Ni22Cr3-Ni36 Bimetallic Alloy
Introduction
Ni22Cr3-Ni36 bimetallic alloy is formed by two or more layers of alloys or metals with different expansion coefficient which are firmly combined together along the entire contact surface. As a thermosensitive composite material, its shape varies with the temperature. The layer with higher expansion coefficient is called active layer, and the other is called passive layer. When a series of resistance bimetallic alloy with different resistivity bust almost the same thermal sensitivity are required, a intermediate layer of different thicknesses can be added between the two layers as a distributary layer to control different resistivity.
The basic property of this bimetallic alloy is its bending out of shape with the temperature changes to produce a certain torque. Many devices uses this property to convert the thermal energy to mechanical work for realizing automatic control. The bimetal is used as thermosensitive element in control system and measuring instrument.
Supply of Ni22Cr3-Ni36 bimetallic alloy| Style | Size | ||
| Strip | W= 5~120mm | T= 0.1mm | |
This chart of the bimetallic strip shows how the thermal expansion difference between the two metals results in a larger lateral displacement of the strip.
Application
Ni22Cr3-Ni36 bimetallic material is mainly used in automatic control equipment and instrument (like exhaust temperature gage, thermostat, pressurizer, temperature relay, automatic protection switching, diaphragm meter) as thermosensitive element like temperature control, temperature compensation, current limiting, temperature indicator, etc.
Composition
High expansion layer: Ni22Cr3
Low expansion layer: Ni36
| Grade | C | Si | Mn | P | S | Ni | Cr | Cu | Fe |
| Ni36 | ≤0.05 | ≤0.3 | ≤0.6 | ≤0.02 | ≤0.02 | 35~37 | - | - | Bal. |
| Ni22Cr3 | ≤0.35 | 0.15~0.3 | 0.3~0.6 | ≤0.02 | ≤0.02 | 21~23 | 2.0~4.0 | - | Bal. |
| Density (g/cm3) | 8.2 |
| Resistivity under 20℃(Ωmm2/m) | 0.8±5% |
| Thermal conductivity, λ/ W/(m*℃) | 22 |
| Elasticity modulus, E/ Gpa | 147~177 |
| Specific curvature, K / 10-6℃-1 (20~135℃) | 14.3 |
| Flexivity, F/ (20~130℃) 10-6℃-1 | 26.2%±5% |
| Allowable operating temperature (℃) | -70~ 350 |
| Linear temperature (℃) | -20~ 180 |
Index
nickel chromium alloy, heat sensitive material, alloy strip
