Method of manufacturing laminated ring

A method of manufacturing a laminated ring, comprising the steps of:

• preparing a cylindrical drum by welding opposite ends of a thin sheet of a maraging steel;
• effecting a first solution treatment on said cylindrical drum;
• thereafter, severing said cylindrical drum into a plurality of rings each having a predetermined width;
• rolling said rings;
• effecting a second solution treatment on said rings which have been rolled;
• thereafter, correcting a circumferential length of each of said rings;
• thereafter, aging and nitriding the rings;
• and
• stacking the aged and nitrided rings into a laminated ring;
• wherein said first solution treatment and said second solution treatment are effected simultaneously for the same period of time using one heating furnace, each of said treatments being performed at a temperature range of from about 760-850° C. and in an atmosphere including 1-10% of hydrogen and having a dew point ranging from −7 to 0° C., or in a nitrogen atmosphere including 1-30% of hydrogen and having a dew point ranging from −70 to −40° C., said maraging steel being recrystallized at a temperature of about 760° C.