Amorphous alloy has reached the highest limit of magnetic induction intensity, the coercive force is small, high damage inferior strengths, so to the effects of high efficiency, energy saving, environmental protection is widely used in power transformer.
Early in 2009 on the industry market in China, however, amorphous strips of amorphous alloy transformer used almost all is produced by Japan Hitachi metals enterprise.
Peace of 2010, China's science and technology enterprises with independent intellectual property rights - amorphous alloy strip yield in production line construction, break through the amorphous doesn't rely on imports of raw materials situation, speed up the progress of low carbon economy of the electric power industry in China.
So far the amorphous alloy iron core sees fit and use the approximate rectangle lap type winding structure, forming the core of external stress is very big, the magnetic properties of the special was serious damage, make sure after heat treatment of annealing ability to diminish the stress.
Matters and heat treatment of annealing the silicon alloy core in the whole manufacturing process of most key is also the most difficult to curb the process.
Domestic amorphous alloy strip transverse is an arc, the external stress is larger than import strip, plus composition, temperature at the time of the heat treatment, sharpness is more better, because of this, formulate appropriate heat treatment of annealing process, the end of the amorphous alloy strip on domestic iron temperament and quality is shut.
A, heat treatment of annealing temperature.
Fitting for the core of the annealing temperature, not only to guarantee the external stress alleviation core, reducing its special magnetic properties, and to be able to do our best to reduce the brittleness of amorphous alloy strip, detract from the risk of breakage in the core processing.
Try to show that domestic final annealing temperature of amorphous alloy strip core stem in 375 ~ 380 ℃ is the best.
Second, the heat treatment of heat preservation time.
Experiments show that the unit excitation power with annealing time decreases, while the core unit of no-load damage increases with annealing time, strip and core of brittleness, and with the increase of annealing time.
Because of this, must be based on user demand for iron character can, choose the best time to keep warm.
3, heat treatment of trying our best to take care of atmosphere.
Core in the high temperature heat treatment of annealing in oxygen is easy to change.
Appearance is core after the oxygen, despite rusty appearance, more important is can cause core light damage apparent increase.
Because of this, the core in the whole heat treatment of annealing process is important to consider appropriate and use the atmosphere to take care of.
Up to now the commonly used technology trying to care for nitrogen or argon gas.
Four, soft temperature reductions.
Because core when batch production is a multiple loading, batch heat treatment, so the reasonable level of soft slow temperature, not only affect the performance of the amorphous alloy iron core end result, and also affect the yield rate and production capital.
Ordinary, the faster the speed of temperature rise, separated sex is bigger.
Amorphous alloy strip, however, the experimental results show that domestic core in the high temperature and close to the temperature at which the best annealing temperature point lost less, almost can stifle within 3 ℃.
So the temperature stage, domestic core of amorphous alloy strip can be directly heated up fast.
In addition to reduce temperature speed, to reduce the no-load damage of core is good, but with special circumstances increases the excitation power of the core.
So, the best temperature lowering speed demand experience value to make the best choose.
Five, plus a magnetic field.
After forming of amorphous alloy iron core, attached with dc magnetic field when annealing obtain satisfactory magnetic domain orientation, as to improve the magnetic properties of the special.
Try to show that domestic core of amorphous alloy strip annealing of field strength should be about 2000 a/m or magnetic field current volume in 1400 a can guarantee when annealing core materials reached the highest limit, such ability to achieve the best effect of annealing.