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Detailed Selling Lead DescriptionBrand: lanzhu
Model: 板材、棒材、带材、半成品，成品
Min. Order: 10
Invar is an iron-nickel austenitic alloy of lowest thermal expansivity. It is strong, tough, ductile and possesses a useful
degree of corrosion resistance, it is magnetic at temperatures below its Curie point and non-magnetic at temperatures above. Invar is
therefore always magnetic in the temperature range in which it exhibits the low expansion characteristics. Invar is the standard alloy
for low expansivity up to 400 oF. For applications at higher temperatures, the higher nickel alloys are recommended.
The effect of heat treatment upon the expansion of the alloy is dependent upon the method of cooling. Rapid cooling
(quenching) decreases the rate of expansion while the reverse is true when slow cooling is employed. Cold working is even more
effective than quenching in lowering the expansivity. Subsequent annealing will remove the lowering of the coefficients induced by
cold work in proportion to the temperatures employed, the alloy assuming the values corresponding to the annealed condition when a
temperature of about 1100 oF is reached. Invar which has been subjected to cold working or machining may require a stress-relieving
heat treatment for stabilization if the material is to be used for high precision work. This material is never used above its thermal
inflection point.
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