GENERAL INFORMATION

Fechral Fechroma®23H has a very high maximal working temperature (up to 1300^оС) and it is several times more durable in comparison with nichrome at operation at high temperatures (1000-1350^оС) in commonly occurring oxidizing, sulfur-containing and other environments.

The manufacturing techniques of fechral Fechroma®23H provide uniform structure, uniformity of protective oxidic layer and high adhesion of this layer to a surface. In a combination with decrease of carbon level, the high wire ductility, lack of tendency to intercrystalline high-temperature corrosion, high creep strength and also resistance against oxidation, sulfidization and carburizing at increased temperatures are guaranteed.

High resistance to oxidation and corrosion in the most widespread industrial oxidizing, sulfur-containing, etc. hostile environment, is caused by the nature of chemically inert, dense superficial protective layer on a basis Al₂O₃.

Preoxidizing of fechral wire (2 hours of holding at temperature more than 1000°C on air) provides a possibility of operation even in the recovery atmospheres. The light gray protective film of oxide of aluminum, which is formed on a surface, effectively prevents possible corrosion of metal. Properties of Fechroma®23H alloy are caused, in particular, by the fact that on the surface of alloy the high-strength film of Al₂O₃, which is the excellent insulator, is formed and it prevents corrosion more effectively in comparison with the oxide of chrome (Cr₂O₃), which is formed on the surface of nichrome. It is known that the chrome oxide film (nichromes) is less steady, exfoliates and evaporates faster, that leads to reduction of service life of the heater. Use of nichrome on limit temperatures can lead to the fact that above-mentioned products of evaporation can even pollute the heated surfaces of the working equipment and the thermoprocessed products. Thermal evaporation of nichrome in nonoxidizing and other atmospheres can cause additional thermal instability and even short circuit of the accompanying electric chains.

DELIVERY CONDITION

Fechroma®23 is delivered in shapes of wire and strip Cold-rolled wire from alloy of grade Fechroma®23H produce in soft heat-treated (HT) conditions with  diameters 0,1-10 mm according standard DIN17470.

Diameter tolerance of wire is ±0,1 mm, and wire ovality is within half of diameter tolerance limit.

Strip*

Delivery condition:

Cold-rolled oxidized with bright annealing or oxidized.

PROCESSING PROPERTIES