenching.

The objective is to produce a hardened surface layer while maintaining the required mechanical properties of the underlying material.

Depending on the workpiece geometry, the system may use an encircling coil, scanning coil, gear-profile coil, or another application-specific inductor.

The final hardness and hardened case depth depend on steel grade, heating temperature, frequency, heating duration, coil configuration, and quenching conditions.

Suitable applications may include selected gears, shafts, pins, splines, sprockets, and other wear-resistant components.

For complete equipment configurations with quenching and workpiece motion, review HLQ’s induction hardening machine solutions.

2. Industrial Brazing of Metal Components

The equipment can be evaluated for joining compatible copper, brass, steel, stainless steel, and carbide assemblies through induction brazing.

The heating system must provide the required joint temperature without intentionally melting the base metals.

Filler metal selection, surface preparation, joint clearance, flux or protective atmosphere, and controlled cooling are essential to brazing quality.

3. Induction Annealing of Steel Tubes

Induction annealing involves heating selected metal components according to a defined metallurgical thermal cycle.

For steel tubes, the induction coil should be designed according to outer diameter, wall thickness, heated length, material grade, and required temperature distribution.

The final material condition depends on heating temperature, holding time, cooling rate, and the applicable material specification.

4. Induction Heating for Thermal Shrink Fitting

Induction heating can be used to expand suitable metal components before assembly.

Typical applications include gears, bearing housings, sleeves, coupling components, and other interference-fit assemblies.

The heating temperature should be calculated from the required expansion, material thermal expansion coefficient, interference allowance, and component geometry.

5. Industrial Tool Brazing

Selected cutting tools, diamond segments, and carbide components can be joined to suitable metal bodies using qualified brazing processes.

Coil geometry and filler-metal selection are critical because the joining materials may have different electromagnetic, thermal, and mechanical properties.

6. Localized Pipe and Tube Heating

Induction heating can be used for selected pipe and tube heating operations, including local annealing, preheating, coating-related processes, and thermal assembly.

For larger pipe diameters, the suitable operating frequency and power supply configuration should be evaluated carefully.

7. Forging Preheating

Induction heating may be used to preheat metal bars or selected forging regions before hot forming.

However, the high-frequency DW-HF-120KW should not automatically be selected for large-diameter through-heating applications.

For thicker billets and deeper heating requirements, a medium-frequency system may offer a more suitable electromagnetic heating arrangement.

8. Selected Metal Melting Applications

Small or specialized metal-melting operations may be possible with an appropriate induction furnace, crucible, and matching system.

The DW-HF-120KW rating does not establish a universal metal-melting capacity.

Metal type, charge mass, melting temperature, crucible design, frequency, and thermal losses must be evaluated before selecting a melting system.

Suitable Materials

Induction heating can be applied to electrically conductive materials, including ferromagnetic and nonferromagnetic metals.

The heating behavior depends on electrical resistivity, magnetic permeability, thermal conductivity, specific heat capacity, material geometry, and temperature.

Material Properties Affecting Heating Performance

Working Principle

The DW-HF-120KW operates according to electromagnetic induction.

Incoming three-phase electrical power is converted by the power electronics into high-frequency alternating current.

This current flows through an induction coil, creating a changing magnetic field around the workpiece.

The magnetic field induces electrical currents inside electrically conductive materials.

The resistance of the material converts the induced currents into heat.

In suitable ferromagnetic materials, magnetic losses can also contribute to heating under certain conditions. As the material temperature increases, its magnetic and electrical properties may change significantly.

Electromagnetic Induction Heating Sequence

Induction Frequency and Heating Depth

The original DW-HF-120KW product page lists an induction frequency range of 30–80kHz.

Operating frequency influences the distribution of induced electrical currents within the workpiece.

Under simplified electromagnetic conditions, increasing frequency reduces the reference electrical skin depth.

The reference skin depth can be estimated using:

δ = √[ρ / (π × f × μ)]

Where:

• δ = Electrical skin depth, meters.
• ρ = Electrical resistivity, Ω·m.
• f = Operating frequency, Hz.
• μ = Absolute magnetic permeability, H/m.

Important: Electrical skin depth is not identical to final temperature penetration depth or hardened case depth. Heat conduction, heating duration, material geometry, and temperature-dependent electromagnetic properties also affect the resulting heating pattern.

Induction Coil Design

The induction coil is a critical component of the heating system.

Its geometry, number of turns, active heating length, and coupling distance influence electromagnetic heating efficiency and temperature distribution.

Different applications require different coil designs. A coil optimized for shaft hardening may not be suitable for copper brazing or tube annealing.

For detailed electrical and mechanical inductor selection, see HLQ’s custom induction heating coil design guide.

Technical Specifications

The following specifications preserve the values published on the original HLQ product page.

Parameters requiring additional verification are clearly identified.

DW-HF-120KW Published Technical Specifications

Specification Differences Requiring Confirmation

Understanding the 120kVA and 130kVA Ratings

The product name contains “120KW,” but the original manufacturer’s specification lists 120kVA as maximum oscillating power.

Apparent electrical power, active electrical power, inverter output power, and useful workpiece heating power are different quantities.

Three-Phase Electrical Current Calculation

For a balanced three-phase electrical system:

S = √3 × Vline × Iline

Where S is apparent electrical power, Vline is line-to-line voltage, and Iline is line current.

Using a theoretical input apparent power of 130kVA at 380V:

Iline = 130,000 / (√3 × 380) ≈ 197.5A

This is a reference electrical calculation, not a verified DW-HF-120KW input-current measurement. Actual electrical installation must follow the manufacturer’s confirmed specifications and applicable regulations.

Cooling System Requirements

The DW-HF-120KW is a water-cooled industrial induction heating system.

The cooling circuit must remove waste heat generated in the coil and designated power components.

The published flow of at least 6L/min must be verified before selecting a cooling unit, particularly for continuous industrial operation.

Illustrative Cooling Water Heat Removal

The theoretical heat removed by a cooling-water circuit can be estimated using:

P = mflow × Cp × ΔT

For an illustrative water flow of 6L/min and a temperature increase of 8°C, the calculated heat removal is approximately 3.34kW.

This is an engineering calculation, not a measured cooling load for the DW-HF-120KW.

It must not be used as the only basis for selecting a cooling system.

Recommended Model Selection

Industrial induction heating equipment should be selected according to the workpiece and required thermal process rather than rated power alone.

Operating frequency, heated mass, coil geometry, target temperature, production rate, and cooling requirements must be evaluated together.

Application-Based Model Selection

Selection Qualification: The equipment classes above are preliminary screening recommendations. They are not guaranteed workpiece-size, heating-time, or production-capacity ratings.

High Frequency vs. Medium Frequency Induction Heating

For metal billets and bars requiring a different heating-depth arrangement, compare HLQ’s induction forging bar and billet furnace equipment.

Process Workflow

The industrial induction heating process requires material preparation, workpiece positioning, power supply inspection, cooling verification, controlled heating, and application-specific quality inspection.

General Induction Heating Process

Induction Surface Hardening Workflow

For induction hardening, suitable steel components are heated to the required austenitizing condition and then quenched according to the approved metallurgical process.

The process must control the heated zone, temperature, heating duration, quench delay, quench medium, and cooling uniformity.

Steel Tube Induction Annealing

For tube annealing or localized heating, the induction coil and fixture should provide an appropriate temperature distribution over the required region.

Tube diameter, wall thickness, material grade, heating duration, and cooling conditions determine the actual process.

Production Control and Automation

Induction heating can be incorporated into manual, semi-automatic, or fully automated industrial production systems.

Depending on the application, the overall production line may require a PLC, temperature measurement, workpiece positioning, conveyor movement, scanning mechanisms, or a quenching station.

The exact controller, communication interface, and automation functions must be confirmed for the supplied equipment.

Common Problems and Solutions

Industrial induction heating problems may result from electrical matching, coil geometry, material variation, inadequate cooling, inaccurate positioning, or incorrect heating parameters.

Engineering Selection Guide

Correct equipment selection requires evaluation of the complete heating process, including material, geometry, temperature, heating time, production capacity, electrical supply, and cooling conditions.

Step 1: Identify the Material

Specify the exact material grade and its relevant electromagnetic and thermal characteristics.

Step 2: Confirm Workpiece Dimensions

Determine the workpiece diameter, length, wall thickness, total weight, and effective heated region.

Step 3: Define the Heating Objective

Specify whether the process requires surface hardening, brazing, annealing, thermal assembly, or through-heating.

Different thermal objectives may require different coil designs and operating frequencies.

Step 4: Establish the Target Temperature

Determine the required process temperature according to the material and application.

For hardening, the target temperature must be selected according to the steel grade and metallurgical requirements.

Step 5: Calculate the Effective Heated Mass

For a solid cylindrical workpiece:

m = ρ × π × d² × L / 4

Where:

• m = Effective heated mass, kg.
• ρ = Material density, kg/m³.
• d = Workpiece diameter, m.
• L = Heated length, m.

Step 6: Estimate the Required Heating Energy

For a simplified sensible-heating calculation:

Q = m × Cp × ΔT

Where:

• Q = Theoretical thermal energy, kJ.
• m = Effective heated mass, kg.
• Cp = Approximate mean specific heat capacity, kJ/kg·K.
• ΔT = Temperature increase, K.

Engineering Calculation Example: Steel Component Heating

Consider an illustrative AISI 1045 steel cylinder with a diameter of 60mm and a heated length of 90mm.

Assume the metal is heated from 25°C to 850°C.

For preliminary calculations, use an approximate steel density of 7850kg/m³ and a mean specific heat capacity of 0.62kJ/kg·K.

The theoretical sensible-heating energy is approximately 1022kJ.

If the target heating time is 25 seconds, the average useful thermal power is approximately 40.9kW.

For illustration only, assuming an overall electrical-to-workpiece efficiency of 50%, the average electrical input would be approximately 81.7kW.

Important: These values are theoretical engineering estimates, not verified DW-HF-120KW performance. Actual power requirements depend on temperature-dependent material properties, metallurgical transformations, heat losses, electromagnetic coupling, and operating conditions.

Step 7: Evaluate Heating Time and Power

The calculated input power cannot be compared directly with the published 120kVA oscillating rating without establishing the actual power-rating definition and electrical operating conditions.

Step 8: Determine Production Capacity

Production capacity depends on workpiece mass, heating energy, the required number of pieces per hour, and practical loading and handling time.

For the hypothetical 1.998kg steel component described above:

Engineering Qualification: These figures are average energy-throughput estimates only. They are not guaranteed production rates or measured input power values for the DW-HF-120KW.

Step 9: Select the Induction Frequency

The operating frequency should be selected according to the material, workpiece dimensions, heating depth, and required thermal cycle.

For deep through-heating of larger sections, evaluate whether a medium-frequency system would be more appropriate.

Step 10: Design the Induction Coil

Select the coil geometry, active heating length, number of turns, mechanical clearance, and cooling arrangement.

Verify the coil’s electrical compatibility with the generator and resonant matching system.

Step 11: Confirm Electrical and Cooling Requirements

Verify the three-phase electrical supply, full-load input current, power factor, cooling-water flow, inlet pressure, temperature limits, and water quality requirements.

Step 12: Conduct Application Testing

For production applications, representative testing should verify heating time, temperature distribution, electrical operating conditions, cooling performance, and the required process result.

Application Engineering Scenario

The following scenario illustrates how a potential industrial hardening application should be evaluated.

A manufacturer requires localized induction heating of AISI 1045 steel components before quenching. The effective heated section is approximately 2kg, and the process requires controlled heating to the specified austenitizing temperature.

The engineering assessment should include the required heated length, allowable temperature gradients, target hardening pattern, quench medium, and production rate.

The DW-HF-120KW may be evaluated as an equipment candidate, but actual performance must be confirmed by application testing.

This is an engineering calculation and selection scenario, not a documented DW-HF-120KW customer acceptance test.

Recommended Factory Acceptance Tests

Advantages and Limitations

Advantages of DW-HF-120KW Magnetic Induction Heating Equipment

Limitations and Engineering Considerations

Why Choose HLQ?

HLQ Induction Equipment Co., Ltd. provides industrial induction heating equipment for brazing, hardening, annealing, forging, melting, and other metalworking applications.

The DW-HF-120KW belongs to the HLQ high-frequency induction heating equipment range.

Application-Based Equipment Selection

Equipment selection can be evaluated according to workpiece dimensions, material properties, heating temperature, required cycle time, production capacity, and available factory utilities.

IGBT High-Frequency Inverter Technology

The original product page describes IGBT inverter technology with high-frequency operation.

The actual electrical configuration should be confirmed for the delivered equipment.

Custom Induction Coil Solutions

Application-specific coil design can help adapt the heating field to the required workpiece geometry and heating zone.

Coil selection should consider electrical matching, mechanical clearance, cooling, and temperature distribution.

Industrial Process Integration

Induction heating equipment can be incorporated into suitable production systems involving fixtures, conveyors, scanning mechanisms, quenching stations, and temperature monitoring.

The actual integration scope should be defined for each manufacturing process.

Engineering Process Verification

Representative heating tests can be used to verify the required heating cycle, temperature distribution, electrical performance, and process quality.

For technical comparison across frequency and power classes, explore the HLQ induction heating power supply range.

10 Core FAQs

1. What is the DW-HF-120KW magnetic induction heating equipment?

The DW-HF-120KW is a high-frequency industrial induction heating system intended for localized heating of electrically conductive metal components. Potential applications include surface hardening, brazing, annealing, thermal assembly, and selected industrial preheating processes.

2. What is the rated power of the DW-HF-120KW?

The original manufacturer specification lists a maximum oscillating-power rating of 120kVA and a maximum input apparent-power rating of 130kVA. These values should not be interpreted as guaranteed useful workpiece heating power.

3. What electrical supply does the equipment require?

The published electrical input is three-phase 380V, 50/60Hz. Actual input current, power factor, voltage tolerance, and electrical protection requirements must be verified for the supplied configuration.

4. What is the operating frequency of the DW-HF-120KW?

The original product page lists 30–80kHz. Actual loaded frequency depends on the induction coil, electrical matching, and workpiece characteristics.

5. Can the DW-HF-120KW harden steel gears and shafts?

It can be evaluated for surface hardening of suitable steel components when combined with an appropriate induction coil, quenching system, and validated heat-treatment procedure. Final hardness and case depth depend on the material and complete process.

6. Can it heat copper, brass, and stainless steel?

Yes. Induction heating can heat electrically conductive nonferromagnetic and ferromagnetic materials. However, power transfer, heating time, and coil design depend on the actual material properties and workpiece geometry.

7. Can the DW-HF-120KW be used for large steel billet forging?

Not automatically. Large billet through-heating may require a lower operating frequency and different induction coil arrangement. Medium-frequency equipment should be considered when deep and relatively uniform heating is required.

8. How much cooling water does the equipment require?

The original product page lists at least 6L/min and a 0.3MPa pressure reference. The required total system flow, allowable pressure, cooling-water temperature, and cooling capacity must be confirmed before installation.

9. Can the equipment operate continuously?

The manufacturer publishes a 100% duty-cycle claim at an ambient temperature of 30°C. Actual continuous-duty capability depends on the applied load, cooling conditions, and equipment configuration and must be verified under defined operating conditions.

10. How do I select the correct induction heating system?

Selection should begin with material grade, workpiece dimensions, effective heated mass, target temperature, heating depth, required cycle time, production rate, electrical supply, and cooling conditions. Engineering calculations and representative application tests should be used to verify the final equipment and coil configuration.

HLQ-DW-HF-120-magnetic-induction-heating-equipment-brochure