Non-oriented silicon steel for rotor and production method thereof

Abstract

The invention discloses a non-oriented silicon steel for a rotor and a production method thereof. The steel consists of the following components in percentage by weight: 0.001-0.004% of C, 2.5-4.0% of Si, 0.5-1.5% of Al, 0.10-1.50% of Mn, not more than 0.02% of P, not more than 0.001% of S, not less than 4.1% and not more than 6.0% of Si+Al/2+Mn, not more than 0.002% of N, not more than 0.005% of B and the balance of Fe and inevitable impurities. The production method mainly comprises the following steps of: refining process, namely sequentially deoxidizing Si and Al, and finally, adding CaSi alloy for Ca treatment; heating a casting blank in a heating furnace to be 1100 DEG C, insulating and then rolling; normalizing, carrying out acid cleaning and cold rolling, wherein the reduction rate is 70-78%; and tensioning and annealing a belt, wherein the temperature is 920-980 DEG C, and the tension is controlled between 0.5MPa and 1.5MPa. By utilizing the method, electrical sheets with excellent electromagnetic property, yield strength and fatigue performance can be obtained, the annealing temperature is reduced, the production energy consumption can be decreased, and furthermore, the production cost is lowered.

Description

technical field [0001] The invention relates to a non-oriented electrical steel manufacturing technology, in particular to a non-oriented silicon steel for a rotor and a manufacturing method thereof. Background technique [0002] High-grade non-oriented silicon steel is mainly used to manufacture stator 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. [0003] However, the materials used to manufacture large generators and motor rotors must withstand centrifugal force during rotation and be able to w...

AI Technical Summary

Problems solved by technology

For example, in ensuring the magnetic properties (B50≥1.64T, P 15 / 50 ≤2.70W / kg, anisotropy≤9%), the yield strength can reach over 420MPa, and the low-cycle fatigue strength can reach over 420MPa, which is often not met by ordinary high-grade non-oriented silicon steel

[0004] U.S. Patent US20090202383 proposes that by adding Cu, Ni, Cr, Mo, W and other elements, the solid solution strengthening of the matrix and the precipitation strengthening of the second phase are carried out, and the effect of improving the yield strength is remarkable. However, this method has low magnetic induction and high cost. and does not take fatigue into account

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