The technical key of heat-treatment of domestic am

发表时间：2017-05-26

Amorphous alloy with high saturation magnetic induction intensity, the coercive force is small, and low loss, so the effect with high efficiency, energy saving, environmental protection is widely used in power transformer. However, before 2009, almost all of the amorphous materials used for amorphous alloys in our entire industry market were produced by Hitachi metals of Japan. In 2010, antai technology company with independent intellectual property rights in China - amorphous alloy strip production line construction, broke the passive situation of amorphous dependent on imports of raw materials, speeds up the low carbon economy development of the electric power industry in our country.

The amorphous alloy iron core adopts the lap of the approximate rectangle type winding structure, forming the core of internal stress is very large, magnetic properties were severely damaged, must be eliminated by annealing heat treatment to the stress. Heat treatment annealing process is the most critical and most difficult procedure in the whole production process of amorphous alloy. Domestic amorphous alloy strip transverse an arc, the internal stress is larger than import strip, plus the composition of different, more sensitive to heat treatment temperature, therefore, make appropriate annealing heat treatment process, amorphous alloy strip on domestic final core is very important to the quality and performance.

Heat annealing temperature. Appropriate annealing temperature of the core, to ensure that not only eliminate the internal stress of core, restore its magnetic properties, and to be able to reduce the brittleness of amorphous alloy strip, as far as possible to reduce the risk of breakage in the core processing. Amorphous alloy strip test shows that domestic core final annealing temperature control in 375 ~ 380 ℃ is the best.

Second, heat treatment insulation time. Experiments show that the unit excitation power with the annealing time is reduced, and the core unit of no-load loss increases with annealing time, and the core of strip brittleness, and increases with the increase of annealing time. Therefore, the optimum heat preservation time must be chosen according to the user's requirement of the core performance.

3, heat treatment protection atmosphere. Iron core is easily oxidized when annealed from heat treatment. After the surface of the iron core is oxidized, besides the surface of the rust, more important is the loss of the iron core. Therefore, the iron core must adopt the atmosphere protection during the whole annealing process. The currently used process gas is nitrogen or argon gas.

Temperature increase and temperature drop. Because of the core are multiple loading, when mass production batch heat treatment, so the reasonable heating and cooling speed, not only affects the performance of the amorphous alloy iron core as a result, but also affect the production efficiency and production cost. In general, the faster the temperature, the greater the dispersion. However, the experimental results show that domestic amorphous alloy strip core arrive in high temperature and close to the optimum annealing temperature point of discrete small, almost can be controlled within 3 ℃. Therefore, in the heating phase, the domestic amorphous alloy strip iron core can be directly heated up directly. In addition, it is beneficial to reduce the empty load dissipation of the core, but also increase the excitation power of the core. Therefore, the optimal cooling speed requires the accumulation of empirical data to make the best choice.

Five, plus the magnetic field. After the forming of amorphous alloy core, the magnetic properties of the magnetic domain are obtained by attaching the dc magnetic field to the annealing. Annealing amorphous alloy strip test showed that domestic core of field strength should be around 2000 a/m current or magnetic field when in 1400 a, can guarantee to annealing when saturated core material, so as to achieve the best annealing effect.