Preparation method of high-silicon non-oriented electrical steel for motor

Abstract

The invention discloses a preparation method of high-silicon non-oriented electrical steel for motors; Sn, Cu, B, Bi elements are added into electrical steel, and the contents are controlled reasonably, which bring into play the functions of each element and generate synergistic effect; wherein Sn and Cu facilitate the control of the morphology and distribution of precipitates and thus influence the texture; the added B and Bi elements can greatly reduce the annealing temperature of the electrical steel with high silicon content; only an annealing temperature of 870-890 DEG C is required to obtain magnetic performance with magnetic induction intensity B50 of more than 1.7 T, and iron loss P1.5 of less than 2.7 W / kg; with the combined action of the four elements and other routine alloying elements, the microstructure of the electrical steel is improved, and thus the mechanical properties of the steel are improved. Because the annealing temperature is decreased, furnace roller nodulation is completely avoided, and the scratch of strip steel is completely avoided; the production energy consumption is reduced, and thus the production cost is reduced.

Description

technical field [0001] The invention relates to the field of electrical steel for motors, in particular to a method for preparing high-silicon non-oriented electrical steel for motors. Background technique [0002] High-grade non-oriented silicon steel is mainly used to manufacture iron cores of large motors and generators, and its main magnetic feature is extremely low iron loss. Traditionally, its manufacturing feature is that the silicon content is more than 2.5%, and more than 0.2% aluminum is added to increase the resistance in the steel, thereby reducing the iron loss. Then implement hot rolling, normalization and cold rolling processes, and carry out final annealing and coating insulation layer. In order to reduce iron loss, the final annealing temperature is required to be above 1000°C, even 1075°C. However, the problems brought about by high temperature annealing are high cost, and the second is that the oxide attached to the surface of the strip is reduced to iro...

AI Technical Summary

Problems solved by technology

However, the problems brought about by high-temperature annealing are high cost, and the second is that the oxides attached to the surface of the strip are reduced to iron by hydrogen and accumulate on the surface of the furnace roll, thus causing nodulation of the furnace roll

However, it has been verified by experiments that when the silicon steel is annealed at 900°C, the hearth roll nodules can indeed be reduced, but its magnetic properties cannot be guaranteed, and it must be annealed above 970°C. It can be seen that it has made certain progress, making annealing The temperature has decreased to a certain extent, but at this time the nodules on the bottom of the furnace tend to increase again. Therefore, this patent is not thorough in solving this technical problem