Abstract: A method of annealing a metal member includes: disposing a first heater in an inner space of a hollow cylindrical metal member having an inner peripheral surface provided with plural teeth protruding toward a central direction, the first heater radiating infrared light and being disposed so as to extend parallel to a direction of a central axis of the metal member; heating the metal member from the inner space with the first heater; and gradually cooling the metal member after heating.

Abstract: Provided is a method of annealing a metal member, including: disposing a first heater in an inner space of a hollow cylindrical metal member having an inner peripheral surface provided with plural teeth protruding toward a central direction, the first heater radiating infrared light and being disposed so as to extend parallel to a direction of a central axis of the metal member; heating the metal member from the inner space with the first heater; and gradually cooling the metal member after heating.

Abstract: A continuous annealing facility comprised of a heating zone, soaking zone, and cooling zone is used for continuous annealing of a steel strip having a Curie point (Tc) by an annealing temperature over Tc during which the heat treatment in the heating zone is divided into three regions, in a first heating zone, a radiant heating means using gas heating and/or a radiant heating means using electric heaters is used to heat the steel strip to less than Tc?50° C., in a next second heating zone, the heated steel strip is heated by a solenoid coil type high frequency induction heating means to a region of Tc?30° C. to Tc?5° C., and, in a final third heating zone, the heated steel strip is heated by a radiant heating means using gas heating and/or a radiant heating means using electric heaters to a treatment target temperature over Tc to thereby anneal a steel strip having a Curie point uniformly in the longitudinal direction.

Abstract: Disclosed is an annealing separator for production for grain-oriented electrical steel sheet, containing one or more compound selected from the following general formula;?Mg.sub.1-x M.sup.3+.sub.x !O ?Mg.sub.1-x M.sup.2+.sub.x !O or ?Mg.sub.1-x M.sup.2+.sub.x1 M.sup.3+.sub.x2 !OwhereM.sup.2+ is at least one bivalent element selected from the group consisting of Be, Ca, Ba, Sr, Sn, Mn, Fe, Co, Ni, Cu, Zn;M.sup.3+ is at least one tervalent element selected from the group consisting of Al, Fe, Cr, Co, B, Ti, Sb;0.01.ltoreq.x.ltoreq.0.40; x=x1+x2This annealing separator having a lower melting point and higher degree of reactivity is applied on the decarburization annealed strip, and improves the properties of the glass film, especially uniform film appearance and good sealing effect, and magnetic properties.