Provided is an abrasion-resistant steel including a predetermined chemical composition, in which content (mass %) of Mo and B satisfy MoB>0.0010, a mass fraction of Mo.sub.2FeB.sub.2 is from 0.0010 to 0.10%, an area ratio of martensite in a central portion in a thickness direction is 70% or more, Ceq obtained by the following (Formula 1) is 0.80% or less, and a plate thickness exceeds 50 mm;

Ceq=C+Mn/6+(Cu+Ni)/15+(Cr+Mo+V)/5(Formula 1) wherein, in (Formula 1), C, Mn, Cu, Ni, Cr, Mo, and V are contents (mass %) of each element.

An iron-based alloy includes, in weight percent, carbon from about 1 to about 2 percent; manganese from about 0.1 to about 1 percent; silicon from about 0.1 to about 2.5 percent; chromium from about 11 to about 19 percent; nickel up to about 8 percent; vanadium from about 0.8 to about 5 percent; molybdenum from about 11 to about 19 percent; tungsten up to about 0.5 percent; niobium from about 1 to about 4 percent; cobalt up to about 5.5 percent; boron up to about 0.5 percent; nitrogen up to about 0.5 percent, copper up to about 1.5 percent, sulfur up to about 0.3 percent, phosphorus up to about 0.3 percent, up to about 5 percent total of tantalum, titanium, hafnium and zirconium; iron from about 50 to about 70 percent; and incidental impurities. The alloy is suitable for use in elevated temperature applications such as in valve seat inserts for combustion engines.

The steel pipe of the present invention is a low alloy high strength seamless steel pipe for oil country tubular goods including a composition containing, in terms of mass %, C: 0.23 to 0.27%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 0.5 to 1.0%, Nb: 0.02 to 0.05%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a value of a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve; of 1.02 or less and a yield strength of 655 MPa or more.

The steel pipe of the present invention is a low alloy high strength seamless steel pipe for oil country tubular goods including a composition containing, in terms of mass %, C: 0.23 to 0.27%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 0.5 to 1.0%, Nb: 0.02 to 0.05%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a value of a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve; of 1.02 or less and a yield strength of 655 MPa or more.

A low alloy high strength seamless steel pipe for oil country tubular goods is provided including a composition containing, in terms of mass %, C: 0.25 to 0.31%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, 0: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 1.1 to 1.6%, V: 0.01 to 0.06%, Nb: 0.005 to 0.015%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a ratio of the Ti content to the N content of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve of 1.02 or less and a yield strength of 861 MPa or more.

A low alloy high strength seamless steel pipe for oil country tubular goods is provided including a composition containing, in terms of mass %, C: 0.25 to 0.31%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, 0: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 1.1 to 1.6%, V: 0.01 to 0.06%, Nb: 0.005 to 0.015%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a ratio of the Ti content to the N content of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve of 1.02 or less and a yield strength of 861 MPa or more.

A low thermal expansion superalloy is composed of, in mass %, 0.1% or less of C, 0.1-1.0% of Si, 1.0% or less of Mn, 25-32% of Ni, more than 18% but less than 24% of Co, more than 0.25% but 1.0% or less of Al, 0.5-1.5% of Ti, more than 2.1% but less than 3.0% of Nb, 0.001-0.01% of B and 0.0005-0.01% of Mg, with the balance of Fe and unavoidable impurities, while satisfying Mg/S1, 52.91.235Ni+Co<55.8%, (Al+Ti+Nb) is 3.5-5.5%, and the F value is 8% or less. In the superalloy, a granular intermetallic compound containing Si, Nb, and Ni alone or in a total amount of 36 mass % or more is precipitated at a grain boundary of an austenite matrix, and an intermetallic compound including a larger concentration of Ni, Al, Ti, and Nb and having 50 nm or smaller of an average diameter is precipitated in the austenite matrix.

There is provided a steel material containing by wt %: 0.10 to 0.25% of carbon; 0.05 to 0.50% of silicon; 1.0 to 2.0% of manganese; 0.005 to 0.1% of aluminum; 0.010% or less of phosphorous; 0.0015% or less of sulfur; 30 to 70 ppm of nitrogen; 0.001 to 0.03% of titanium; 0.02 to 0.50% of copper; 0.05 to 0.50% of nickel; 0.0005 to 0.0040% of calcium; 0.001 to 0.03% of niobium; 0.001 to 0.03% of vanadium; one or two of 0.01 to 0.20% of chromium and 0.05 to 0.15% of molybdenum; and the balance being Fe and other unavoidable impurities, wherein a microstructure of the steel material contains at least 40 vol % of air-cooled bainite, and the balance being ferrite, and Nb(C,N) carbonitrides having a diameter of 5 to 30 nm are contained in the steel material in a content of 0.01 wt % or more.

The present disclosure relates to new nickel-iron-aluminum-chromium based alloys. Generally, the new alloys contain 20-40 at. % Ni, 15-40 at. % Fe, 5-20 at % Al, and 5-26 at. % Cr, the balance being optional incidental elements and unavoidable impurities. Generally, methods for producing the new alloys include one or more of heating a mixture above its liquidus temperature, then cooling the mixture below its solidus temperature, optionally hot and/or cold working the solid material into a final product form, then heating and quenching the solid material, and precipitation hardening the solid material.

A method and apparatus are present for manufacturing a part. The part is comprised of a metal alloy and is positioned to form a positioned part. An electromagnetic field is generated that heats the positioned part. A surface of the positioned part is exposed to an inert gas, while the electromagnetic field is generated to create an inverse thermal gradient between an exterior of the positioned part and an interior section of the positioned part to form a heat treated part.