Introduction
1J79 has excellent magnetic properties. It is a commonly used iron-nickel alloy (soft magnetic alloy), also known as a high magnetic permeability alloy. It mainly achieves sufficient magnetic permeability and magnetic saturation induction strength through a reasonable combination of nickel and iron. In 1J79, the addition of molybdenum and copper elements has increased the resistivity of the material and reduced the eddy current loss after the iron core is made. At the same time, the added elements can also increase the hardness of the material, which is particularly beneficial for wear in applications such as magnetic heads. The production process of 1J79 alloy is complex. For example, the rolling process, annealing temperature, the time after annealing, the cooling speed, etc. all have a great impact on the final magnetic properties of the material. At present, the company has mature production processes. 1J79 products are often used in iron cores of medium and high-frequency transformers or devices with strict sensitivity requirements.
Chemical composition
| Brand number | Chemical composition (mass fraction)% |
| 1J79 | C | P | S | Mn | Si | Ni | Cr | Co | Mo | Cu | Fe |
| ≤0.03 | ≤0.02 | ≤0.02 | 0.6-1.1 | 0.3-0.5 | 78.5-80 | - | - | 3.8-4.1 | ≤0.20 | margin |
Mechanical properties
| Resistivity μΩ·m | Density g/cm3 | Curie point ℃ | Saturated magnetostrictive coefficient | Brinell hardness HBS | Tensile strength MPa | Yield Strength MPa | Elongation % |
| 0.55 | 8.6 | 450 | 2 | Cold and hard | Soft | Cold and hard | Soft | Cold and hard | Soft | Cold and hard | Soft |
| 210 | 120 | 1030 | 560 | 980 | 150 | 3 | 50 |
Average coefficient of expansion
| Linear expansion coefficient within the following temperature range /(x10-6/℃) |
| 20-100℃ | 20-200℃ | 20-300℃ | 20-400℃ | 20-500℃ | 20-600℃ | 20-700℃ | 20-800℃ | 20-900℃ |
| 10.3-10.8 | 10.9-11.2 | 11.4-12.9 | 11.9-12.5 | 12.3-13.2 | 12.7-13.4 | 13.4-13.6 | 13.4-13.6 | 13.2-13.7 |
Application areas
It has high initial magnetic permeability, various transformers, transformers, magnetic amplifiers, choke iron and magnetic shields that work in weak magnetic work.