Aluminium - heat treatment

« back to production program

Aluminium Parts Heat Processing Furnaces

Technology:

• a. heating for forging
• b. artificial ageing
• c. hardening, fast hardening

Applications:

• aircraft industry
• automobile industry

Furnaces types:

• chamber furnaces
• car-heart furnaces
• continuous conveyer furnaces
• furnaces for fast hardening

The furnace frame is made of light sectional steel. The furnace is insulated with low - mass insulating bricks and fibre felts which provides excellent economy, low thermal lost, fast heating and cooling, low weight and power input. Furnaces are fitted with fans. The air forced circulation promotes even distribution of the temperature and a faster transfer of heat to the charge. According to the required direction of flow (vertical, horizontal), fans are fitted on the ceiling or on the sidewalls. A system of suction and draught flaps provide for the furnace atmosphere exchange. A fan may be added to the system to increase the intensity of the air exchange.

On models with electrical heating, the furnace power input is switched by contactors while on larger power it is contact less, by means of solid-state relays or thyristor units. The temperature in the furnace is measured by thermocouples, thermistores or thermostats and it is controlled by digital microprocessor controllers with the control set to value, a simple ramp function or fully programmable controllers. With larger units, control is possible by a PC-based industrial automatic control unit.

In the basic design, the temperature is recorded by a dotted recorder. If required, it is possible to install a microprocessor recorder with electronic recording and data filing. Site, power input and design are assessed individually according to specific processes, the charge weight and temperature curves.

Electric

Heating elements are manufactured of quality resistance material to withstand the rated temperature and the atmosphere of the furnace. For lower temperatures, closed elements are used (heating wire poured over with insulation material in the tubes)

Gas

Burners are fitted in the equipment together with any gas distribution piping with closing valves and fittings installed as appropriate. The equipment meets the requirements regarding emissions control.

The furnace design is selected with a view to the specific requirements that should be provided for this type of heat processing. Primarily, it the temperature accurateness, intensive airflow in the working area and fast dip of the charge in the quenching medium where hardening is required. To select a car hearth or chamber furnace, the decisive criteria are typically the weight and the method of charging. The door (single-wing or double-wing) is opened manually, pneumatically or electric motor-operated, with larger furnaces, usually upward.

Furnace dimensions, rated power input and other key parameters are determined according to specific requirements of the equipment capacity.

References:

Moravan Otrokovice, LET Kunovice, Letov Praha, ACA ANP Algeria:

Fast-quenching line with a CAX hood-type furnace. A set of heat treatment equipment consists of:

• electric hood-type furnace
• mobile quenching tanks
• charging car
• controlling, checking and calibrating system

The charge is stored on a car in the handling area in front of the furnace. After it is transported to underneath the furnace, the charge is fixed to a lifting gear and lifted to the working area. After the heat treatment is completed the quenching tank is taken underneath the furnace and the charge is quenched

General Electric:
Engine Service, Veresegyház (Hungary) : chamber furnaces, aircraft industry aluminium alloys treatment.

ČSA Praha:
aluminium alloy parts treatment, for aircraft industry The required heat processing is provided by equipment consisting of

• electric annealing car-hearth furnace
• quenching tank under the trackage in front of the furnace
• controllers and thermocouples, checking and calibrating system

The charge is placed on a charging frame connected to the furnace door, In heat-and-wet-combined processing, the charge is quickly taken in front of the furnace above the quenching tanks after the heat is completed and downed to the quenching bath through the frame bottom. The set is shifted using a drawing chain.

ZML Kety, Poland, Alusuisse Děčín, Alufinal Žiar n. Hronom (Slovakia) – mould heating.

Strojmetal Kamenice – gas - and electric heated car hearth and continuous furnaces, heat processing of parts for automobile industry, heating cut parts prior to pressing.

ALCAN Děčín – gas heated continuous furnace for tempering of aluminium profiles after pressing.

print | top of the page