摘要:
The present invention relates to a process for producing a non-oriented silicon steel sheet having a low watt loss and an improved magnetic flux density. Generally, increasing the content of silicon and aluminum in a steel reduces the watt loss of the final product but deteriorates the magnetic flux density. Also, increasing the finishing temperature of a steel sheet or to increase the size of the crystal grains of the final product reduces the watt loss of the final product but also decreases the magnetic flux density.In accordance with the present invention, a grade S7 or grade S8 non-oriented electromagnetic steel sheet exhibiting such excellent magnetic properties at a high magnetic field that the magnetic flux density B.sub.50 is 1.67 tesla or more, the watt loss W.sub.15/50 is 2.70 W/kg or less (0.50 mm thick), and the watt loss W.sub.15/50 is 2.20 W/kg or less (0.35 mm thick) is produced by subjecting a high aluminum electromagnetic steel containing not less than 2.5% silicon and not less than 1.0% aluminum to cold-rolling at a high reduction ratio before finishing-annealing and by subjecting the cold-rolled steel sheet or strip to finishing-annealing at a high temperature of 1050.degree. C. or more for a very short period of from 3 to less than 60 seconds.
摘要:
In the production of non-oriented electrical steel sheets, it has been attempted to decrease the watt loss, e.g., by adding Sn to silicon steels, but in such a case the relationship between the watt loss and the magnetic flux density falls within the curves 1 and 1' in FIG. 1. The addition of boron is therefore unsatisfactory for meeting the recent demand for improving the magnetic properties of a non-oriented electrical steel sheet over those indicated by the curve 3.In the present invention, the combined addition of Sn and B and/or sol. Al results in the development of (110) and (100) textures, which are desirable for the magnetic properties.A non-oriented electrical steel sheet according to the present invention consists of:at most 0.015% carbon,0.3% to 2.0% silicon,0.02% to 0.20% tin,and optionally1.0% to 1.5% manganese,and(a) 0.005% to 0.10% acid-soluble aluminium,at most 0.007% nitrogen,at most 0.005% boron,the weight ratio of the boron content/nitrogen content being from 0.5 to 1.5balance iron and unavoidable impurities, or when manganese is present in said steel either,(b) 0.1% to 0.2% acid-soluble aluminium balance iron and unavoidable impurities, or (a).
摘要:
A method for manufacturing non-oriented electrical steel sheet and strip having no ridging characterized in that, non-oriented electrical steel sheet and strip is manufactured by casting molten silicon steel into a slab, hot-rolling, cold-rolling and annealing, said molten silicon steel, being controlled so as to give a composition, at the time of hot-rolling, comprising C 2.0% and also C .gtoreq. 1/100 [(Si + Al) - 0.75]% with the remainder being iron and unavoidable impurities.
摘要:
Process for producing non-directional electric steel sheets free from ridging, comprising preparing slabs by continuous casting from molten steel comprising not more than 0.04% C, 1.5 to 4.0% Si, not more than 1.0% Al, the balance being Fe and unavoidable impurities, hot rolling, cold rolling and annealing the slabs, characterized in that the slab is subjected to breaking-down with a reduction rate between 10 to 70% in the sheet thickness direction at a temperature between 1000.degree. and 1300.degree. C, and subsequently the required treatments are done.
摘要:
In a conventional process for producing a semi-processed non-oriented electrical steel sheet, the silicon or aluminum content of a hot-rolled steel strip is high, especially in the case of producing a high-grade electrical sheet which has a low watt loss. However, a high silicon or aluminum content disadvantageously results in a decrease in the magnetic flux density.A decrease in the watt loss and an increase in the magnetic flux density in semi-processed non-oriented electrical steel sheets as compared with conventional high-grade semi-processed non-oriented electrical steel sheets can be achieved by making the silicon content, which increases resistivity, low, i.e. from 0.1 to 1.0%, and the manganese content, which is effective for improving the texture, high i.e. from 0.75 to 1.5% and by subjecting the starting material, having a low silicon content, and a high manganese content to an appropriate production process for controlling texture.
摘要:
In the production of non-oriented electrical steel sheets, it has been attempted to decrease the watt loss, e.g., by adding Sn to silicon steels, but in such a case the relationship between the watt loss and the magnetic flux density falls within the curves 1 and 1' in FIG. 1. The addition of boron is therefore unsatisfactory for meeting the recent demand for improving the magnetic properties of a non-oriented electrical steel sheet over those indicated by the curve 3.In the present invention, the combined addition of Sn and B and/or sol. Al results in the development of (110) and (100) textures, which are desirable for the magnetic properties.A non-oriented electrical steel sheet according to the present invention consists of:at most 0.015% carbon,0.3% to 2.0% silicon,0.02% to 0.20% tin,and optionally1.0% to 1.5% manganese,and(a) 0.005% to 0.10% acid-soluble aluminium,at most 0.007% nitrogen,at most 0.005% boron,the weight ratio of the boron content/nitrogen content being from 0.5 to 1.5balance iron and unavoidable impurities, or when manganese is present in said steel either,(b) 0.1% to 0.2% acid-soluble aluminium balance iron and unavoidable impurities, or (a).