| Patent application number | Description | Published |
|---|
| 20090053097 | Fire-Resistant Steel Material Superior in Haz Toughness of Welded Joint and Method of Production of Same - The present invention provides a fire-resistant steel material superior in HAZ toughness of a welded joint which is high in high temperature yield strength at an envisioned fire temperature of 700 to 800° C. and is free of embrittlement of the welded joint even if exposed at this envisioned fire temperature and a method of production of the same, that is, a fire-resistant steel material of a composition containing, by mass %, C: 0.005% to less than 0.03%, Si: 0.01 to 0.50%, Mn: 0.05 to 0.40%, Cr: 1.50 to 5.00%, V: 0.05 to 0.50%, and N: 0.001 to 0.005% and restricted in contents of Ni, Cu, Mo, B, P, S, and O obtained by heating a steel slab to 1150 to 1300° C., then hot working or hot rolling the slab to an end temperature of 880 degrees or more, acceleratedly cooling the worked or rolled steel material under conditions of a cooling rate at a position of the slowest cooling rate of at least 2° C./sec or more, stopping this accelerated cooling at a temperature region where the surface temperature of the steel material becomes 350 to 600° C., and then allowing the material to cool. | 02-26-2009 |
| 20100047107 | STEEL MATERIAL SUPERIOR IN HIGH TEMPERATURE STRENGTH AND TOUGHNESS AND METHOD OF PRODUCTION OF SAME - A steel material superior in high temperature characteristics and toughness is provided, the fire resistant steel material containing by mass %, C: 0.001% to 0.030%, Si: 0.05% to 0.50%, Mn: 0.40% to 2.00%, Nb: 0.03% to 0.50%, Ti: 0.005% to less than 0.040%, and N: 0.0008% to less than 0.0050%, restricting P: 0.030% or less and S: 0.020% or less, and having a balance of Fe and unavoidable impurities, where the contents of C and Nb satisfy C—Nb/7.74≦0.004, and Ti-based oxides of a grain size of 0.05 to 10 μm are present in a density of 30 to 300/mm | 02-25-2010 |
| 20100078097 | STEEL MATERIAL SUPERIOR IN HIGH TEMPERATURE CHARACTERISTICS AND TOUGHNESS AND METHOD OF PRODUCTION OF SAME - A steel material superior in high temperature characteristics and toughness is provided, that is, a steel material containing, by mass %, C: 0.005% to 0.03%, Si: 0.05% to 0.40%, Mn: 0.40% to 1.70%, Nb: 0.02% to 0.25%, Ti: 0.005% to 0.025%, N: 0.0008% to 0.0045%, B: 0.0003% to 0.0030%, restricting P: 0.030% or less, S: 0.020% or less, Al: 0.03% or less, and having a balance of Fe and unavoidable impurities, where the contents of C and Nb satisfy | 04-01-2010 |
| 20100132855 | FIRE-RESISTANT STEEL SUPERIOR IN WELD JOINT REHEAT EMBRITTLEMENT RESISTANCE AND TOUGHNESS AND METHOD OF PRODUCTION OF SAME - The present invention provides high temperature strength and fire-resistant steel superior in weld joint reheat embrittlement resistance and toughness which is produced using steel of a room temperature strength of the 400 to 600N/mm | 06-03-2010 |
| 20100330387 | HIGH STRENGTH THICK STEEL MATERIAL AND HIGH STRENGTH GIANT H-SHAPE EXCELENT IN TOUGHNESS AND WELDABILITY AND METHODS OF PRODUCTION OF SAME - The present invention provides a high strength thick steel material excellent in toughness and weldability reduced in amount of C and amount of N, containing suitable amounts of Si, Mn, Nb, Ti, B, and O, having contents of C and Nb satisfying C—Nb/7.74≦0.004, having a density of Ti-containing oxides of a particle size of 0.05 to 10 μm of 30 to 300/mm | 12-30-2010 |
| 20110318218 | LOW SPECIFIC GRAVITY STEEL FOR FORGING USE EXCELLENT IN MACHINEABILITY - Steel for forging having high strength and superior machinability due to controlled cooling immediately after shaping by hot forging followed by tempering and having a lower specific gravity than ordinary steel for forging use, the steel containing C: 0.05 to 0.50%, Si: 0.01 to 1.50%, Mn: 3.0 to 7.0%, P: 0.001 to 0.050%, S: 0.020 to 0.200%, Al: 3.0 to 6.0%, Cr: 0.01 to 1.00%, and N: 0.0040 to 0.0200% and having a balance of Fe and unavoidable impurities. | 12-29-2011 |
| 20120085209 | CUTTING METHOD OF STEEL FOR MACHINE STRUCTURAL USE - The cutting method of steel for machine structural use includes: forming a mist by mixing a cutting fluid supplied at a supply rate of 0.01 ml/hour to 200 ml/hour and an oxidizing gas containing, by volume %, 21% to 50% of oxygen; and cutting the steel for machine structural use while the mist is blown on the cutting edge surface of a tool and the surface of the steel for machine structural use, wherein the steel for machine structural use includes, by mass %: C: 0.01% to 1.2%, Si: 0.005% to 3.0%, Mn: 0.05% to 3.0%, P: 0.001% to 0.2%, S: 0.001% to 0.35%, N: 0.002% to 0.035%, Al: 0.05% to 1.0%, and the balance consisting of Fe and inevitable impurities in which O is limited to 0.003% or less, and the amount of Al [Al %] and the amount of N [N %] satisfy [Al %]−(27/14)×[N %]≧0.05. | 04-12-2012 |
| 20120087825 | Pearlite-Based High Carbon Steel Rail Having Excellent Ductility And Process For Production Thereof - This high-carbon pearlitic steel rail having excellent ductility, includes: in terms of percent by mass, C: more than 0.85% to 1.40%; Si: 0.10% to 2.00%; Mn: 0.10% to 2.00%; Ti: 0.001% to 0.01%; V: 0.005% to 0.20%; and N: less than 0.0040%, with the balance being Fe and inevitable impurities, wherein contents of Ti and V fulfill the following formula (1), and a rail head portion has a pearlite structure. | 04-12-2012 |
