Patent ID: 6833107
Filing Date: 2004-12-21
Classification: C21D,H05B,Y02P

Abstract:
A heat-treating furnace with a magnetic field comprising (a) a magnetic field-generating means constituted by one ring-shaped, permanent magnet assembly comprising a plurality of permanent magnet segments combined with their magnetization directions oriented such that a magnetic flux flows in a diameter direction, said permanent magnet segment being constituted by combining a plurality of permanent magnet pieces; and (b) a heat treatment means disposed in a center hole of said ring-shaped, permanent magnet assembly and comprising a cooling means, a heating means, and a heat-treating container for containing a heat-treating holder for holding a plurality of articles to be heat-treated in this order from outside,wherein said ring-shaped, permanent magnet assembly has an inner diameter of 120 mm or more, an outer diameter (D1) of 300 mm or more, and an axial length (H) of 100 mm or more, and wherein the axial length H and the outer diameter D1 of said ring-shaped, permanent magnet assembly meet the requirement of 2&lE;D1/H&lE;10.