Manufacturing method of oriented silicon steel sheets for low-noise transformer

Abstract

The invention discloses a manufacturing method of oriented silicon steel sheets for a low-noise transformer. Grooves in special shaped are formed in a single side or double sides of silicon steel sheets in a mark carving method; the bottom surfaces of the grooves are parallel to approximately parallel to the surfaces of the silicon steel sheets; the angle with the maximum absolute value in included angles between the single side or multiple sides of the inner walls of the groove and the normal plane is defined to be the included angle theta; the include angle theta is in a range of being greater than or equal to -60 degrees but smaller than 0 degree; the included angle theta of each side edge is identical or different; the normal plane refers to a plane vertical to the rolling direction of the silicon steel sheets. The mark carving processing mode is set before or after the decarburizing annealing, or is after the high-temperature annealing, or is after the insulation coating flattening annealing. Pulse laser beams with the single-pulse instantaneous peak value power density not lower than 2.0*10<6>W / mm<2> are used for processing on the surface of the silicon sheets; the laser injection total energy is between 0.002J / mm to 1.3J / mm. The oriented silicon steel sheets manufactured by the method have the advantages that the iron loss is low; after the stress relief annealing, the performance is not reduced; in addition, under the same manufacturing and test conditions, the noise level of the transformer is lowered.

Description

technical field [0001] The invention relates to a method for manufacturing an oriented silicon steel sheet for a low-noise transformer, in particular to a method for manufacturing a notched oriented silicon steel sheet for a low-loss, low-noise transformer. Background technique [0002] In recent years, global energy and environmental problems have become increasingly prominent, and the demand for energy saving and consumption reduction has continued to increase. At present, the loss of the transformer accounts for about 40% of the power transmission system, and the loss of the core made of oriented silicon steel accounts for about 20% of the total loss. Core loss is often referred to simply as iron loss. It can be seen that reducing the iron loss of grain-oriented silicon steel has huge economic and social benefits. In addition, transformer noise caused by factors such as magnetostriction of silicon steel sheets and magnetic force line distortion has also attracted much a...

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Problems solved by technology

However, since the magnetic permeability of the groove is much smaller than that of the substrate, magnetic flux leakage will be formed there during the magnetization process, and the existence of free magnetic poles makes the magnetic force line always perpendicular to the side wall of the groove. At this time, the magnetic force line warps, such as figure 1 shown

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