发明授权
- 专利标题: High strength thick-gauge steel plate superior in weldability and having tensile strength of 780 MPA or more and method of production of same
- 专利标题(中): 焊接性优异,拉伸强度为780MPa以上的高强度粗钢板及其制造方法
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申请号: US12867731申请日: 2009-10-22
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公开(公告)号: US08048367B2公开(公告)日: 2011-11-01
- 发明人: Manabu Hoshino , Masaaki Fujioka , Youichi Tanaka , Masanori Minagawa
- 申请人: Manabu Hoshino , Masaaki Fujioka , Youichi Tanaka , Masanori Minagawa
- 申请人地址: JP Tokyo
- 专利权人: Nippon Steel Corporation
- 当前专利权人: Nippon Steel Corporation
- 当前专利权人地址: JP Tokyo
- 代理机构: Birch, Stewart, Kolasch & Birch, LLP
- 优先权: JP2008-273097 20081023
- 国际申请: PCT/JP2009/068546 WO 20091022
- 国际公布: WO2010/047416 WO 20100429
- 主分类号: C22C38/04
- IPC分类号: C22C38/04 ; C22C38/00 ; C21D8/02 ; C21D8/00
摘要:
The present invention provides high strength thick-gauge steel plate superior in weldability and having a tensile strength of 780 MPa or more and provides a method of production of the high strength thick-gauge steel plate by omitting tempering heat treatment in the production. The high strength thick-gauge steel plate of the present invention is high strength thick-gauge steel plate containing, by mass %, C: 0.030 to 0.055%, Mn: 2.4 to 3.5%, P: 0.01% or less, S: 0.0010% or less, Al: 0.06 to 0.10%, B: 0.0005 to 0.0020%, and N: 0.0015 to 0.0060%, having a weld cracking susceptibility parameter Pcm of 0.18% to 0.24%, and comprised mainly of martensite. The method of production of high strength thick-gauge steel plate of the present invention comprises heating a steel slab or cast slab having a predetermined composition of ingredients to 950 to 1100° C., rolling it at 820° C. or more, then starting accelerated cooling from 700° C. or more by a cooling rate of 8 to 80° C./sec and stopping the accelerated cooling at room temperature to 350° C.