Publication number: 20130008568
Abstract: A high-strength steel sheet includes, by mass %, C: 0.03% to 0.30%, Si: 0.08% to 2.1%, Mn: 0.5% to 4.0%, P: 0.05% or less, S: 0.0001% to 0.1%, N: 0.01% or less, acid-soluble Al: more than 0.004% and less than or equal to 2.0%, acid-soluble Ti: 0.0001% to 0.20%, at least one selected from Ce and La: 0.001% to 0.04% in total, and a balance of iron and inevitable impurities, in which [Ce], [La], [acid-soluble Al], and [S] satisfy 0.02?([Ce]+[La])/[acid-soluble Al]<0.25, and 0.4?([Ce]+[La])/[S]?50 in a case in which the mass percentages of Ce, La, acid-soluble Al, and S are defined to be [Ce], [La], [acid-soluble Al], and [S], respectively, and a microstructure includes 1% to 50% of martensite in terms of an area ratio.
Type:
Application
Filed:
May 10, 2011
Publication date:
January 10, 2013
Applicant:
NIPPON STEEL CORPORATION
Inventors:
Yoshihiro Suwa, Kenichi Yamamoto, Daisuke Maeda, Satoshi Hirose, Genichi Shigesato, Naoki Yoshinaga
Publication number: 20120077051
Abstract: In an embodiment of a steel sheet having high Young's modulus, the steel can include in terms of mass %, e.g., C: 0.0005 to 0.30%, Si: 2.3% or less, Mn: 2.7 to 5.0%, P: 0.15% or less, 0.015% or less, Mo: 0.15 to 1.5%, B: 0.0006 to 0.01%, and Al: 0.15% or less, with the remainder being Fe and unavoidable impurities. One or both of {110}<223> pole density and {110}<111> pole density in the ? sheet thickness layer can be 10 or more, and a Young's modulus in a rolling direction can be more than 230 GPa. Other embodiments can include, e.g., Mn: 0.1 to 5.0%, N: 0.01% or less, and one or more of Mo: 0.005 to 1.5%, Nb: 0.005 to 0.20%, Ti: at least 48/14×N (mass %) and 0.2% or less, and B: 0.0001 to 0.01%, at a total content of 0.015 to 1.91 mass %.
Type:
Application
Filed:
September 26, 2011
Publication date:
March 29, 2012
Applicant:
Nippon Steel Corporation
Inventors:
Natsuko Sugiura, Naoki Yoshinaga, Shunji Hiwatashi, Manabu Takahashi, Koji Hanya, Nobuyoshi Uno, Ryoichi Kanno, Akihiro Miyasaka, Takehide Senuma
Patent number: 8057913
Abstract: One aspect of the steel sheet having high Young's modulus includes in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 2.7 to 5.0%, P: 0.15% or less, S: 0.015% or less, Mo: 0.15 to 1.5%, B: 0.0006 to 0.01%, and Al: 0.15% or less, with the remainder being Fe and unavoidable impurities, wherein one or both of {110}<223> pole density and {110}<111> pole density in the ? sheet thickness layer is 10 or more, and a Young's modulus in a rolling direction is more than 230 GPa. Another aspect of the steel sheet having high Young's modulus includes, in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 0.1 to 5.0%, P: 0.15% or less, S: 0.015% or less, Al: 0.15% or less, N: 0.01% or less, and further comprises one or two or more of Mo: 0.005 to 1.5%, Nb: 0.005 to 0.20%, Ti: at least 48/14×N (mass %) and 0.2% or less, and B: 0.0001 to 0.01%, at a total content of 0.015 to 1.
Type:
Grant
Filed:
July 27, 2005
Date of Patent:
November 15, 2011
Assignee:
Nippon Steel Corporation
Inventors:
Natsuko Sugiura, Naoki Yoshinaga, Shunji Hiwatashi, Manabu Takahashi, Koji Hanya, Nobuyoshi Uno, Ryoichi Kanno, Akihiro Miyasaka, Takehide Senuma