Heating systems for bars and billets

Induction heating of bars and billets for the forging industry

Induction heating systems have assumed an increasingly prominent role in the forging industry. The main reasons for this success are due to the precise control of the transferable energy and the final temperature in the workpiece during heating.

The power density transferable to the material being heated is significantly higher compared to other heating technologies and allows the production of compact systems with high productivity rates.

Typical problems, such as surface oxidation, calamine formation, decarburisation and grain growth, can be significantly reduced due to the short heating time. High levels of productivity are ensured by a higher degree of automation and low rates of waste parts.

Continuous heating of aluminium alloy ingots

Section profile: 1532 mm²
Temperature: up to 560° C
Hourly production: up to 3000 kg / h

Intermediate induction heating in rolling mills for the hot production of steel

The steel rolling process in the plastic field consists of a combination of mechanical deformations and metallurgical transformations, which are sensitive to the temperature of the workpiece being processed.

In a rolling mill, the distribution of the temperature in the material in the entrance of the first rolling cage of the rolling mill is extremely important to obtain end products with convenient properties.

The billets arrive at the first cage of the outgoing rolling mill or from a gas-fired furnace or directly from continuous casting.

The path the billets must cover from the exit of the gas furnace or from the continuous casting to the first cage of the intermediate rolling mill depends on how long the layout of the rolling mill is.p>

DEven if the billet moves along insulated rollers, it releases heat by conduction to the transport rollers and by convection and irradiation to the surrounding ambient and, consequently, cools down.

The differences in temperature that are established between the surface and the core and between the head and the tail during the transfer process to the first cage do not allow the rolling of the all the material at an even and optimal temperature; the purpose of introducing the inline induction heaters in the area upstream to the rolling mill, is the equalisation of the temperature distribution in the radial and transverse longitudinal sections of the billets.

Induction heating furnace for steel bars and billets

Bars diameter: up to 100 mm
Output temperature: up to 1300° C

Steel billet heating – multi pass

Size of the billets: up to 140 x 140 mm
Output temperature: up to 1100° C

Induction heating for subsequent hot rolling of steel and aluminium bars

The use of induction heating for subsequent rolling of steel or aluminium bars is a practice that is spreading among producers of hot-rolled sections that use small rolling mills.

The power density transferable to the material being heated is significantly higher compared to other heating technologies and allows the production of compact systems with high productivity rates.

Induction heating furnace for aluminium alloy ingots

Base: 39,9 mm
Height: 33,5 mm
Speed: 0,25 m/1'
Temperature: up to 550° C

Induction heating furnace of aluminium section bars

Section profile: Trapezium section 2500 mm²
Maximum speed: 0,22 m / s
Temperature: up to 600° C

Continuous heating of steel wire rods and bars for further hot-rolling

Steel bars: up to 33 mm
Steel wires: up to 22,5 mm
Temperature: Rated value 1000 °C at the furnace exit

Hardening and tempering of flat steel bars

The advantages of induction heating compared to other systems are the high thermal efficiency, fast heating in small spaces and easy control of operating parameters that allow to obtain precise metallurgical characteristics that are repeatable and constant over time.

All the above-mentioned factors are at the base of the success of induction furnaces for the heat treatment of inline hardening and tempering of flat bars for the subsequent production of forks for forklift trucks.

Continuous preheating of plates to power a gas-powered hardening furnace

Materials : alloyed steels to boron for tempering and hardening
Shape and size of sections to be heated: “plates” with a flat side and other variously rounded
- Width: up to 406 mm
- Thickness: up to 41 mm
Heating temperature: from room temperature to 500° C (on the surface)