Non-oriented electrical steel produced by sheet continuous casting and rolling and method thereof

Abstract

The invention relates to non-oriented electrical steel produced by sheet continuous casting and rolling and a method thereof. The steel contains the following components by in percentage of by weight: 0.0031%-0.01% of C, 1.0-1.7% of Si, 1.0-2.4% of Si+2Al, at mostnot less than 0.5% of Al, 0.5-1.5% of Mn, not less thanat most 0.10% of P, not less thanat most 0.008% of S, not less thanat most 0.005% of N, not less thanat most 0.008% of Ti, and not less thanat most 0.010% of Ca, wherein Si+2Al is 1.0-2.4%. The method comprises the following steps of: smelting and treating by in vacuum; continuously casting, and controlling the thickness of a casting blank to be thickness within 50-90mm; soaking, controlling the temperature of the casting blank to be 850-950 DEG C before entering the furnace; finish rolling; coiling at the temperature of 690-780 DEG C; prickling; cold rolling; decarburizing, and controlling at the temperature to of 800-920 DEG C; and coating or not coating as required by users. The invention has no need of additionally arranging equipment and the normalizing and secondary cold rolling of hot rolled plates, the magnetism of the steel plate is good, and the corrugated defect is not found in test.

Description

technical field [0001] The invention relates to a non-oriented electrical steel and a production method thereof, in particular to non-oriented electrical steel produced by continuous casting and rolling of thin plates and a method thereof. Background technique [0002] The production process of thin slab continuous casting and rolling is short, the casting billet is thin, and the heat loss in the process is small, which can save a lot of energy and reduce costs. In addition, thin slab continuous casting and rolling can realize high-temperature final rolling and high-temperature coiling, which are difficult to achieve in traditional processes, and produce non-oriented electrical steel with excellent magnetic properties. [0003] The non-oriented electrical steel slab produced by thin slab continuous casting and rolling is thin, with fast casting speed and well-developed columnar crystals. In addition, compared with the traditional process, the production of non-oriented elec...

AI Technical Summary

Problems solved by technology

[0005] 1. Increase the carbon content in the molten steel to expand the γ phase region and the α+γ two-phase region. If C≥[(Si+Al)-0.75]% / 100, the billet undergoes phase transformation during hot rolling, making the coarse Columnar grain refinement, the disadvantage is that deep decarburization is required in the recrystallization process of the finished product, which affects the running speed of the steel strip

However, the continuous casting and rolling of thin slabs cannot completely eliminate the coarse columnar grains through phase transformation without the rough rolling process. This method alone cannot completely avoid corrugated defects.

[0006] 2. Add electromagnetic stirring equipment to increase the equiaxed grain ratio of the slab. This method is difficult to achieve in the thin slab continuous casting and rolling process

[0007] 3. Normalization (hot-rolled sheet annealing) and secondary cold rolling, this measure can reduce corrugated defects, but increases the cost, and cannot reflect the cost advantage of thin slab continuous casting and rolling to produce non-oriented electrical steel

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