Process for preparing low temperature high magnetic induction grain oriented silicon steel

Abstract

The invention discloses a process method for preparing low-temperature high-magnetic induction oriented silicon steel, and belongs to the technical field of steelmaking. The process method is different from that of a traditional nitriding technology after decarbonization and annealing of a cold-rolled sheet, nitriding is carried out in a temperature range of initial recrystallization in the initial stage of decarbonization and annealing of the cold-rolled sheet, and a stable nitride precipitation phase is formed by reducing the escape of nitrogen by controlling nitrogen content in different plate thicknesses and the formation of an inner oxide layer in the decarbonization process. The process method has the advantages that the surface layer of primary recrystallized grains subjected to nitridation and decarbonization is small, and the grain size ratio of a central layer is within a proper range, so that the number of Gaussian crystal nucleus is increased, the grain size of a finished product is reduced so as to achieve the purpose of reducing iron loss, the dual purposes of improving the iron loss of the product and ensuring stable performance are achieved, and the process method has the beneficial effects that the iron loss of the product is improved, magnetic stability is improved, and energy-saving and consumption-reducing effects are achieved.

Description

technical field [0001] The invention relates to process control of high magnetic induction oriented silicon steel, belongs to the technical field of steelmaking, and in particular relates to a process for preparing low temperature high magnetic induction oriented silicon steel. Background technique [0002] Silicon steel has excellent magnetic properties such as low loss and low magnetostriction, and is the most important magnetic material in the electric power and electronics industries. Silicon steel is usually divided into oriented silicon steel and non-oriented silicon steel. Among them, grain-oriented silicon steel utilizes secondary recrystallization to grow abnormally, so that the finished product has a preferred orientation of Gaussian texture {111}<001>. Due to the orientation characteristics of the finished grains, the <001> axis of the internal lattice is as parallel as possible to the rolling direction. This material has good magnetic permeability in...

AI Technical Summary

Problems solved by technology

[0005] With the development of low temperature and high magnetic induction grain oriented silicon steel manufacturing technology, it is found that the existing manufacturing method still has disadvantages: ① As mentioned above, nitriding is carried out after the formation of primary recrystallization, and the inhibitory effect of nitride precipitation on the primary grain is limited. It is still necessary to add alloy solute elements in the alloying process of steelmaking to provide a certain amount of innate inhibitors, which will easily increase the inclusions in the steel and affect the performance

② Nitriding is carried out after the initial recrystallization is formed. Once the initial grain size is too large during the decarburization annealing process, it is difficult to control the initial recrystallization size

Both cause nitriding efficiency and media usage to decrease at the same time

However, in actual production, due to the unstable nitride precipitation phase after low-temperature nitriding, the escape of nitrogen in the subsequent process and early nitriding will affect the initial grain, and the performance is likely to be unstable.

[0013] Japanese Patent Laid-Open No. 2-294428 adopts the method of synchronous decarburization and nitriding annealing to produce high magnetic induction oriented silicon steel. This method can improve nitriding efficiency and production efficiency, but does not consider the initial grain caused by the change of nitriding process Changes, product performance prone to instability

[0014] Therefore, although the above-mentioned improved process methods can effectively improve the nitriding efficiency, there are technical defects in the stable control of the primary grain after decarburization, so that it is impossible to improve product performance on the basis of reducing production energy consumption and improving production efficiency

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