Patent Number: 6,761,780

Title: Method of manufacturing a high Mn non-magnetic steel sheet for cryogenic temperature use

Abstract: A method of manufacturing a high Mn non-magnetic steel sheet having low permeability at a cryogenic temperature suitable for use in large scale particle accelerators, the method comprises rolling a steel material containing, on the wt % basis, from 0.05 to 0.18% of C, from 26.0 to 30.0% of Mn, from 5.0 to 10.0% of Cr, 0.05 to 0.15% of N and, optionally, from 0.50 to 5.0% of Ni, in which a rolling start temperature is from 1050 to 1200.degree. C. and a rolling end temperature is from 700 to 1000.degree. C. Further, a cold rolled sheet is annealed at an annealing temperature for cold rolled sheet of from 1050 to 1200.degree. C. and cooled after annealing, the annealed sheet being preferably applied with temper rolling under control for the strength by varying a draft ratio.

Inventors: Morito; Nobuyuki (Okayama, JP), Nohara; Kiyohiko (Tokyo, JP), Kobori; Katsuhiro (Chiba, JP), Nishiike; Ujihiro (Tokyo, JP), Yamashita; Takako (Chiba, JP)

Assignee: JFE Steel Corporation

International Classification: C22C 38/38 (20060101); C22C 38/58 (20060101); C22C 38/00 (20060101); C21D 8/02 (20060101); C21D 008/12 ()

Expiration Date: 07/12012