Patent application number | Description | Published |
20080251160 | High-Strength Cold-Rolled Steel Sheet Excellent in Uniform Elongation and Method for Manufacturing Same - A high-strength cold-rolled steel sheet excellent in uniform elongation, including in percent by mass:
| 10-16-2008 |
20080251161 | High Strength Cold Rolled Steel Sheet and Plated Steel Sheet Excellent in the Balance of Strength and Workability - A high-strength cold-rolled steel sheet exhibiting an excellent strength-workability balance, including in percent by mass:
| 10-16-2008 |
20090014095 | HIGH-STRENGTH COLD ROLLED STEEL SHEET EXCELLING IN CHEMICAL TREATABILITY - The invention provides a high strength cold rolled steel sheet having excellent chemical conversion treatment property stably even Mo is added aiming high strengthening. The surface property of the cold rolled steel sheet satisfies that the characteristic of 10 μm or more of the maximum depth (Ry) of the unevenness and 30 μm or less of the average spacing (Sm) of the unevenness, and that either one or more preferably both of, the characteristic of the load length ratio (tp40) of the unevenness of the surface is 20% or less, and the characteristic of the difference of the load length ratios (tp60) and (tp40) is 60% or more, is satisfied, and the crack of 3 μm or less width and 5 μm or more depth does not exist on the surface. | 01-15-2009 |
20090053096 | HIGH-STRENGTH COLD-ROLLED STEEL SHEET EXCELLENT IN COATING ADHESION, WORKABILITY AND HYDROGEN EMBRITTLEMENT RESISTANCE, AND STEEL COMPONENT FOR AUTOMOBILE - A cold rolled steel sheet satisfying on the basis of percent by mass the chemical composition of 0.06-0.6% C, 0.1-2% Si, 0.01-3% Al, 1-4% Si+Al, 1-6% Mn, Si/Mn≦0.40, in which there exists 10 or more pieces/100 μm | 02-26-2009 |
20090238713 | ULTRAHIGH-STRENGTH STEEL SHEET - The invention relates to an ultrahigh-strength thin steel sheet excellent in the hydrogen embrittlement resistance, the steel sheet including, by weight %, 0.10 to 0.60% of C, 1.0 to 3.0% of Si, 1.0 to 3.5% of Mn, 0.15% or less of P, 0.02% or less of S, 1.5% or less of Al, 0.003 to 2.0% of Cr, and a balance including iron and inevitable impurities; in which grains of residual austenite have an average axis ratio (major axis/minor axis) of 5 or more, the grains of the residual austenite have an average minor axis length of 1 μm or less, and the grains of the residual austenite have a nearest-neighbor distance between the grains of 1 μm or less. | 09-24-2009 |
20090277547 | HIGH-STRENGTH STEEL SHEETS AND PROCESSES FOR PRODUCTION OF THE SAME - A high strength steel sheet with both excellent elongation and stretch-flanging performance is provided. | 11-12-2009 |
20100080728 | HIGH-STRENGTH THIN STEEL SHEET - The present invention is the thin steel sheet containing C, Si, Mn, P, S, Al, Mo, Ti, B, and N wherein a value Z calculated by the equation described below is 2.0-6.0, an area ratio against all the structure is 1% or above for retained austenite and 80% or above for total of bainitic ferrite and martensite, a mean axis ratio of the retained austenite crystal grain is 5 or above, and tensile strength is 980 MPa or above. | 04-01-2010 |
20100172786 | HIGH-STRENGTH STEEL SHEET HAVING EXCELLENT ELONGATION, STRETCH FLANGEABILITY AND WELDABILITY - The present invention provides a high-strength steel sheet which has a 980 MPa class tensile strength as well as has excellent elongation, stretch flangeability and weldability, and also has excellent anti-delayed fraction property. The high-strength steel sheet comprises steel satisfying: C: 0.12 to 0.25%, Si: 1.0 to 3.0%, Mn: 1.5 to 3.0%, P: 0.15% or less, S: 0.02% or less, Al: 0.4% or less, and comprising the remnant made from iron and unavoidable impurities, wherein a ratio of the contents of Si and C (Si/C) is within the range from 7 to 14 in terms of a mass ratio, and a microstructure in a longitudinal section comprises, by an occupancy ratio based on the entire structure, 1) bainitic ferrite: 50% or more, 2) lath-type residual austenite: 3% or more, and 3) block-type residual austenite: 1% or more to ½×occupancy ratio of lath-type residual austenite, and 4) average size of block-type second phase is 10 μm or less. | 07-08-2010 |
20100221138 | HIGH-STRENGTH COMPOSITE STEEL SHEET HAVING EXCELLENT MOLDABILITY AND DELAYED FRACTURE RESISTANCE - The present invention provides a high-strength composite steel sheet which has a tensile strength of 980 MPa class as well as excellent and excellent anti-delayed fraction property, and also has excellent spot-weldability. The high-strength composite steel sheet comprises a steel satisfying: C: 0.10 to 0.25% (% by mass in case of a chemical component, the same shall apply hereinafter), Si: 1.0 to 3.0%, Mn: 1.5 to 3.0%, P: 0.15% or less, S: 0.02% or less, Al: 0.4% or less, and comprising the remnant made from iron and unavoidable impurities; the contents of Si, Al, Mn and Cr satisfy the relationship of “(Si+Al)/Mn or (Si+Al)/(Mn+Cr)=0.74 to 1.26”; and microstructure is specified. | 09-02-2010 |