1J87 standard (GB T14987-94) high resistivity and high permeability soft magnetic alloy.
The advantages of 1J87 soft magnetic alloy alloy are not only strong mechanical properties and corrosion resistance, but also good cutting performance and welding performance. This makes 1J87 precision alloy have a great advantage in the field of manufacturing. In addition, the alloy has a small coefficient of thermal expansion and good thermal stability, allowing it to maintain a stable size and shape at high temperatures.
1J87 Chemical Composition:
c:≤0.03
p:≤0.020
s:≤0.020
mn：0.30~0.60
si：≤0.3
ni：78.5~80.5
mo：1.60~2.20
nb：6.50~7.50
fe: margin.
Heat treatment: Process annealing: In order to eliminate all strains and restore the alloy to a soft state suitable for further cold rolling or drawing, forming, bending or similar operations, annealing at 1020 1080 for no more than 1 hour. Since high-nickel and high-permeability alloys are easy to absorb pollutants such as carbon, sulfur, and oxygen from the combustion furnace gas, intermediate annealing should be carried out in an atmosphere of free ammonia, hydrogen, vacuum or inert gas.
Final annealing: In order to obtain maximum softness and the best magnetoelectric properties, the cold-deformed 1J87 alloy should be annealed at 1150 for 3 5 hours in an oxygen-free dry hydrogen atmosphere below -40, with a cooling of 200 per hour.
Oil, grease, paint, and all other contaminants must be removed before annealing. When hydrogen is annealed, the parts are separated by inert insulating powders (e.g., magnesium oxide, alumina).
Vacuum heat treatment can be used, but it often results in a sacrifice of magnetic properties compared to heat treatment in a dry hydrogen atmosphere.
Main features - examples of use:
The 1J87 soft magnetic alloy with high hardness, high resistance and high permeability has high initial permeability, high hardness, high resistivity, magnetic stress insensitivity and good wear resistance. It is used to manufacture the heads and chips of various tape recorders and the cores of high-frequency devices.