Invention Grant
- Patent Title: Method for manufacturing of high strength cold rolled steel sheet of excellent phosphatability
- Patent Title (中): 具有优异的磷酸盐性的高强度冷轧钢板的制造方法
-
Application No.: US13387761Application Date: 2010-07-27
-
Publication No.: US08668789B2Publication Date: 2014-03-11
- Inventor: Junichiro Hirasawa , Naoto Yoshimi , Hiroki Nakamaru , Kohei Hasegawa , Hideyuki Tsurumaru , Keita Yonetsu , Hideyuki Takahashi , Masato Sasaki
- Applicant: Junichiro Hirasawa , Naoto Yoshimi , Hiroki Nakamaru , Kohei Hasegawa , Hideyuki Tsurumaru , Keita Yonetsu , Hideyuki Takahashi , Masato Sasaki
- Applicant Address: JP Tokyo
- Assignee: JFE Steel Corporation
- Current Assignee: JFE Steel Corporation
- Current Assignee Address: JP Tokyo
- Agency: Young & Thompson
- Priority: JP2009-176115 20090729
- International Application: PCT/JP2010/062984 WO 20100727
- International Announcement: WO2011/013837 WO 20110203
- Main IPC: C21D6/00
- IPC: C21D6/00 ; C21D1/52 ; C21D1/26

Abstract:
A method for the manufacturing of high strength cold rolled steel sheets includes continuously annealing a cold rolled steel sheet that has a composition containing C: 0.05-0.3% mass, Si: 0.6-3.0% mass, Mn: 1.0-3.0% mass, P: ≦0.1% mass, S: ≦0.02% mass, Al: 0.01-1% mass, N: ≦0.01% mass, and Fe and inevitable impurities: balance, in a manner such that the cold rolled steel sheet is heated in a furnace using an oxidizing burner to a steel sheet temperature of ≧700° C., then soak-annealed in a reducing atmosphere furnace at 750-900° C., then cooled so the average cooling rate between 500° C. and 100° C. is ≧50° C./s. High-Si cold rolled steel sheets with high strength and good phosphatability while containing Si≧0.6% are obtained without controlling conditions so as to increase the dew point in the reducing atmosphere in the soaking furnace or to increase the vapor hydrogen partial pressure ratio.
Public/Granted literature
- US20120186707A1 METHOD FOR MANUFACTURING OF HIGH STRENGTH COLD ROLLED STEEL SHEET OF EXCELLENT PHOSPHATABILITY Public/Granted day:2012-07-26
Information query