公开(公告)号：US20190010585A1

公开(公告)日：2019-01-10

申请号：US16130335

申请日：2018-09-13

Applicant: ARCELORMITTAL

Inventor： Hyun Jo JUN ,  Narayan S. POTTORE ,  Nina Michailovna FONSTEIN

IPC: C22C38/12 ,  C21D9/40 ,  C22C38/00 ,  C22C38/04 ,  C22C38/02 ,  C22C38/06

Abstract: A dual phase steel sheet is provided. The steel sheet has a microstructure containing ferrite and tempered martensite, a tensile strength of at least 980 MPa, a total elongation of at least 15%, and a hole expansion ratio of at least 15%. The dual phase steel sheet has a composition including 0.2 to 0.3 wt. % C, 1.6 to 2.5 wt. % Si and 1.75 to 2.5 wt. % Mn. A method for producing the dual phase steel sheet is also provided.

公开(公告)号：US20200080177A1

公开(公告)日：2020-03-12

申请号：US16685315

申请日：2019-11-15

Applicant: ArcelorMittal

Inventor： Hyun Jo JUN ,  Narayan S. POTTORE ,  Nina Michailovna FONSTEIN

IPC: C22C38/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C21D9/40

Abstract: A method for producing a dual phase steel sheet is provided. The method includes providing a dual phase hot rolled steel sheet having a microstructure including ferrite and martensite and a composition including 0.1 to 0.3 wt. % C, 1.5 to 2.5 wt. % Si and 1.75 to 2.5 wt. % Mn. The steel sheet is annealed at a temperature from 750 to 875° C., water quenched to a temperature from 400 to 420° C. and subject to overaging at the temperature from 400 to 420° C. to convert the martensite in the hot rolled steel sheet to tempered martensite. The overaging is sufficient to provide the hot rolled steel sheet with a hole expansion ratio of at least 15%.