| 摘要 |
PURPOSE:To obtain a magnetically soft material reduced in iron loss and having high magnetic flux density by hot-extruding a steel having increased Si and Al contents into a steel tube having an equiaxed recrystallized ferrite grain structure, forming the above tube into a thin-wall tube by means of rolling, and then carrying out the final annealing. CONSTITUTION:A cast billet of a steel having a composition consisting of, by weight, <=0.01% C, 0.8-4.5% Si, 0.05-1.0% Mn, 0.005-0.1% P, 0.005-0.1% S, 0.2-1.0% Al, and the balance Fe with inevitable impurities is hot-extruded at 850-1,150 deg.C, by which a steel tube practically free from working texture in the as-extruded state and consisting of equiaxed recrystallized ferrite grain structure is prepared. This tube is rolled, without being reheated, at a temp. between [60XSi(%)-90] deg.C and 300 deg.C and formed into a thin-wall tube of <=1mm thickness, followed by final annealing. By this method, a silicon steel tube free from fracture, etc., due to deterioration in ductility and having superior magnetic properties can be obtained. |
