Patent ID: 6550122
Filing Date: 2003-04-22
Classification: B21B,B21D,C21D,F16G,Y10T

Abstract:
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 760-850Â° C. and in an atmosphere including 1-10% of hydrogen and having a dew point ranging from âˆ’7 to 0Â° C., or in a nitrogen atmosphere including 1-30% of hydrogen and having a dew point ranging from âˆ’70 to âˆ’40Â° C., said maraging steel being recrystallized at a temperature of about 760Â° C.