| 摘要 |
PURPOSE:To obtain the extremely low-iron loss grain-oriented electrical steel sheet by treating a steel sheet with a specific treating liquid prior to stress impartation at the time of obtaining the electrical steel sheet by the effect of magnetic domain control, mirror finishing treatment and tension impartation. CONSTITUTION:The grain-oriented electrical steel sheet which is formed with linear or dotty grooves of <=0.4mu surface roughness Ra of the base iron, >5mu depth and <=300 width on the plate surface at 2 to 15mm intervals in the direction of 45 to 90 deg. with the rolling direction, is subjected to finish annealing and contains <=4.5% Si is used. This steel sheet is subjected to a tension coating treatment at over 759 deg.C to 950 deg.C, by which the ultralow iron loss grain-oriented electrical steel sheet is obtd. The steel sheet is immersed for 10 to 180 seconds in an aq. soln. of 2 to 30% sulfuric acid or sulfate as the concn. of the sulfuric acid and is then washed and dried. As a result, the wettability of the coating liquid with the base iron of the steel sheet having the low roughness like the above-mentioned steel sheet is improved and the adhesion to the steel sheet is improved. The tension impartation to the steel sheet is thus easily attained. |
