| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably manufacture an electrical steel sheet having excellent high-frequency core loss, without causing difference in properties e.g. cold rollability, as compared with those of the ordinary electrical steel sheet. <P>SOLUTION: The electrical steel sheet with excellent high-frequency core loss contains, by mass, ≤0.06% C, 1.5 to 6.5% Si, 0.05 to 3.0% Mn, ≤0.30% P, ≤0.040% S or Se, ≤2.50% Al, 2.0 to 30.0% Cu and ≤0.0040% N and does not contain a metallic phase composed of Cu in the inner part of the steel. As to its manufacturing method, heat treatment is carried out in such a way that a step of cooling from a temperature region not lower than 800°C where no austenite phase is formed in the steel even at a maximum ultimate temperature is performed by applying cooling down to ≤300°C at ≥40°C/s cooling rate. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
