Grain-oriented electrical steel sheet and manufacturing method therefor

Abstract

Disclosed is a grain-oriented electrical steel sheet comprising, by weight %: 2.0 to 6.0% of Si, 0.005% or less (0% exclusive) of C, 0.001 to 0.05% of N, 0.005 to 0.1% of Co, and the balance of Fe andinevitable impurities.

Description

technical field [0001] The present invention relates to oriented electrical steel sheet and its manufacturing method. More specifically, the present invention relates to a grain-oriented electrical steel sheet having low iron loss and excellent magnetic flux density and a method for manufacturing the same. Background technique [0002] Grain-oriented electrical steel sheet is a kind of soft magnetic material. The texture of the steel sheet relative to the rolling direction is {110}<001> Goss texture (Goss texture), so it has excellent magnetic properties in one direction or rolling direction. In order to express this Goss texture, it is necessary to carry out component control in the steelmaking step, slab reheating in hot rolling and control of hot rolling process factors, hot rolled sheet annealing heat treatment, primary recrystallization annealing and Complex processes such as secondary recrystallization annealing, and these processes should be managed very precis...

AI Technical Summary

Problems solved by technology

The method is composed of slab high-temperature heating, hot rolling, hot-rolled plate annealing, primary cold rolling, intermediate annealing, secondary cold rolling, decarburization annealing, and final annealing. The advantage of high magnetic flux density can be obtained, but it also has the disadvantage that the steel material becomes too hard to be cold-rolled once, so two cold-rolling processes with intermediate annealing must be performed, which increases the manufacturing cost

However, this method has the disadvantage that the annealing temperature of the hot-rolled sheet should be strictly controlled according to the very strict standards for manufacturing a thin grain-oriented electrical steel sheet with low iron loss and high magnetic flux density, that is, according to the contents of acid-soluble Al and nitrogen. Not only does the annealing process of the hot-rolled sheet become complicated, but also due to Cr with a strong oxygen affinity, the oxide layer formed in the decarburization and nitriding annealing process becomes quite dense, so that it is not easy to decarburize and the nitriding is not very smooth

Images