Manufacturing methods and its surface treatment agent of excellent non-oriented electrical steel sheet of film properties after stress relief annealing

摘要

PURPOSE:To improve seizure resistance at the time of stress relief annealing and lubricity and insulating property after annealing by applying baking treatment to a steel sheet by suing a surface treating agent prepared by adding specific highly heat resistant coarse-grained resin to a chromate - organic resin type treatment solution. CONSTITUTION:A surface treating agent which consists of 100 pts.wt. CrO3, 20-40 pts.wt. oxide selected from the oxides of Al, Mg, Ca, and Zn, 10-60 pts.wt. (expressed in terms of solids) of fine-grained emulsion solution of resin (acrylic, styrene, vinyl acetate homopolymer and/or copolymer thereof) of 0.2-0.5mum grain size, and 1-30 pts.wt. of resin (polymethyl methacrylate, polyacrylonitrile, etc.) of 1-50mum grain size and/or copolymer and crosslinked material thereof is prepared. After this treating agent is applied to a nonoriented silicon steel sheet, baking treatment is carried out.