Nichrome Cr20Ni30

Fabrication method of cold drawn wire Cr20Ni30, provide similar structure, uniformity of protective oxide layer and high adhesion of this layer to the surface. With carbon reduction to ≤0.03% guarantee high plasticity of the wire, high creep strength, and also oxide resistance, sulfidization and carbonization at high temperatures.

Fields of applications:

Higher specific electric resistance Cr20Ni30 in comparison with Cr20Ni80 and also less specific weight let economize in correlation "ohmic resistance/value, kg".

Used in high temperature electric furnaces, firing furnaces and fire drying furnaces, different electric heaters, creep resistance, ductility, (including after long exploitation), stability of the form and increased term of exploitation.

Technical information.

Cold drawn wire is produced from the alloy Cr20Ni30 grade is produced in soft heat-treated position diameter 0.1- 10 mm according to the standard DIN 17470.

Limiting deflections in diameter of the wire not exceed ±0.100 mm, and the ovality of the wire is not more than half of the field tolerance in diameter.

Chemical composition of Cr20Ni30 and typical mechanical and physical properties are in the table:

Chemical composition, % :
С	< 0,05
Cr	19,5 - 21,5
Ni	30 - 31
Si	1,8-3,0
Mn	max 1,0
Al	max 0,3
S	max 0,3
S	< 0,005
P	< 0,02
Fe	basis

Chemical composition, % :
Breaking point, МPa	560-680
Yield Strength, МPa	250-350
Elongation, %	25-35
Density, g/сm3	7,9
Hardness, Hv	180
Melting temperature	1390 °С
Specific electric resistance Оm/mm2/m at 20°C	1,04
Transmissibility in conditions absolute oxidation	0,88

Durability of the alloy, tested the method G, at temperature 1150 °C, composes not less 120 hours.

Advantages:

• Not high density – 7.9 g/сm3 against 8.4 g/сm3 for Cr20Ni80, that let economize to 6% on the weight;


• Temperature of exploitation and corrosion resistance in the air, vacuum, oxide, carbon and nitrogen-containing mediums, argon, ammonia, in the humid air not worse than more expensive grade Cr20Ni80;


• Excellent resistance in restorative and sulphur content mediums (in comparison with nichrome Cr20Ni80 and Cr15Ni60).