Chromel.
Chromel is an alloy of chromium (8,7-10%) and Nickel (89-91%), characterized by a good combination of thermoelectric properties and heat resistance.
Description:
Chromel is an alloy of chromium (Cr) (8,7-10%) and Nickel (Ni) (89-91%) with different additives of other metals: cobalt (Co) (1%), carbon (C) (0.2%), iron (Fe) (0.2%). Is characterized by good combination of thermoelectric properties and heat resistance.
Chromel is used for the manufacture of countervailing wires, rheostats, heating devices and thermocouples.
Properties:
– has a silver color,
– has a large and almost linear change in thermal electromotive force (thermal EMF) for a large interval of temperatures,
– has a high resistance to oxidation
– elongation at break of <44%,
– impact resistance of 108 j·m−1,
– modulus of elasticity 186 GPA,
– tensile strength 620-780 MPa,
– 8 density 710 kg/m3,
– melting point of 1420 °C,
– paramagnetic,
– the coefficient of thermal expansion of 15.7×10-6 K−1 at 800 °C,
– the thermal conductivity of 17.6 W·m−1·K−1 at 20 °C, to 34.3 W·m−1·K−1 at 800 °C,
– heat resistant, maximum working temperature in air is 1100 °C,
– temperature coefficient of linear expansion of 13.1·10-6 K−1 (0-100 °C),
– electrical resistivity of 6.8·10-7 Ω·m.