发明授权
US06248191B1 Method for producing ultra-high strength, weldable steels with superior toughness
失效
具有优异韧性的超高强度,可焊接钢的生产方法
- 专利标题: Method for producing ultra-high strength, weldable steels with superior toughness
- 专利标题(中): 具有优异韧性的超高强度,可焊接钢的生产方法
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申请号: US09123858申请日: 1998-07-28
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公开(公告)号: US06248191B1公开(公告)日: 2001-06-19
- 发明人: Michael J. Luton , Jayoung Koo , Narasimha-Rao V. Bangaru , Clifford W. Petersen , Hiroshi Tamehiro , Hitoshi Asahi , Takuya Hara , Masaaki Sugiyama
- 申请人: Michael J. Luton , Jayoung Koo , Narasimha-Rao V. Bangaru , Clifford W. Petersen , Hiroshi Tamehiro , Hitoshi Asahi , Takuya Hara , Masaaki Sugiyama
- 主分类号: C21D800
- IPC分类号: C21D800
摘要:
A method is provided for producing an ultra-high strength steel having a tensile strength of at least about 900 MPa (130 ksi), a toughness as measured by Charpy V-notch impact test at −40° C. (−40° F.) of at least about 120 joules (90 ft-lbs), and a microstructure comprising predominantly fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof, transformed from substantially unrecrystallized austenite grains and comprising iron and specified weight percentages of the additives: carbon, silicon, manganese, copper, nickel, niobium, vanadium, molybdenum, chromium, titanium, aluminum, calcium, Rare Earth Metals, and magnesium. A steel slab is heated to a suitable temperature; the slab is reduced to form plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; said plate is further reduced in one or more hot rolling passes in a second temperature range below said first temperature range and above the temperature at which austenite begins to transform to ferrite during cooling; said plate is quenched to a suitable Quench Stop Temperature; and said quenching is stopped and said plate is allowed to air cool to ambient temperature.