Production method of high magnetic induction oriented silicon steel

Abstract

The invention discloses a production method of high magnetic induction oriented silicon steel, comprising the following steps: a) carrying out steel-making and continuous casting to produce slabs, wherein the slabs comprise 0.05-0.10 wt% of C, 2.5-4.0 wt% of Si, 0.008-0.028 wt% of S, 0.008-0.040 wt% of Als, 0.004-0.012 wt% of N, 0.08-0.20 wt% of Mn, 0.08-0.30 wt% of Cu, and the balance of Fe; b) preserving heat at no higher than 1250 DEG C and then carrying out hot rolling, wherein the finishing temperature is higher than 850 DEG C; c) carrying out annealing, pickling, once cold rolling or twice cold rolling containing intermediate annealing to get finished product thickness; d) decarburizing annealing, and preserving heat in wet nitrogen-hydrogen protective atmosphere; e) coating an annealing isolation agent and then carrying out high temperature annealing; f) carrying out nitriding treatment; and g) coating an insulating coating, and carrying out stretching, flattening and annealing. According to the invention, the types and distribution of the inhibitor is adjusted, the stable and high inhibition capability is guaranteed, by cooperating with hot rolling and twice recrystallization, the high magnetic induction oriented silicon steel with stable properties is obtained.

Description

technical field [0001] The invention relates to a production method of high magnetic induction oriented silicon steel, which is characterized in that under the relatively low slab heating temperature and the correspondingly adjusted hot rolling system, the inhibitors are fully separated out and have a suitable form distribution, and through decarburization The strict control of the average grain size of the primary recrystallization of the steel plate after annealing, as well as the conventional control of the production conditions of other post-processes such as hot-rolled plate annealing and cold rolling, can obtain perfect secondary recrystallization and improve the electromagnetic properties of oriented silicon steel products. Background technique [0002] Oriented silicon steel users focus on the magnetic properties of products, mainly including magnetic induction and iron loss. Generally, oriented silicon steel with a magnetic induction value (B8) higher than or equal t...

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Problems solved by technology

More post-process influencing factors will lead to increased control difficulty, increased chances of instability such as insufficient inhibitor concentration or early decomposition, resulting in imperfect secondary recrystallization and fluctuations in magnetic properties; the latter is based on AlN+ Cu compound is used as an inhibitor technology. Its production process adopts a complete decarburization annealing in the middle of two cold rollings. There is no post-process nitriding step, but its decarburization efficiency and bottom layer formation have inherent defects in the process mechanism, so Affects productivity and product performance

[0006] Although the two low-temperature technologies mentioned in Japanese Patent JP6-86631 and European Patent EP0709470 overcome the problem of high-temperature slab heating, since the former uses acquired inhibitors, the stability of inhibitors is affected by many factors of production conditions. The latter has inherent decarbonization efficiency and underlying problems, and there is a lot of room for further optimization.

Both technologies use AlN as the main inhibitor respectively, but they also found that it is difficult to obtain perfect secondary recrystallization only by the inhibitory effect of AlN. Japanese patent JP6-86631 proposes the concept that adding a small amount of B is beneficial to the improvement of magnetic properties , the European patent EP0709470 proposes to add an appropriate amount of Cu to the slab composition to obtain grain-oriented silicon steel products with stable magnetic properties

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