Patent application number | Description | Published |
20130243641 | ROLLED STEEL BAR OR WIRE FOR HOT FORGING - A rolled steel bar or a wire rod for hot forging capable of coping with both bending/surface fatigue strength of components and machinability at a high level includes: a composition containing, in mass %, C: 0.1 to 0.25%, Si: 0.01 to 0.10%, Mn: 0.4 to 1.0%, S: 0.003 to 0.05%, Cr: 1.60 to 2.00%, Mo: 0.10% or less (including 0%), Al: 0.025 to 0.05%, and N: 0.010 to 0.025%, where a value of fn1 represented in a following formula (1) satisfies 1.82≦fn1≦2.10: fn1=Cr+2×Mo (1); impurities containing P: 0.025% or less, Ti: 0.003% or less, and O (oxygen): 0.002% or less; and a cross section in which a maximum value/a minimum value of an average ferrite grain diameter is 2.0 or less when measurement by observation is randomly carried out in 15 visual fields with an area per visual field set to be 62500 μm | 09-19-2013 |
20140363329 | ROLLED STEEL BAR OR WIRE ROD FOR HOT FORGING - A rolled steel bar or wire rod having hot surface fatigue strength, wear resistance, and machinability even after hot forging has a composition containing C, Si, Mn, S, Cr, Mo (optional), Al, and N, with the balance being Fe and impurities. The chemical composition satisfies that fn1 defined by Formula (1) is 1.60 to 2.10. The structure of the rolled steel bar or wire rod for hot forging includes a ferrite-pearlite structure, a ferrite-pearlite-bainite structure, or a ferrite-bainite structure. A maximum value/a minimum value of average ferrite grain size, which is observed and measured randomly in 15 visual fields each having an area of 62500 μm | 12-11-2014 |
Patent application number | Description | Published |
20130273393 | STEEL FOR COLD FORGING/NITRIDING, STEEL MATERIAL FOR COLD FORGING/NITRIDING, AND COLD-FORGED/NITRIDED COMPONENT - A steel for cold forging/nitriding has, by mass percent, C: 0.01 to 0.15%, Si≦0.35%, Mn: 0.10 to 0.90%, P≦0.030%, S≦0.030%, Cr: 0.50 to 2.0%, V: 0.10 to 0.50%, Al: 0.01 to 0.10%, N≦0.0080%, and O≦0.0030%, further according to need a specific amount of one or more elements selected from Mo, Cu, Ni, Ti, Nb, Zr, Pb, Ca, Bi, Te, Se and Sb, with the balance being Fe and impurities, and further satisfying the conditions of [399×C+26×Si+123×Mn+30×Cr+32×Mo+19×V≦160], [20≦(669.3×log | 10-17-2013 |
20140034194 | STEEL FOR NITRIDING AND NITRIDED COMPONENT - A steel for nitriding having a chemical composition consisting of, by mass percent, C: 0.07-0.14%, Si: 0.10-0.30%, Mn: 0.4-1.0%, S: 0.005-0.030%, Cr: 1.0-1.5%, Mo: ≦0.05% (including 0%), Al: 0.010% or more to less than 0.10%, V: 0.10-0.25%, optionally at least one element selected from Cu: ≦0.30% and Ni: ≦0.25% [0.61Mn+1.11Cr+0.35Mo+0.47≦2.30], and the balance of Fe and impurities. P, N, Ti and O among the impurities are P: ≦0.030%, N: ≦0.008%, Ti: ≦0.005%, and O: ≦0.0030%. The steel is easily subjected to cutting before nitriding and suitable for use as an automobile ring gear. The nitrided component having a surface hardness of 650-900 HV, core hardness being ≧150 HV, and effective case depth of ≧0.15 mm has excellent bending fatigue strength and surface fatigue strength although the content of Mo is as low as ≦0.05% and has a small amount of expansion caused by nitriding. | 02-06-2014 |
Patent application number | Description | Published |
20140246126 | METHOD FOR PRODUCING STEEL COMPONENT - A method for producing a steel component by performing the treatments of the following sequentially steps 1 and 2 to a steel material containing, by mass %, C: 0.15 to 0.25%, Si: 0.01 to 0.10%, Mn: 0.50 to 0.80%, S: 0.003 to 0.030%, Cr: 0.80 to 1.20%, Mo: 0.30 to 0.45%, Al: 0.015 to 0.050%, and N: 0.010 to 0.025%, wherein Cr/Mn is 1.3 to 2.4, the balance being Fe and impurities, and contents of P and O among the impurities are P: not more than 0.010%, and O: not more than 0.0020%:
| 09-04-2014 |
20150027591 | STEEL MATERIAL FOR NITRIDING AND NITRIDED COMPONENT - A steel material for nitriding has a composition comprising, by mass percent, C: more than 0.15% and not more than 0.35%, Si≦0.20%, Mn: 0.10 to 2.0%, P≦0.030%, S≦0.050%, Cr: 0.80 to 2.0%, V: 0.10 to 0.50%, Al: 0.01 to 0.06%, N≦0.0080%, O≦0.0030%, and optionally one or more elements of Mo, Cu, Ni, Ti, Nb, Zr, Pb, Ca, Bi, Te, Se and Sb, the balance being Fe and impurities. The composition satisfies the conditions of [20≦(669.3×log | 01-29-2015 |
20150053311 | NITRIDED STEEL MEMBER AND MANUFACTURING METHOD THEREOF - A nitrided steel member including an iron nitride compound layer formed on a surface of a steel member having predetermined components, wherein: in X-ray diffraction peak intensity IFe | 02-26-2015 |
20150059933 | STEEL FOR COLD FORGING/NITRIDING, STEEL MATERIAL FOR COLD FORGING/NITRIDING, AND COLD-FORGED/NITRIDED COMPONENT - A steel comprises, by mass percent, C: 0.10 to 0.15%, Si: not less than 0.02% and less than 0.10%, Mn: more than 0.90% and not more than 2.50%, P≦0.030%, S≦0.050%, Cr: 0.80 to 2.0%, V: 0.05 to 0.50%, Al: 0.01 to 0.07%, N≦0.0080%, O≦0.0030%, and one or more selected from Mo, Cu, Ni, Ti, Nb, Zr, Pb, Ca, Bi, Te, Se and Sb, the balance being Fe and impurities. The composition satisfies [35≦Mn/S≦200], [20≦(669.3×log | 03-05-2015 |