METHOD OF PROCESSING OF LAMINATED CORE OF CORE-TYPE TRANSFORMER Russian patent published in 2015 - IPC H01F41/02 C21D8/12 

FIELD: electricity.

SUBSTANCE: when processing the laminated core of the core-type transformer, containing yokes and cores assembled from separate layers of ferromagnetic rectangular narrow and wide plates its rectangular and U-shaped plates are cut out from the rolled tape along the direction of its rolling, it is annealed at 700-800°C within 60-20 minutes, slowly cooled down to 20°C and across the rolling direction the zones of local laser impact are applied along the whole length of plates, for the steel with coarse grain 15-50 mm with the interval 5-2 mm, and with fine grain 5-15 mm - 15-5 mm. In the places of joints of separate plates of yokes and cores the laser impact is performed step-by-step, forming the angular front at the angle 45 degrees to the direction of rolling of plates. On the yokes of U-shaped part of the core the zones of local laser impact are applied along the direction of rolling. Then the package of closed core is formed, the ends of plates are stacked end-to-end to each other at the angle 90 degrees in each layer and in the subsequent layer with overlapping of the previous layer, lapping joints between plates.

EFFECT: decrease of magnetic losses.

2 cl, 1 dwg, 1 tbl