Tempering is processed in specific molten metals furnaces. Heated by electricity or gas, the system is foreseen to keep a full constant processing temperature. Reliability of the system has been demonstrated on chrome vanadium and silicon manganese spring wire quality.
Our quenching technology has proven achieving the most stringent requirements and its capability to handle large ranges of diameters from 0,3 mm for carding wire up to 8 mm or even flexibly in the case of 2 parallel wire fields.
Safety is embedded in the overall design to avoid fire risks and the easy handling of the wires for the operator.
Muffled tube furnaces:
As the oil tempering process requires the full solubility of the carbide in the whole section of the wire, the product has to be brought to high temperature.
For in-line oil-quench FIB masters the technology with muffled tube furnaces heated by electricity and the technology has been applied for wire sizes from 0,23 mm (carding wire) up to 13 mm
The design takes into account the easy replacement of the tubes and of the heating elements. Special care is taken to avoid the deformation of the tubes and to assure an efficient insulation of the furnace.
As the control of the temperature profile is critical for the process, a high-tech system controls the temperature in the several zones.
Processing spring wire is a challenge: on one side the surface of the processed wires must be fully under control while in the meantime the metallurgical structure of the wires has to match with the most stringent mechanical conditions.
FIB has a long successful experience in the supply of oil tempered lines but also with upstream open fire patenting lines. Unshaved wires handled in the FIB open fire furnace IMFLEX have been successfully processed without traces of decarburization.
Regarding the oil tempering process, indirect heating is used.