Abstract: A steel material which is suitable for hot press working or hot three-dimensional bending and direct quench and which can be used to manufacture a high-strength formed article with sufficient quench hardening even by short time heating at a low temperature has a chemical composition comprising, in mass percent, C: 0.05-0.35%, Si: at most 0.5%, Mn: 0.5-2.5%, P: at most 0.03%, S: at most 0.01%, sol. Al: at most 0.1%, N: at most 0.01%, and optionally at least one element selected from the group consisting of B: 0.0001-0.005%, Ti: 0.01-0.1%, Cr: 0.18-0.5%, Nb: 0.03-0.1%, Ni: 0.18-1.0%, and Mo: 0.03-0.5% and has a steel structure in which the spheroidization ratio of carbides is 0.60-0.90.

Abstract: A shell type outer ring 2 of a shell type needle roller bearing 1 is formed by a pressing combined with an ironing step, and the lubricating conditions in this ironing step on the outer-diameter ironed surface, which becomes the outer-diameter surface of the outer ring 2, are in a substantially fluid lubricating state so as to restrict the circumferential surface roughness of the inner-diameter surface, the inner-diameter roundness, and the amount of uneven thickness of the tubular portion to predetermined value ranges, thereby prolonging the life of the shell type needle roller bearing and lowering the acoustic level during use.

Abstract: There are provided a steel for deep drawing, and a method for manufacturing the steel and a high pressure container. The steel for deep drawing includes, by weight: C: 0.25 to 0.40%, Si: 0.15 to 0.40%, Mn: 0.4 to 1.0%, Al: 0.001 to 0.05%, Cr: 0.8 to 1.2%, Mo: 0.15 to 0.8%, Ni: 1.0% or less, P: 0.015% or less, S: 0.015% or less, Ca: 0.0005 to 0.002%, Ti: 0.005 to 0.025%, B: 0.0005 to 0.0020% and the balance of Fe and inevitable impurities, wherein a microstructure of the steel has a triphase structure of ferrite, bainite and martensite. The steel for deep drawing may be useful to further improve the strength without the deterioration of the toughness by adding a trace of Ti and B, compared to the conventional steels having a strength of approximately 1100 MPa.

Abstract: It is an object of the present invention to provide a high strength cold-rolled steel sheet, which has superior bake hardenability, aging resistance at room temperature and secondary work embrittlement resistance, and a method for manufacturing the same. The steel sheet has a grain size of ASTM No. of 9 or more after annealing, a BH of 30 MPa or more, an AI of 30 MPa or less, and a tensile strength of 340˜390 MPa through appropriate control of solute elements in steel by addition of a small amount of Ti, addition of Al and Mo, and control of manufacturing conditions, and refinement of crystal grains after annealing. The cold-rolled steel sheet and the galvannealed steel sheet produced using the cold-rolled steel sheet have the superior bake hardenability, aging resistance at room temperature, and secondary work embrittlement resistance.

Abstract: A method for manufacturing a fine spheroidized steel sheet having an excellent heat treatment characteristic, the method including: i) manufacturing a high carbon slab that is formed of 0.3 to 1.0 wt % C, 0.1 to 1.2 wt % Mn, 0 to 0.4 wt % Si, 0.01 to 0.1 wt % Al, 0 to 0.01 wt % S, and balance Fe and an inevitably added impurity as residuals; ii) reheating the slab to a temperature of Ar3 transformation point or more; iii) roughing rolling the slab, and manufacturing a thin plate by performing finish rolling in an austenite region; iv) cooling the thin plate at a cooling speed of 50 to 300° C./sec; v) finishing the cooling of the thin plate at a temperature region of 400 to 650° C. and maintaining the temperature; vi) winding the thin plate at a temperature region of 450 to 700° C.; vii) performing cold rolling at a reduction ratio of 30% or more; and viii) spheroidizing annealing the cold rolled thin plate.

Abstract: A steel part having a long rolling contact fatigue life and capable of further increasing the life of a bearing under severer using condition than usual conditions. The steel part includes steel having a composition containing 0.7% by mass to 1.1% by mass of C, 0.5% by mass to 2.0% by mass of Si, 0.4% by mass to 2.5% by mass of Mn, 1.6% by mass to 5.0% by mass of Cr, 0.1% by mass to less than 0.5% by mass of Mo, 0.010% by mass to 0.050% by mass of Al, less than 0.0015% by mass of Sb as an impurity, and the balance composed of Fe and inevitable impurities, the steel being hardened and tempered. In the steel structure of a portion from the surface to a depth of 5 mm, residual cementite has a grain diameter of 0.05 to 1.5 ?m, prior austenite has a grain diameter of 30 ?m or less, and the ratio by volume of the residual austenite is less than 25%.

Abstract: An ultra soft high carbon hot-rolled steel sheet has excellent workability. The steel sheet is a high carbon hot-rolled steel sheet containing 0.2 to 0.7% C, and has a structure in which mean grain size of ferrite is 20 ?m or larger, the volume percentage of ferrite grains having 10 ?m or smaller size is 20% or less, mean diameter of carbide is in a range from 0.10 ?m to smaller than 2.0 ?m, the percentage of carbide grains having 5 or more of aspect ratio is 15% or less, and the contact ratio of carbide is 20% or less.

Abstract: The present invention provides an ultra soft high carbon hot-rolled steel sheet. The ultra soft high carbon hot-rolled steel sheet contains 0.2% to 0.7% of C, 0.01% to 1.0% of Si, 0.1% to 1.0% of Mn, 0.03% or less of P, 0.035% or less of S, 0.08% or less of Al, 0.01% or less of N, and the balance being Fe and incidental impurities and further contains 0.0010% to 0.0050% of B and 0.05% to 0.30% of Cr in some cases. In the texture of the steel sheet, an average ferrite grain diameter is 20 ?m or more, a volume ratio of ferrite grains having a grain diameter of 10 ?m or more is 80% or more, and an average carbide grain diameter is in the range of 0.10 to less than 2.0 ?m. In addition, the steel sheet is manufactured by the steps, after rough rolling, performing finish rolling at a reduction ratio of 10% or more and at a finish temperature of (Ar3?20° C.) or more in a final pass, then performing first cooling within 2 seconds after the finish rolling to a cooling stop temperature of 600° C.

Abstract: Provided are a steel having excellent rolling contact fatigue life and the manufacturing method thereof. The steel consists essentially of 0.7 to 1.1% C, 0.2 to 2.0% Si, 0.4 to 2.5% Mn, 1.6 to 4.0% Cr, 0.1% or more and less than 0.5% Mo, 0.010 to 0.050% Al, bymass, and balance of Fe and inevitable impurities, is treated by quenching and tempering, has residual cementite grain sizes ranging from 0.05 to 1.5 ?m, and has prior-austenite grain sizes of 30 ?m or smaller. When the steel is used to bearing steel, the bearing life extends even under service in more severe environments.

Abstract: Steel tubes for bearing element parts according to the present invention, wherein the specific compositions are limited and an accumulation intensity of {211} face along with an impact property at ambient temperature in the longitudinal direction of steel tube are specified, can be provided as a source material for bearing element parts, which have excellent machinability and fatigue life in rolling contact, being incorporated without adding a free-cutting element specifically nor without reducing productivity since the spheroidizing for the same annealing duration with that of conventional spheroidizing treatment can be applied. Accordingly, by applying a manufacturing method or a cutting-machining method according to the present invention, bearing element parts such as races, rollers and shafts can be produced with less cost and efficiently.

Abstract: A pushing block for the CVT belt has a hyper-eutectoid structure overall and exhibiting a structure in which spheroidal cementite having an area percentage of 0.4% or more are dispersed in a matrix of a martensite.

Abstract: A process for making an iron-based casting alloy is performed by combining an iron-carbon-chromium system with primary carbides of vanadium, niobium, titanium, or combinations thereof without eutectic carbides of vanadium, niobium and titanium. Eutectic chromium carbides (M7C3) are also formed without primary chromium carbides. Proeutectic austenite can also be formed in the alloy.

Abstract: The continuous annealing furnace has two or more treatment chambers sequentially connected with each other and respectively filled with a gas atmosphere differing in carburizing property, which includes a carburizing chamber wherein roller members to be treated are carburized at 750° C. to 820° C., a slow cooling chamber wherein the roller members are cooled at said temperature or less of the carburizing chamber, an intermediate chamber including atmosphere gas blocking doors that can open/close an exit of the carburizing chamber and an entrance of the slow cooling chamber independently, and transferring means, and each chambers is filled to satisfy a relationship of K1−K2≧2 where K1 represents a partial pressure ratio between CO and CO2 in an atmosphere within the carburizing chamber and K2 represents a partial pressure ratio between CO and CO2 in an atmosphere within the slow cooling chamber.

Abstract: A composite doctor blade comprises a steel support band configured with a width and thickness suitable for mounting in a blade holder, with tensile and yield strengths suitable for a selected doctoring application. A wear resistant strip of high speed steel is integrally joined to an edge of the support band. The wear resistant strip has tensile and yield strengths higher than those of the support band, and has a hardness of between about 55 to 75 Rc.

Abstract: A machine structural steel bar or wire having a softening degree of at least that of the conventional spheroidization-annealed steel material, excellent hardenability, and improved cold workability, comprising 0.1 to 0.5 wt % of C, 0.01 to 0.15 wt % of Si, 0.2 to 1.7 wt % of Mn, 0.0005 to 0.05 wt % of Al, 0.005 to 0.07 wt % of Ti, 0.0003 to 0.007 wt % of B, 0.002 to 0.02 wt % of N and the balance of Fe and unavoidable impurities, the unavoidable impurities including up to 0.02 wt % of P and up to 0.003 wt % of O, and having a microstructure comprising ferrite and spheroidal carbides, the ferritic grain size number according to JIS G0522 of the ferrite being at least No. 8 and the number of the spheroidal carbides per unit area mm2 being up to 1.5×106×C wt %.

Abstract: A composite doctor blade comprises a steel support band configured with a width and thickness suitable for mounting in a blade holder, with tensile and yield strengths suitable for a selected doctoring application. A wear resistant strip of high speed steel is integrally joined to an edge of the support band. The wear resistant strip has tensile and yield strengths higher than those of the support band, and has a hardness of between about 55 to 65 Rc.

Abstract: Steel for the manufacture of a component for bearings, the chemical composition of which comprises, by weight: 0.6%≦C≦1.5%; 0.4%≦Mn≦1.5%; 0.75%≦Si≦2.5%, 0.2%≦Cr≦2%; 0%≦Ni≦0.5%; 0%≦Mo≦0.2%; 0%≦Al≦0.05%; S≦0.04%; the balance being iron and impurities resulting from smelting and the composition furthermore satisfying the relationships: Mn≦0.75+0.55×Si and Mn≦2.5−0.8×Si. Process for the manufacture of a bearing component.

Abstract: Steel for the manufacture of a component for bearings, the chemical composition of which comprises, by weight: 0.6%≦C≦1.5%; 0.4%≦Mn≦1.5%; 0.75%≦Si≦2.5%; 0.2%≦Cr≦2%; 0%≦Ni≦0.5%; 0%≦Mo≦0.2%; 0%<Al≦0.05%; S≦0.04%; the balance being iron and impurities resulting from smelting and the composition furthermore satisfying the relationships: Mn≦0.75+0.55×Si and Mn≦2.5−0.8×Si. Process for the manufacture of a bearing component.

Abstract: A medium-carbon steel is provided having a dispersed fine spherical graphite structure, having high mechanical strength, good processability, and good machinability, and having fine ZrC functioning as nucleation sites for graphite. The medium-carbon steel having a dispersed fine spherical graphite structure is manufactured by providing a composition containing 0.1 to 1.5% Si, 1.0% or less C, and 0.01 to 0.5% Zr. After the composition or a material of the composition (ingot) has been hot-rolled, or after the hot-rolled steel has been heat-treated at 750 to 1300° C. for 0.5 to 10 hours (solution heat treatment) after hot-rolling, or after the hot-rolled and heat-treated steel has further been water-quenched to deposit fine ZrC particles in the matrix, the steel is subjected to graphitization treatment by heat-treating at a temperature of 740° C. or below for 0.5 to 100 hours to grow graphite using ZrC as the nucleation site.

Abstract: A thixocast casting material is formed of an Fe--C--Si based alloy in which an angle endothermic section due to the melting of a eutectic crystal exists in a latent heat distribution curve and has a eutectic crystal amount Ec in a range of 10% by weight <Ec<50% by weight. This composition comprises 1.8% by weight .ltoreq.C.ltoreq.2.5% by weight of carbon, 1.4% by weight .ltoreq.Si.ltoreq.3% by weight of silicon and a balance of Fe including inevitable impurities.

Abstract: A flexible screw for conveyors, which is made of a flexible rod and a polymer-coated cord helically wound on the rod, the cord being made of a core and a polymer layer formed on the core, and the core being a fiber bundle having a specific amount of buckling of not more than 0.3%. When the screw is used for transporting containers, it can adapt itself to a drastic change in the surrounding temperature and can endure a great tension caused by the transport of heavy containers, since winding pitch of the cord is not easily widened and the disturbance of the pitch can be prevented.