The page contains the alloy description: physical and mechanical properties, applications, grades, types of products.
Main information
High-resistant precision alloys - materials with high resistance and set temperature coefficient of resistance; they are applied as heaters of electric furnaces, resistive elements and resistance thermometers.
Precision alloys with high resistance are usually divided into groups according to their intended use. These are materials for heaters or resistive elements.
Heat-resistant in the following atmospheres: oxidizing, containing sulphur and sulphides, carbon-containing medium, hydrogen, vacuum. They are operated when contacting high-aluminous ceramics with low iron oxide content. They can creep under high temperatures
Electric heaters of furnaces, household appliances and thermal effect equipment. Current leads
For Ni-Cr based heaters
NiCr 60 15-A NiCr 80 20-A
Heat-resistant in an oxidizing atmosphere, nitrogen, ammonia. Unstable in sulphur- and sulphide-containing atmosphere. More heatproof if compared with Fe-Cr-Al based materials
Electric heaters of furnaces and household appliances
CrNi70Al CrNi60AlЗ Cr15Ni60AlЗA
Heat-resistant in an oxidizing atmosphere, vacuum, hydrogen. More heatproof if compared with Fe-Cr-Al based materials
Electric heaters of furnaces. Hooks for hanging heaters
CrNi20AlSI (EKI)
Heat-resistant in an oxidizing atmosphere. More heatproof if compared with Fe-Cr-Al based materials
Electric heaters of furnaces, household appliances and thermal effect equipment. Current leads for Ni-Cr heaters
Materials for resistors
EP277-VI
Extreme working temperatures: 20-300 °С
For small resistive elements
Ni63MnCr with Ga
(-70)-200 °С
Ni80CrAlCu-VI
(-70)-350 °С
NiMo10CrSi
(-269)-300 °С
Cr20Ni75Al-VI
(-70)-350 °С
For precision printed resistors
NiMo23CrAl-IB
(-196)-540 °С
For precision wire and printed resistors
NiMo20AlV with Ge
(-269)-500 °С
For ultra-precise resistive elements, low and high temperature resistive strain sensors
Cr20Ni73AlMo-VI
(-196)-400 °С
For high-temperature resistive strain sensors and precision printed resistive elements
NiMo10CrAl with Ge
(-196)-450 °С
For high- and low-temperature resistive strain sensors and precision printed resistive elements
NiMo23AlV-VI
(-269)-500 °С
Cr13Al5VMo-VI
(-269)-400 °С
For high- and low-temperature resistive elements and resistive strain sensors
NiMo23CrAl-VI
(-269)-400 °С
For high-temperature resistive strain sensors
Cr21Al5VMo-VI
(-196)-600 °С
Properties
The most useful materials with high resistance also depend on the application. Thus, temperature coefficient of resistance is the main value for resistive elements. Its range is 10-6-10-3 K-1 depending on the alloy application - for precision resistors and resistive strain sensors; for general-purpose resistive elements; for thermal resistors and resistance thermometers.
First of all, heater alloys should have a high resistance and provide minimally possible fluctuations along the heater.
Also the considered materials should have temporally stable electrical properties, linear dependancy of the resistance on temperature, good plasticity, high threshold working temperature and long service life.
Grades
The main grades of precision alloys with high resistance are given in Classification section, Table 1. The chemical composition and other requirements are regulated by GOST 10994-74.
Applications
These alloys have two main applications: production of heating elements and resistors.
Precision materials are made for making electric heaters of furnaces, household appliances and thermal effect equipment. Also they are used for making auxiliary parts (e.g., current leads and hooks for fastening heaters in furnaces).
These alloys are made of the following resistance elements:
small;
precision printed;
precision wire;
ultra-precise;
low- and high-temperature resistive strain sensors;
resistance thermometers;
thermal resistors.
Products
High-resistant materials are produced in form of strips, flattened strips, flat bars, wire and rods. The application and use conditions determine the blank use.
