Method for producing oriented silicon steel with good bottom by low-temperature heating

Abstract

The invention supplies a method used to produce orientation silicon steel by low temperature heating. It includes the following steps: heating the plate blank under 1280 degree centigrade; hot rolling; once or double cold rolling to gain finished product sheet thickness; nitriding treatment; decarburizing annealing; coating insulator; high temperature annealing. In the nitriding technology, heating area dew point is controlled at -15-40 degree centigrade. The invention has the advantages of high nitriding efficiency, no influence from the surface oxide film, excellent MgO coat formula which makes the magnesium silicate substrate have good magnetic property, ensure the implementation for the next hot leveling annealing and insulating coating.

Description

technical field [0001] The invention relates to a method for producing oriented silicon steel by low-temperature heating, in particular to a method for producing oriented silicon steel by low-temperature heating with a good bottom layer. Background technique [0002] (1) The production method of traditional grain-oriented silicon steel is as follows: [0003] The basic chemical composition is Si(2.5~4.5%), [C](0.01~0.10%), Mn(0.03~0.1%), S(0.012~0.050%), Als(0.01~0.05%), N(30~ 120ppm), some composition systems also contain one or more of Cu, Mo, Sb, Cr, B, Bi and other elements, and the rest are iron and unavoidable impurity elements; the slab is heated in a special high-temperature heating furnace to The temperature is about 1400 ℃, and the heat preservation is carried out for more than 30 minutes to fully dissolve the inclusions. After the hot-rolled sheet is normalized, it is pickled; it is rolled to the finished product by one cold rolling or two or more cold rolling me...

AI Technical Summary

Problems solved by technology

[0006] (2) The slab is heated at a high temperature of 1400°C, which has reached the limit level of the heating furnace; high temperature heating, large burning loss, and frequent repairs of the heating furnace result in low utilization and high energy consumption; the edge cracks of the hot-rolled coil are large, resulting in cold rolling The production process is difficult, the finished product rate is low, and the cost is high

However, due to the influence of halogen compounds, a good bottom layer cannot be formed in some parts