Abstract: The present invention provides a steel for nitrocarburizing having excellent mechanical workability before nitrocarburizing, and showing excellent fatigue properties after nitrocarburizing, which is suitable for applying in mechanical structural components for automobiles etc. prepared by adjusting the composition so that it contains in mass %, C: 0.01% or more and less than 0.10%, Si: 1.0% or less, Mn: 0.5% to 3.0%, P: 0.02% or less, S: 0.06% or less, Cr: 0.3% to 3.0%, Mo: 0.005% to 0.4%, V: 0.02% to 0.5%, Nb: 0.003% to 0.15%, Al: 0.005% to 0.2%, and Sb: 0.0005% to 0.02%, and the balance including Fe and incidental impurities, and setting the area ratio of bainite phase to the whole microstructure to more than 50%.

Abstract: A method is provided with which a bearing steel, even when obtained from an ingot, is made to have a segregation part reduced in the degree of segregation and maximum inclusion diameter. The ingot contains 0.56-0.70 mass % C, 0.15-0.50 mass %, excluding 0.50 mass %, Si, 0.60-1.50 mass % Mn, 0.50-1.10 mass % Cr, 0.05-0.5 mass % Mo, up to 0.025 mass % P, up to 0.025 mass % S, 0.005-0.500 mass % Al, up to 0.0015 mass % O, and 0.0030-0.015 mass % N, with the remainder comprising Fe and incidental impurities. The ingot has a degree of segregation of 2.8 or less and a predicted value of the maximum diameter of inclusions present in 30,000 mm2 of the ingot, as calculated by extreme value statistics, of 60 ?m or less.

Abstract: The present invention provides bearing steel, comprising a chemical composition including by mass %, C: 0.56%?[% C]?0.70%, Si: 0.15%?[% Si]<0.50%, Mn: 0.60%?[% Mn]?1.50%, Cr: 0.50%?[% Cr]?1.10%, Mo: 0.05%?[% Mo]?0.5%, P: [% P]?0.025%, S: [% S]?0.025%, Al: 0.005%?[% Al]?0.500%, O: [% O]?0.0015%, N: 0.0030%?[% N]?0.015%, and remainder as Fe and incidental impurities.

Abstract: The present invention provides a steel for nitrocarburizing having excellent mechanical workability before nitrocarburizing, and showing excellent fatigue properties after nitrocarburizing, which is suitable for applying in mechanical structural components for automobiles etc. prepared by adjusting the composition so that it contains in mass %, C: 0.01% or more and less than 0.10%, Si: 1.0% or less, Mn: 0.5% to 3.0%, P: 0.02% or less, S: 0.06% or less, Cr: 0.3% to 3.0%, Mo: 0.005% to 0.4%, V: 0.02% to 0.5%, Nb: 0.003% to 0.15%, Al: 0.005% to 0.2%, and Sb: 0.0005% to 0.02%, and the balance including Fe and incidental impurities, and setting the area ratio of bainite phase to the whole microstructure to more than 50%.

Abstract: A pearlite rail contains, by % by mass, 0.70 to 1.0% C, 0.1 to 1.5% Si, 0.01 to 1.5% Mn, 0.001 to 0.035% P, 0.0005 to 0.030% S, and 0.1 to 2.0% Cr by mass with the balance being Fe and inevitable impurities, wherein a ?+? temperature range is 100° C. or lower.

Abstract: A method is provided with which a bearing steel, even when obtained from an ingot, is made to have a segregation part reduced in the degree of segregation and maximum inclusion diameter. The ingot contains 0.56-0.70 mass % C, 0.15-0.50 mass %, excluding 0.50 mass %, Si, 0.60-1.50 mass % Mn, 0.50-1.10 mass % Cr, 0.05-0.5 mass % Mo, up to 0.025 mass % P, up to 0.025 mass % S, 0.005-0.500 mass % Al, up to 0.0015 mass % O, and 0.0030-0.015 mass % N, with the remainder comprising Fe and incidental impurities. The ingot has a degree of segregation of 2.8 or less and a predicted value of the maximum diameter of inclusions present in 30,000 mm2 of the ingot, as calculated by extreme value statistics, of 60 ?m or less.

Abstract: According to the present invention, it is possible to obtain steel for nitrocarburizing having a predetermined chemical composition, a bainite area ratio exceeding 50% and excellent machinability by cutting before nitrocarburizing, and having strength and toughness equivalent to conventional steel, such as SCr420 carburized steel material, and excellent fatigue properties after nitrocarburizing.

Abstract: In an abrasion resistant welded steel pipe, each of a base material and a weld metal contains specific amounts of chemical composition. The base material of the abrasion resistant welded steel pipe has a Vickers hardness within the range of 150 to 250, and the weld metal has a Vickers hardness within the range of 230 to 350. A weld heat affected zone in the abrasion resistant welded steel pipe has a Vickers hardness within the range of 150 to 350. In the weld metal, the dispersion density of a sulfide having an aspect ratio of 5 or more and containing at least one selected from Fe, Mn, and Ti is 10 grains/mm2 or less. The abrasion resistant welded steel pipe that can be produced at high productivity and low cost with no reduction in weld crack resistance can be provided.

Abstract: A high strength spring steel suppresses ferrite decarburization in a surface layer of a predetermined wire rod manufactured by hot rolling therefrom and possesses excellent decarburization resistance, as compared to conventional high strength spring steel, by optimizing the amount of C, Si, Mn, Cr, Mo and Sb to be added. The spring steel contains, under a certain relationship: 0.35 mass %?C?0.45 mass %; 1.75 mass %?Si?2.40 mass %; 0.1 mass %?Mn?1.0 mass %; 0.01 mass %?Cr<0.50 mass %; 0.01 mass %?Mo?1.00 mass %; P?0.025 mass %; S?0.025 mass %; and O?0.0015 mass %; and at least one selected from 0.035 mass %?Sb?0.12 mass % and 0.035 mass %?Sn?0.20 mass %.

Abstract: A carburizing steel has a composition containing, in mass %, C: 0.1-0.35%; Si: 0.01-0.22%; Mn: 0.3-1.5%; Cr: 1.35-3.0%; P: 0.018% or less; S: 0.02% or less; Al: 0.015-0.05%; N: 0.008-0.015%; and O: 0.0015% or less, each being contained in an amount within a range satisfying formulas (1), (2) and (3) below, and the balance of the composition being Fe and incidental impurities, and the carburizing steel having microstructures before spheroidizing annealing such that a total microstructure proportion of ferrite and pearlite is 85% or more and an average ferrite grain size is 25 ?m or less. 3.1?{([% Si]/2)+[% Mn]+[% Cr]}?2.2 ??(1) [% C]?([% Si]/2)+([% Mn]/5)+2[% Cr]?3.0 ??(2) 2.5?[% Al]/[% N]?1.7 ??(3) [% M] represents content (in mass %) of element M.

Abstract: The present invention provides bearing steel, comprising a chemical composition including by mass %, C: 0.56%?[% C]?0.70%, Si: 0.15%?[% Si]<0.50%, Mn: 0.60%?[% Mn]?1.50%, Cr: 0.50%?[% Cr]?1.10%, Mo: 0.05%?[% Mo]?0.5%, P: [% P]?0.025%, S: [% S]?0.025%, Al: 0.005%?[% Al]?0.500%, O: [% O]?0.0015%, N: 0.0030%?[% N]?0.015%, and remainder as Fe and incidental impurities.

Abstract: An internal high hardness type pearlitic rail that has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, and the balance being Fe and incidental impurities, in which the value of [% Mn]/[% Cr] is greater than or equal to 0.3 and less than 1.0, where [% Mn] represents the Mn content, and [% Cr] represents the Cr content, and in which the internal hardness of a rail head that is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm is greater than or equal to 380 Hv and less than 480 Hv.

Abstract: An internal high hardness type pearlitic rail that has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, and the balance being Fe and incidental impurities, in which the value of [% Mn]/[% Cr] is greater than or equal to 0.3 and less than 1.0, where [% Mn] represents the Mn content, and [% Cr] represents the Cr content, and in which the internal hardness of a rail head that is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm is greater than or equal to 380 Hv and less than 480 Hv.

Abstract: A pearlitic steel railroad rail which comprises 0.75 to 0.84% C, 0.10 to 1.0% Si, 0.4 to 2.5% Mn, 0.035% or less P, 0.035% or less S, and 0.05 to 0.6% Nb, by weight. This rail has better wear resistance than the heretofore used pearlitic steel rail and sufficient ductility so cracks do not appear due to thermal dilation and contraction caused by a change of temperature. The rail is consequently very suitable for the use in a mine railroad.

Abstract: Disclosed is an aluminum alloy sheet having a chemical composition of an Si-containing Al--Mg--CU alloy. The aluminum alloy sheet exhibits a streak-shaped modulated structure at a diffraction grating points of an Al--Cu--Mg--system compound in the electron beam diffraction grating image. The above mentioned streak can be generated efficiently when the alloy essentially consists of 1.5 to 3.5% by weight of Mg, 0.3 to 1.0% by weight of Cu, 0.05 to 0.6% by weight of Si, and the balance of Al and inevitable impurities, and the ratio of Mg/Cu is in the range of 2 to 7. The alloy contains 0.01-0.50% of at least one element selected from the group consisting of Sn, Cd, and In.

Abstract: A method manufacturing an aluminum alloy sheet comprising preparing an aluminum alloy ingot essentially consisting of 1.5 to 3.5% by weight of Mg, 0.3 to 1.0% by weight of Cu, 0.05 to 0.6% by weight of Si, and a balance of Al, in which the ratio of Mg/Cu is in the range of 2 to 7, homogenizing the ingot in one step or in multiple steps, performed at a temperature within a range of 400 to 580.degree. C., preparing an alloy sheet having a desired sheet thickness by subjecting the ingot to a hot rolling and a cold rolling, subjecting the alloy sheet to heat treatment including heating the sheet up to a range of 500.degree. to 580.degree. C. at a heating rate of 3.degree. C./sec. or more, keeping it for 0 to 60 seconds at the temperature reached, and cooling it to 100.degree. C. or less at a looking rate of 2.degree. C./sec. or more, and keeping the alloy sheet at a temperature within a range of 180.degree. to 300.degree. C. for 3 to 60 seconds. Thus, a natural aging-retardated aluminum alloy sheet is obtained.

Abstract: Disclosed is a method manufacturing an aluminum alloy sheet comprising preparing an aluminum alloy ingot essentially consisting of 1.5 to 3.5% by weight of Mg, 0.3% to 1.0% by weight of Cu, 0.05 to 0.35% by weight of Si, 0.03 to 0.5% by weight of Fe, 0.005 to 0.15% by weight of Ti, 0.0002 to 0.05% by weight of B and a balance of Al, in which the ratio of Mg/Cu is in the range of 2 to 7, homogenizing the ingot in one step or in multiple steps, performed at a temperature within the range of 400.degree. to 580.degree. C., preparing an alloy sheet having a desired sheet thickness by subjecting the ingot to a hot rolling and a cold rolling, subjecting the alloy sheet to a heat treatment including heating the sheet up to a range of 500.degree. to 580.degree. C. at a heating rate of 3.degree. C./second or more, keeping it at the temperature reached for 0 to 60 seconds, and cooling at a cooling rate of 2.degree. C.

Abstract: A heat-resistant TiAl alloy having excellent room-temperature fracture toughness, high-temperature oxidation resistance and high-temperature strength is disclosed. Said alloy consists essentially of from 29 to 35 wt. % aluminum, from 0.5 to 20 wt. % nobium, and at least one element selected from the group consisting of from 0.1 to 1.8 wt. % silicon, and from 0.3 to 5.5 wt. % zirconium, the balance being titanium and incidental impurities. Preferably impurities are limited to 0.6 wt.-% oxygen, 0.1 wt.-% nitrogen and 0.5 wt.-% hydrogen.