ASTM TM8Thermal bimetal alloy strip
overview
Thermal bimetal strip is by the different expansion coefficient of two or more than two layers of metal or metal solid combination, and along the entire interface varies with temperature and the thermal function of shape changes in composite materials.One of high expansion coefficient become active layer, low expansion coefficient becomes passive.When requirements with high resistivity, but heat sensitive resistance performance is essentially the same type of thermal bimetal series, can be added between the two layers of different thickness of middle layer as a shunt layer, is to achieve the purpose of control different resistivity.
The basic characteristic of the thermal bimetal is changing with temperature and temperature deformation, resulting in a certain moment.Many devices use this feature to convert heat energy into mechanical work to achieve automatic control.Thermal bimetal used for control system and temperature sensor in the measuring instrument.
System of heat treatment: heat sensitive resistance, resistivity and elastic modulus of samples before the measurement must undergo heat treatment, to eliminate stress.
Main features: high heat sensitive properties and high resistivity, but lower elastic modulus and allowed stress, can increase the sensitivity of the instrument, smaller size and increase the reaction
shop sign |
ASTM TM8 |
With brand |
|
Composite layer
alloybrand |
High expansion layer |
Mn72Ni10Cu18 |
middle layer |
-------- |
Low expansion layer |
Ni36 |
Chemical composition
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Ni |
Cr |
Fe |
Co |
Cu |
Zn |
Mn |
Si |
C |
S |
P |
≤ |
Ni36 |
35.0~37.0 |
- |
allowance |
- |
- |
- |
≤0.6 |
≤0.3 |
0.05 |
0.02 |
0.02 |
Mn72Ni10Cu18 |
8.0~11.0 |
- |
≤0.8 |
- |
17.0~19.0 |
- |
allowance |
≤0.5 |
0.05 |
0.03 |
0.02 |
performance
Than bending K(20~135ºC) |
Temperature curvature
F/(greenhouse ~ 130 ºC) |
resistivity |
Linear temperature
/ ºC |
Allows the use of temperature / ºC |
Density (g/cm after) |
Nominal value |
Allowable deviation |
Standard values |
Allowable deviation |
Level 1 |
Level 2 |
14.5 |
±5% |
±7% |
39.0%±5% |
1.4 |
±5% |
-20~150 |
-70~200 |
7.5 |
production process
Cold rolled →go oil → pickling → annealing cold-rolled →oil → pickling → annealing cold-rolled → conform to the requirements of the use of thermal bimetal strip
Welding performance: thermal bimetal not allowed in the flame or electric arc brazing or welding.Spot welding and resistance welding can be performed.Must be removed before welding, component spot welding processing surface oxidation film, grease and other stolen goods.5 j20110 because of its high expansion layer with low melting point, surface oxidation, be especially careful when welding.