1, induction heating devices

Heat treatment induction heating devices are generally composed of power supply, inductor and fire.

a. Inductive power

The main parameters of an inductive power supply are frequency and power.

At present, China is inductive power supply is both new and old. The main body of the old high-frequency and super audio power supply is a high-power electronic oscillator, which converts 50Hz power frequency current into 100-500kHz high frequency and 30-50kHz super audio. Its main disadvantages are low frequency conversion efficiency and short life of the oscillator.

The old intermediate frequency power supply is the 1 kind of machine-type intermediate frequency generator, the main disadvantage is low efficiency and high equipment cost. The above two types of power supply will gradually be replaced by transistor type medium and high frequency power supply.

Transistor thyristor intermediate frequency power supply uses thyristor elements to convert 50Hz power frequency three-phase alternating current into single-phase medium alternating current, which is characterized by high efficiency and convenient control.

The new all-solid-state high-power supply uses a new power electronic device electrostatic induction transistor (SIT) to make the device all solid-state. It has the advantages of high conversion efficiency, low working voltage, safe operation, long service life and high voltage rectifier transformer, but the equipment cost is high.

50Hz industrial frequency video game is an industrial transformer, no frequency conversion device is required. Its equipment is simple. The output power is large, and the surface quenching or diathermy of sub-large workpieces is applied. The main disadvantage is that the heating speed is low and the heating efficiency is low.

 B. Inductors

Induction heating is only possible with an inductor. The structure and size of the inductor vary with the characteristics of the workpiece and the power supply rate. the inductor seriously affects the quality and thermal efficiency of the induction heat treatment of the workpiece.

& nbsp; & nbsp; c. Induction hardening machine

The induction hardening machine mechanizes induction heat treatment and facilitates accurate control of process parameters. It has two kinds of ordinary type and special type, special machine tool is designed according to the heat treatment requirements of a workpiece.

D. induction heating production line

modern production organizations often place induction heat treatment on the machining line to form a production line. at this time, the induction heating device is a special complete set of equipment, including induction power supply and multi-station quenching machine tools. Equipment cooling and crushing fire medium circulation system, inductor, induction tempering, workpiece correction deformation device and computer control system.

2, flame heating device

, it is generally composed of acetylene generator, burner and quenching machine tool. The flame temperature can be as high as 2000-3000 ℃. The heating device is simple in equipment and low in production cost. The disadvantage is that process parameters such as temperature are difficult to control and are usually used in single-piece and on-site large-scale production.

3, contact resistance heating device

Contact resistance heating device is composed of power transformer, movable contact roller (copper roller or carbon rod) and machine tool. The operation is to connect rollers at both ends of the secondary side of the transformer as the two poles of the electrode. The rollers roll on the working surface, generating local resistance on the contact surface and heating, heating the workpiece at the contact part, and then cooling and quenching by the workpiece itself. This device has a simple structure and is mostly used for surface quenching of large parts such as machine tool guides. This installation is difficult to control due to process parameters. Very few applications.

4. Direct resistance heating device

This device consists of a power transformer, an energized chuck and a machine tool. The two electrode chucks are clamped at both ends of the part to be heated. The workpiece at this part is heated by low voltage and high current. The structure of the chuck has a fixed type and a sliding type. Some devices use two rollers to replace the chuck, the two rollers press the workpiece tightly, roll in parallel, and heat the workpiece between the rollers. The heating device has a simple structure and high thermal efficiency. Widely used in steel wire, steel ordinary electric heating.

5. Electrolyte heating device

This heating device consists of DC power supply, electrolyte tank and workpiece holding device. The heated workpiece is connected to the cathode of the power supply, immersed in the electrode liquid tank, and the tank body is connected to the anode of the power supply. Electrolysis occurs by electricity, and a hydrogen film is formed on the surface of the workpiece during electrolysis. This film generates heat due to high resistance value and heats the workpiece. This device is generally applied to the local heating of small workpieces with simple shapes, such as the heating of the end of the valve lifter. It is easy to overheat the workpiece with acute angle. This device is not used much.

6, plasma heating device

& nbsp; & nbsp; This device consists of a vacuum vessel, a workbench, a plasma-generating gas source, a supply and exhaust line and a control circuit. The workpiece is placed on the worktable in the vacuum container, connected to the power cathode, and the container is connected to the power anode. The control circuit ionizes the gas in the low vacuum to produce plasma, and the plasma impacts the workpiece at high speed under the action of the electric field, converting its kinetic energy into heat energy and heating the workpiece. This device is mainly used for chemical heat treatment such as nitriding, and its advantage is that the plasma itself is the ions of the seepage agent such as N,N & rsquo; When impacting the workpiece, the passivation film on the surface of ICBC is sputtered off and penetrates into the workpiece, with a higher seepage rate and a denser seepage layer.

7, laser heating cover

This device consists of laser, light guide system, workbench and control system. The high energy density laser beam scans on the workpiece, the workpiece is heated, and then the workpiece is cooled and quenched by itself. This device has high productivity, fast heating speed, and high hardness after quenching. It is a heating device under development. Used in cylinder liner, gear, guide rail and other workpiece quenching.

8, electron beam heating device

This device consists of electron beam generator, scanning system, low vacuum chamber and control system. The high-speed electron beam current scans bombard the workpiece placed on the table in the vacuum chamber to heat it. Subsequently, the workpiece is cooled and quenched by itself. This device is beginning to be put into practical use.