Abstract: Low-alloy carbon steel for the manufacture of seamless pipes having improved resistance to corrosion, particularly the “sweet corrosion” that occurs in the media rich in CO2, for using in exploration and production of oil and/or natural gas. The steel contains: 1.5-4.0% by weight of Cr, 0.06-0.10% by weight of C, 0.3-0.8% by weight of Mn, not more than 0.005% by weight of S, not more than 0.015% by weight of P, 0.20-0.35% by weight of Si, 0.25-0.35% by weight of Mo, 0.06-0.9% by weight of V, approximately 0.22% by weight of Cu, approximately 0.001% by weight of Nb, approximately 0.028% by weight of Ti, not more than a total value of O of 25 ppm, with the balance being Fe and unavoidable impurities.

Abstract: A heat resistant steel can be produced at a low cost and has an excellent high temperature strength. A high-strength heat-resistant steel is provided which comprises carbon in an amount of 0.06 to 0.15% by weight, silicon in an amount of 1.5% by weight or less, manganese in an amount of 1.5% by weight or less, vanadium in an amount of 0.05 to 0.3% by weight, chromium in an amount of 0.8% by weight or less, molybdenum in an amount of 0.8% by weight or less, at least one selected from niobium, titanium, tantalum, hafnium, and zirconium in an amount of 0.01 to 0.2% by weight, nitrogen in an amount of 20 to 200 ppm, and the balance being iron and unavoidable impurities, and the high-strength heat-resistant steel comprising a bainite structure.

Abstract: An oxidation-resistant coating is described, formed of an alloy containing: about 40 to about 50 atom % aluminum and about 0.5 atom % to about 3 atom % tantalum; with a balance of nickel; cobalt, iron, or combinations thereof. The coating may also include chromium and a precious metal, as well as other components, such as zirconium or molybdenum. A method for applying the oxidation-resistant coating to a substrate is also described. The substrate can be formed of superalloy material, e.g., a turbine engine component. Related articles are also disclosed.

Abstract: In order to produce elements for furnaces, reactors or conduits on the walls of which coke can appear, steels are used with a composition which is adapted to resist coking comprising, by weight, at most 0.25% of C, 1.5% to 5% of Si, 4% to 10% of Cr, 0.5% to 2% of Mo, 0.3% to 1% of Mn, at most 0.030% of S and at most 0.03% of P, the complement to 100% being essentially iron. Novel steel compositions for use in these applications are those which comprise, by weight, at most 0.25% of C, more than 2.5% and up to 5% of Si, 4% to 10% of Cr, 0.5% to 2% of Mo, 0.3% to 1% of Mn, at most 0.03% of S and at most 0.03% of P, the complement to 100% being essentially iron.

Abstract: A porous metal filter possessing enhanced anticorrosive properties is provided including sintered metal particles composed of an alloy composition of iron aluminide having a range in concentration corresponding to Fe3Al to FeAl phases and having a Bubble Point ratio of about 1.6 or less.

Abstract: A high strength, low alloy, heat resistant steel having excellent weldability has an average crystal grain diameter of at most 110 &mgr;m and consists essentially of, by mass %: C: 0.03-0.15%, Si: at most 1%, Mn: at most 2%, P: at most 0.03%, S: at most 0.03%, Ni: at most 0.5%, Cu: at most 0.5%, Cr: 1.8-2.8%, V: 0.1-0.3%, Nb: 0.01-0.08%, Mo: 0.05-0.35%, W: 1.2-1.8%, Ti: 0.001-0.05%, B: 0-0.02%, Al: at most 0.1%, O: at most 0.1%, N: in an amount satisfying the formula [%N]≦[%Ti]+5[%B]+0.004, and a remainder of unavoidable impurities.

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: A heat-resistant steel contains 0.1-3 mass % of Cr and satisfies the following equation: 0.1≦Nb+Mo+V and MX-type complex precipitates formed inside microcrystalline grains contain 30 mass % or more of Mo and 7 mass % or more of Nb. Also provided is a process for producing the alloy steel product involving casting, forging, hot rolling, normalizing, optionally direct quenching, cooling at a predetermined cooling rate, and tempering.

Abstract: An object of the present invention is to provide a corrosion resistant steel excellent in strength and low temperature toughness as well as resistance to corrosion by carbon dioxide and seawater, and most suitable for oil well steel pipes and line pipes for production and transportation of gas, petroleum, etc. used in the field of energy, or a steel for plants, and corrosion resistant oil well steel pipes. The corrosion resistant steel and the corrosion resistant oil well steel pipes comprise, based on weight, up to 0.30% of C, up to 1.0% of Si, 0.2 to 2.0% of Mn, 2.1 to less than 5.0% of Cr, up to 0.03% of P, up to 0.02% of S, up to 0.10% of Al, up to 0.015% of N, optionally containing Cu, Ni, Mo, Ti, Nb and B, and the balance of Fe and unavoidable impurities, and have a martensitic structure as their metallic structure.

Abstract: According to an aspect of the present invention, a piston ring for use in internal combustion engines is provided that is made of matensite-based stainless steel material containing C of not less than 0.4 and not more than 0.8 weight percent, Si of not less than 0.16 and not more than 0.4 weight percent, Mn of not less than 0.1 and not more than 0.4 weight percent, and Cr of not less than 2.0 and not more than 11.0 weight percent, where the steel material of the piston ring has mainly chromium carbide precipitated in the base texture thereof. The steel material of the first compression ring then has a nitriding layer formed thereon. According to another aspect of the present invention, a combination of compression rings, including a first compression ring 1 and a second compression ring 2, for use in internal combustion engines, is provided. The first compression ring 1 is made of martensite-based stainless steel material containing C of not less than 0.16 and not more than 1.

Abstract: A non-heat treated wire or bar steel for springs which is characterized by having in its as-rolled state a tensile strength of 120-150 kgf/mm2 and a bending breakage rate no higher than 15% when tested according to JIS Z-2248 under the condition of r/d=2.8 where r (mm) denotes the inside radius of the bending curvature and d (mm) denotes the diameter of the as-rolled stock.

Abstract: An alloy steel having the capability of retaining high hardness at elevated temperature for a prolonged time is suitable for use as a high speed tool steel. The alloy steel comprises in % by weight: 0.7-1.4 C; less than 1 Mn; less than 0.04 P; up to 0.7 Si; 3-6 Cr; 4-12 Mo; less than 0.5 Co; 0.5-2.25 V; 1-7 W; up to 1.25 Al; at least one of 0.04-2.5 Nb; 0.025-2.5 Zr; 0.08-4.75 Ta and 0.005-0.7 Ti; balance substantially Fe. The alloy may also have an S content of 0.036-0.300; Mn of 0.30-1.35 and may optionally be treated when in a liquid state with up to 0.05 of Mg or Ca.

Abstract: A steel alloy for pipes, sheet metal or sections for manufacturing body reinforcements for motor vehicles, particularly side impact beams or A- and B-column reinforcements, wherein the steel alloy contains in percent by weight 0.1 to 0.17% carbon, 2.0 to 2.8% manganese, 0.4 to 0.8% chromium, 0.1 to 0.35% molybdenum, 0.03 to 0.07% aluminum, 0.002 to 0.003% boron, 0.0001 to 0.005% titanium, 0.08 to 0.012% vanadium, 0.025 to 0.06% niobium, 0.0001 to 0.10 zirconium, 0.01 to 0.05% nitrogen, up to 0.3% silicon, up to 0.025% phosphorus and % 0.010 sulfur, wherein the remainder is iron including impurities caused by smelting, and wherein the sum of the alloy components titanium, vanadium and niobium is between 0.16 and 0.25%.

Abstract: A carburizing steel having the following chemical composition:C: 0.1 to 0.25%,Si: 0.2 to 0.4%,Mn: 0.3 to 0.9%,P: 0.02% or less,S: 0.001 to 0.15%,Cr: 0.5 to 0.9%,Mo: 0.15 to 1%,Al: 0.01 to 0.1%,B: 0.0005 to 0.009%,N: less than 0.006%, andthe balance of Fe and incidental impurities, wherein % is on a weight basis. Also disclosed are a method for the manufacture of the carburizing steel, parts of constant velocity universal joints for drive shafts made of the carburizing steel, as well as a method for the manufacture of such parts. The carburizing steel may further contain Ni: 0.3-4.0%, and one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each. The parts of constant velocity universal joints for drive shafts are manufactured using the carburizing steel of the present invention as a material. When they are carburized and quenched, they exhibit a surface hardness (Hv) of 650-800, core hardness (Hv) of 250-450, and carburized case depth of 0.2-1.2 mm.

Abstract: This invention relates to high-Cr precision casting materials containing carbon, silicon, manganese, chromium, nickel, vanadium, niobium, nitrogen, molybdenum, tungsten, cobalt and optionally boron in specific weight proportions, the balance being iron and incidental impurities, as well as turbine blades made by a precision casting process using these materials. Thus, the present invention provides high-Cr precision casting materials which are capable of precision casting and, moreover, have excellent high-temperature strength, as well as inexpensive and highly reliable turbine blades made by using these casting materials and such turbine blades also having lighter weight.

Abstract: A powder-metallurgy produced high-speed steel article having a combination of high hardness and wear resistance, particularly at elevated temperatures. This combination of properties is achieved by the combination of W, Mo, V, and Co. The article is particularly suitable for use in the manufacture of gear cutting tools, such as hobs, and surface coatings.

Abstract: A cast cold tool is obtained through the steps of forming a casting by founding a molten steel consisting by weight percentage of 0.5 to 0.8% of C, not more than 1.0% of Si, 0.25 to 1.50% of Mn, 4.0 to 8.0% of Cr, 1.0 to 5.0% of Mo, one or both of 0.2 to 1.0% of V and 0.2 to 2.0% of Nb, opptionally not more than 2.5% of W, not more than 2.5% of Ni, and the balance being Fe plus incidental impurities, subjecting the casting to solid solution treatment to decrease primary carbides precipitated in the casting to not more than 1%, preferably to extinguish completely, and subjecting the solid-solution treated casting to quenching and tempering treatment to give predetermined toughness and hardness to the casting.

Abstract: A steel having excellent HAZ toughness can be used for ships, buildings, pressure containers, linepipes, and so forth. The steel is of a Ti--Mg--O system steel containing at least 40 pcs/mm.sup.2 of oxide and composite oxide particles of Ti and Mg having a size of 0.001 to 5.0 .mu.m. A steel having excellent HAZ toughness can be produced, and the safety of structures using this steel can be remarkably improved.

Abstract: Disclosed is a piston ring material excellent in workability, which consists essentially of, by weight, 0.4 to 1.0% of C, 5.0 to 25.0% of Cr, at least one of not more than 0.25% Si and not more than 0.30% Mn, and balance of Fe and impurities. The material may optionally contain one or more elements of Mo, W, V and Nb in place of a part of Fe.

Abstract: The invention relates to a steel and to a process for the manufacture of a steel component formed by cold plastic deformation.

Abstract: High strength steel is produced by a first rolling of a steel composition, reheated above 1100.degree. C., above the austenite recrystallization, a second rolling below the austenite recrystallization temperature, water cooling from above Ar.sub.3 to less than 400.degree. C. and followed by tempering below the Ac.sub.1 transformation point.

Abstract: The present invention has an object to provide a steel for a chimney or a gas duct, which is excellent in pitting resistance and rust adhesion in a corrosive environment caused by combustion waste gas in a plant in which the combustion of natural gas occurs. Pitting resistance and rust adhesion are remarkably improved in the steel of the present invention which steel is prepared by using a 5% Cr steel as the base, while reducing an impurity sulfur to not more than 0.010 wt. %, adding titanium within a range of 0.005 to 0.05 wt. %, and further adding nickel alone within a range of 1.0 to 2.5 wt. %, or adding molybdenum alone within a range of 0.10 to 1.0 wt. %, or adding in combination therewith trace amount of copper or molybdenum within a range of 0.10 to 1.0 wt. %.

Abstract: A bearing steel is provided which can satisfy bearing property requirements and, at the same time, is improved in mechanical properties, such as impact, crushing, and transverse properties, while reducing the cost of materials and the cost of heat treatment for the production of a bearing. The bearing steel comprises by weight C: 0.70 to 0.93%, Si: 0.15 to 0.50%, Mn: 0.50 to 1.10%, Cr: 0.30 to 0.65%, and N: 0.005 to 0.02% with the balance consisting of Fe and unavoidable impurities and 0.4.ltoreq.Cr/C.ltoreq.0.7, the steel further comprising at least one of (1) Al: 0.01 to 0.1% with Al.times.N.gtoreq.0.00015 and (2) Nb: 0.02 to 0.1%. A rolling bearing produced from the bearing steel is also provided.

Abstract: A wire for gas metal arc welding containing 0.01 to 0.06 wt % of C, 0.10 to 0.60 wt % of Si, 0.9 to 3.1 wt % of Mn, 0.7 to 2.0 wt % of Cr, 0.005 to 0.06% of Ti, not greater than 0.08 wt % of Al and if necessary, 0.05 to 0.30 wt % of Cu, and the balance of Fe and unavoidable impurities. This wire improves the selective corrosion resistance and the low temperature toughness of the resulting weld metal, and is particularly suitable for circumferential welding of line pipes for transporting CO.sub.2 -containing petroleum, natural gases or CO.sub.2.

Abstract: The present invention relates to a steel having excellent corrosion resistance and workability and more particularly to a steel having excellent corrosion resistance and workability in an exhaust system of internal combustion engines in, for example, internal combustion engines in automobiles and ships. A steel having excellent corrosion resistance and a steel having excellent corrosion resistance and workability, characterized by comprising Si: not less than 0.01 to less than 1.2%, Mn: 0.1 to 1.5%, Cr: 2.5 to 9.9%, and Al: more than 3.0 to 8.0%, and, reduced to, C: not more than 0.02%, P: not more than 0.03%, S: not more than 0.01%, and N: not more than 0.02%, and further comprising 0.01 to 0.5% in total of Nb, V, Ti, Zr, Ta, and Hf so as to meet a particular conditional formula, or further comprising at least one member selected from Cu, Mo, Sb, Ni, W, rare earth elements, and Ca, with the balance consisting of Fe and unavoidable impurities.

Abstract: The properties of conventional steels for rails, check rails and railroad rolling components can be improved by small amounts of tellurium. This applies particularly to the wear resistance and the mechanical properties in the transverse direction and at oxygen contents of less than 0.0015% and sulfur contents up to 0.007%.

Abstract: The present invention is intended to provide a high carbon bearing steel, for bearing parts, excellent in rolling fatigue characteristics. A high carbon bearing steel having a long life comprising 0.70 to 1.20% of C, 0.15 to 1.70% of Si, 0.15 to 1.20% of Mn, 0.50 to 2.00% of Cr, 0.05 to 1.50% of Mo, 0.001 to 0.03% of S, 0.010 to 0.05% of Al, 0.003 to 0.015% of N, 0.0005 to 0.0300% of total Mg, up to 0.025% of P, up to 0.0040% of Ti, up to 0.0015% of total oxygen, one or at least two elements selected from V, Nb and Ni in specific amounts, and having a number ratio of Mg oxides contained therein of at least 0.8.

Abstract: Low alloy steel for the manufacture of molds for plastics or for rubber, the chemical composition of which comprises, by weight, 0.24% to 0.35% of carbon, 1% to 2.5% of manganese, 0.3% to 2.5% of chromium, 0.1% to 0.8% of molybdenum plus tungsten divided by 2, up to 2.5% of nickel, 0% to 0.3% of vanadium, less than 0.5% of silicon, 0.002% to 0.005% of boron, 0.005% to 0.1% of aluminum, 0% to 0.1% of titanium and less than 0.02% of phosphorus. The chemical composition must furthermore satisfy the relationship:U=409(% C)+19.3[% Cr+% Mo+% W/2+% V]+29.4(% Si)+10(% Mn)+7.2(% Ni)<200and the relationship:R=3.82(% C)+9.79(% Si)+3.34(% Mn)+11.94(% P)+2.39(% Ni)+1.43(% Cr)+1.43(% Mo+% W/2)<11.

Abstract: Alloy steel powders capable of obtaining high strength in a sintered state and having excellent compacting compressibility and methods of manufacturing a sintered body. The alloy steel powder comprises, by wt %, about 0.5-2% of Cr, not greater than about 0.08% of Mn, about 0.1-0.6% of Mo, about 0.05-0.5% of V, not greater than about 0.015 of S, not greater than about 0.2% of O, and the balance being Fe and incidental impurities. The alloy steel powder is compacted and sintered at a temperature of about 1100.degree.-1300.degree. C. and then cooled at a cooling rate no higher than about 1.degree. C./s in a temperature range of from about 800.degree. C. to 400.degree. C. The alloy steel powder can contain Nb and/or Ti and one or more of Co, W and B. Additionally, Ni powder and/or Cu powder may be adhered and dispersed onto the surface of the alloy steel powder.

Abstract: A deep hardening boron steel has a composition comprising, by weight, about 0.23% to 0.37% carbon, about 0.40% to 1.20% manganese, about 0.50% to 2.00% silicon, about 0.25% to 2.00% chromium, about 0.20% to 0.80% molybdenum, from 0.05% to 0.25% vanadium, from 0.03% to 0.15% titanium, from 0.015% to 0.050% aluminum, from 0.0008% to 0.009% boron, and 0.005% to 0.013% nitrogen. Also, the composition preferably contains less than about 0.025% each of phosphorus and sulfur. After quenching and tempering, articles made from this material are substantially free of aluminum nitrides, have a fine martensitic grain structure, have a distribution of nanometer size background nitride, carbonitride, and carbide precipitates, and a combination of high hardness and fracture toughness.The deep hardening steel article embodying the present invention is particularly useful for ground engaging tools that are subject breakage and wear, often at high temperature.

Abstract: A low-Cr ferritic steel with improved toughness as well as creep strength is disclosed, which consists essentially of, by weight %:C: 0.03-0.12%, Si: 0.70% or less, Mn: 0.10-1.50%,Ni: 2.0% or less, Cr: 1.50-3.50%, W: 1.0-3.0%,V: 0.10-0.35%, Nb: 0.01-0.10%,B: 0.00010-0.020%, N: 0.005% or less,Al: 0.005% or less,Ti: not less than 0.001% but less than 0.05%,Cu: 0.10-2.50%,at least one of La, Ce, Y, Ca, Zr, Ta each in an amount of 0-0.20%, and Mg in an amount of 0-0.05%,Mo in an amount of 0-0.40%, anda balance of Fe and incidental impurities including P: not more than 0.030% and S: not more than 0.015%.

Abstract: An abrasion-resistant steel consists essentially of 0.05 to 0.45 wt. % C, 0.1 to 1 wt. % Si, 0.1 to 2 wt. % Mn, 0.05 to 2 wt. % Nb and the balance being Fe and inevitable impurities, the steel includes at least 200 of precipitates of 15 .mu.m or more in particle size per 1 mm.sup.2 and the precipitates contains Nb.In addition to the above basic elements, at least one element selected from the group consisting of 0.1 to 2 wt. % Cu, 0.1 to 10 wt. % Ni, 0.1 to 3 wt. % Cr, 0.1 to 3 wt. % Mo and 0.0003 to 0.01 wt. % B or at least one element selected from the group consisting of 0.003 to 0.05 wt. % Ti and 0.01 to 1 wt. % V is added to steel.

Abstract: A low-alloy steel consists essentially, on a weight basis, of: C: 0.03-0.12%, Si: at most 0.7%, Mn: 0.1-1.5%, Ni: at most 0.8%, P: at most 0.03%, S: at most 0.015%, Cr: 1.5-3.5%, W: 1-3%, V: 0.1-0.35%, Nb: 0.01-0.1%, B: 0.0001-0.02%, N: less than 0.005%, Al: less than 0.005%, Ti: 0.001-0.1%, optionally one or more elements selected from the group consisting of: La, Ce, Y, Ca, Zr, and Ta: 0.01-0.2%, Mg: 0.0005-0.05%, and Mo: 0.01-0.4%, and a balance of Fe and incidental impurities, wherein the Ti and Ni contents satisfy the following inequality:0.080.gtoreq.Ti(%)-(48/14).times.N(%).gtoreq.0.003.The steel has improved creep strength at high temperatures and improved toughness. It can be substituted for expensive austenitic stainless steels or high-Cr ferritic steels.

Abstract: A modified H-13 hot work die steel in which impact toughness and thermal fatigue resistance is greatly improved. The steel consists of in weight %:______________________________________ Carbon (C): 0.34-0.40, Manganese (Mn): 0.25-0.45, Silicon (Si): 0.85-1.15, Chromium (Cr): 5.00-5.40, Nickel (Ni): 0.30 max, Molybdenum (Mo): 1.20-1.50, Vanadium (V): 0.31-0.52, Niobium (Nb): 0.02-0.09, Iron (Fe) and Incidental impurities: Balance ______________________________________The steel also preferably includes about 0.01-0.20 weight % titanium (Ti) and is preferably subjected to premium quality treatment, including remelting and homogenization, either thermal or mechanical (by hot working).

Abstract: A flat spring hose clamp having an improved resistance to brittle fracture and a method for manufacturing the same are disclosed, the hose clamp being made of a steel having a steel composition consisting essentially of, by weight %:C:0.30-0.70%,Si: 0.70% or less,Mn: 0.05-1.00%,P: 0.030% or less,S: 0.020% or less,Cr: 0.50-2.00%,Mo: 0.10-0.50%,Nb: 0.005-0.100%,sol. Al: 0.10% or less,N: more than 0.0020%, but not more than 0.015%,Ti: 0-0.10% and/or B: 0-0.0020%,and a balance of Fe and incidental impurities, and the steel possessing a uniform bainite structure.

Abstract: Disclosed is a high strength spring steel consisting of, in weight percentage, 0.50 to 0.70% C, 1.00 to 2.50% Si, 0.30 to 1.20% Mn, 0.80 to less than 1.20% Cr, 0.05 to 0.3% Mo, 0.05 to 0.30% V, 0.01 to 0.30% Nb, 0.005 to 0.100% Al and the balance being Fe and unavoidable impurities. The steel of the present invention has a high hardness coupled with high toughness and is very useful, especially for springs used in suspension devices or other various industrial machines.

Abstract: A deep hardening steel has a composition comprising, by weight, about 0.26% to 0.37% carbon, about 0.5% to 1.0% manganese, about 1.0% to 3.0% silicon, about 1.5% to 2.5% chromium, about 0.3% to 1.0% molybdenum, from 0.05% to 0.2% vanadium, from 0.03% to 0.1% titanium, from 0.01% to 0.03% aluminum and at least 0.005% nitrogen. Also, the composition preferably contains less than about 0.025% each of phosphorus and sulfur. After quenching and tempering, articles made of this material are substantially free of aluminum nitrides, have a fine grained microstructure, and a combination of high hardness and fracture toughness.The deep hardening steel article embodying the present invention is particularly useful for ground engaging tools that are subject to breakage and abrasive wear at high temperature.

Abstract: A chromium heat-resistant steel excellent in toughness and having a high cracking resistance and a high creep strength when said steel is utilized to form a welded joint, said steel consisting essentially of:______________________________________ carbon: from 0.04 to 0.09 wt. %, silicon: from 0.01 to 0.50 wt. %, manganese: from 0.25 to 1.50 wt. %, chromium: from 7.0 to 9.2 wt. %, molybdenum: from 0.50 to 1.50 wt. %, soluble aluminum: from 0.005 to 0.060 wt. %, nitrogen: from 0.001 to 0.060 wt. %, ______________________________________where, the total amount of nitrogen and carbon being up to 0.13 wt. %, at least one element selected from the group consisting of: ______________________________________ vanadium: from 0.01 to 0.30 wt. %, and niobium: from 0.005 to 0.200 wt. %, ______________________________________where, the total amount of vanadium and 1.5 times niobium being up to 0.30 wt. %, and the balance being iron and incidental impurities; and the amount of ferrite as represented by the ferrite number (.

Abstract: A rolling-part steel and a rolling part employing same are disclosed. The steel includes: C; 0.1 to 0.7 wt. %, Si; below or equal to 0.04 wt. %; Mn; below or equal to 1.0 wt. %, Cr; 0.2 to 1.0 wt. %, S; below or equal to 0.003 wt. %; P; below or equal to 0.025 wt. %, O; below or equal to 0.0015 wt. %, the reminder Fe, and a necessary impurity. The steel has a good plastic-workability such that the rolling part can be produced only by plastic working. The steel also has a good hardenability.

Abstract: Described herein is high strength steels used for bolts containing as alloy elements:0.30%.ltoreq.C.ltoreq.0.50%,Si<0.10%,0.50%.ltoreq.Mn.ltoreq.0.70%,P.ltoreq.0.01%,S.ltoreq.0.01%,0.30%.ltoreq.Cr.ltoreq.1.05%,0.50%.ltoreq.Mo.ltoreq.1.05%,0.01%.ltoreq.al.ltoreq.0.05%,0.0020%.ltoreq.Ti.ltoreq.0.050%, and0.002%.ltoreq.N.ltoreq.0.010%,the elements Si, Mn, P, S, Mo, Al, Ti and N satisfying the relation as follows0.05%.ltoreq.Mo-45P-11S.ltoreq.0.85%7.5Si+1.7Mn.ltoreq.1.85%, and0.020%.ltoreq.10Ti+Al-6N.ltoreq.0.50%;and the balance of Fe and inevitable impurities.The high strength steels used for bolts may optionally contain at least one of Ni and V in the range of0.2%.ltoreq.Ni.ltoreq.1.5% and 0.05%.ltoreq.V.ltoreq.0.15%, respectively.

Abstract: A steel from which rolls for a cold rolling mill are made and which gives to the rolls very excellent wear resistance in addition to thermal shock and spalling resistances and various mechanical characteristics is provided. Said steel comprises:C : 0.70 to 1.50 wt %Si: 0.15 to 1.00 wt %Mn: 0.15 to 1.50 wt %Cr: 2.50 to 10.00 wt %Mo: 1.00 wt % or lessV : 1.00 wt % or lessNi: 1.00 wt % or lessTi: 0.04 to 0.30 wt %with the balance being Fe and inevitable impurities.

Abstract: A low-alloy steel suitable for use in generator rotors and having a combination of good strength and impact energy with a high magnetic permeability is disclosed. The low-alloy steels are comprised of in weight percent; about 3.5 to 5.25 percent nickel, about 0.75 to 2.0, percent chromium, about 0.3 to 0.8 percent molybdenum, about 0.05 to 0.15 percent vanadium, about 0.1 to 0.28 percent carbon, about 0.03 to 0.1 percent niobium or titanium, and the balance substantially iron, wherein nickel, chromium, and carbon additions are balanced.

Abstract: A high-strength high-Cr ferritic, heat-resistant steel exhibiting improved high-temperature, long-term creep strength and a process for producing the same are disclosed. The steel consists essentially of, by weight %:______________________________________ C: not more than 0.2%, Si: not more than 1.0%, Mn: 0.1-1.5%, P: not more than 0.03%, S: not more than 0.03%, Ni: not more than 1.0%, Cr: 5.0-15%, Mo: 0.02-3.0%, W: not more than 4.0%, sol. Al: 0.05-0.04%, N: not more than 0.07%, ______________________________________at least one of V: 0.01-0.4% and Nb: 0.01-0.3%, B: 0-0.02%,at least one of Ca, Ti, Zr, Y, La, and Ce: 0-0.2%, andthe balance Fe and incidental impurities,A.sub.cl point defined by Formula (1) below being 820 or higher.

Abstract: Air-hardenable steels of duplex bainite/martensite microstructure consisting essentially of 0.10 to 0.7% C, 0.1 to 2% Si, 2.1 to 3.5% Mn, 0.0005 to 0.005% B, up to 3.5% Cr and preferably containing Cr in amount of at least 0.1%, balance Fe except for incidental impurities. Optional elements are up to 1.5% W, 1.0% Mo, 0.15% V, 0.2% S, 0.1% Ca, 0.1% Pb, 0.1% Ti and 0.2% total rare earths. At least 1.0% Cr is especially preferred and if below such amount, total Mn and Si is at least 3% and in such case, if C is under 0.47%, at least 0.6% Si is present. The steels are hardenable to R.sub.c 20 to R.sub.c 58 and have a hardenable diameter in the range between 35 mm and 80 to 100 mm by air-cooling only, together with good strength, toughness and fatigue- and wear-resistance.

Abstract: A brake disc material which does not crack under a great braking action, such as in a large-sized truck, consisting of 0.03 percent to 1 percent of carbon, 1.2 percent to 20 percent of chromium, and 0.1 percent to 1 percent of molybdenum, the balance being essentially iron.

Abstract: Low alloy steels for use in pressure vessel comprising on the weight % basis:C: from 0.05% to 0.30%,Si: less than 0.10%,Mn: from 0.3% to 1.5%,Ni: from inevitably incorporated content to 0.55%,Cr: from 1.5% to 5.5%,Mo: from 0.25% to 1.5%,V: in excess of 0.10% and less than 0.6%, andthe balance of iron and inevitably incorporated impurities.The steels are excellent in hardenability, the hot strength, toughness weldability and hydrogen attack and embrittlement resistance, as well as show excellent toughness after the use in the temper brittle temperature region.

Abstract: A high-strength, heat-resisting ferritic steel pipe or tube for boiler use containing 0.03 to 0.15% C, 0.1 to 1.5% Mn, 8 to 13% Cr, 1.8 to 3.0% W, 0.05 to 0.30% V, 0.02 to 0.12% Nb, 0.02 to 0.05% N, 0.02 to 0.4% Mo, and up to 0.25% Si. This pipe or tube has an improved high-temperature creep rupture strength and an excellent weldability and toughness.

Abstract: A steel composition particularly suitable for the manufacture of electric resistance welded pipes for use in most hostile environments and able to display excellent sour resistance and high toughness. The aluminum content of the steel composition is reduced to not more than 0.005%, while from 0.006 to 0.2% in total of one or both of titanium and zirconium is used instead for steel containing 0.0005 to 0.008% Ca. The steel, apart from iron and unavoidable impurities further contains:0.01 to 0.35% C0.02 to 0.5% Si0.1 to 1.8% Mnnot more than 0.015% P, andnot more than 0.003% SCu, Ni, Cr, Mo, Nb and V may be added in appropriate amounts to enhance the steel performance.

Abstract: A high strength bolt made of a steel having a specifically defined chemical composition, i.e., by weight C: 0.30-0.50%; Si: not more than 0.15%; Mn: not more than 0.40%; Cr: 0.30-1.50%; Mo: 0.10-0.70%; and V: 0.15-0.40%, the balance being Fe and inevitable impurities such as P, S, etc. in trace amount. The manufacturing method therefor is featured in a strictly controlled heat treatment in respect to the temperature range such as: hardening by quenching from 940.degree..+-.10.degree. C. and tempering 575.degree..+-.25.degree. C.

Abstract: Isotropic tool steel consisting essentially of necessary elements as tool steel, less than 0.005 weight % of S and less than 30 ppm of O, the balance being substantially Fe. The necessary elements are, by weight, 0.10-0.70% of C, 2.00% or less of Si, 2.00% or less of Mn, 7.00% or less of Cr, 0.20-12.00% of W and/or Mo alone or in combination (1/2W+Mo), 3.00% or less of V. They may further include at least one of 4.00% or less of Ni, 6.50% or less of Co and 0.20% or less of N. The isotropic tool steel has cleanliness with respect to non-metallic inclusions defined by JIS G 0555 of dA60.times.400.ltoreq.0.010% and d(B+C)60.times.400.ltoreq.0.020%, and a ratio of transverse direction toughness to longitudinal direction toughness of more than 0.70. Since it is highly resistant to the generation and propagation of cracks and fracture, dies for hot working made therefrom can enjoy a long life.