公开(公告)号：US09976203B2

公开(公告)日：2018-05-22

申请号：US13747451

申请日：2013-01-22

Applicant: ArcelorMittal

Inventor： Hyun Jo Jun ,  Narayan Subramaniam Pottore ,  Nina Michailovna Fonstein ,  Oleg N. Yakubovsky

IPC: C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/08 ,  C22C38/00

CPC classification number: C22C38/14 ,  C22C38/00 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12

Abstract: A cold rolled, annealed TRIP steel sheet which has a composition including (in wt. %): C: 0.1-0.3; Mn: 4-10, Al: 0.05-5, Si: 0.05-5; and Nb: 0.008-0.1, the remainder being iron and inevitable residuals. The cold rolled sheet has an ultimate tensile strength of at least 1000 MPa, and a total elongation of at least 15%. The cold rolled sheet may have at least 20% retained austenite in its microstructure and may have greater than 50% lath-type annealed ferrite structure. The cold rolled sheet may have an ultra fine grain size of less than 5 micron for the retained austenite and ferrite.