A heat treated and cold rolled steel sheet having a composition including of the following elements 0.09%≤Carbon≤0.15%, 1.8%≤Manganese≤2.5%, 0.2%≤Silicon≤0.7%, 0.01%≤Aluminum≤0.1%, 0%≤Phosphorus≤0.09%, 0%≤Sulfur≤0.09%, 0%≤Nitrogen≤0.09%, 0%≤Niobium≤0.1%, 0%≤Titanium≤0.1%, 0%≤Chromium≤1%, 0%≤Molybdenum≤1%, 0%≤Vanadium≤0.1%, 0%≤Calcium≤0.005%, 0%≤Boron≤0.01%, 0%≤Cerium≤0.1%, 0%≤Magnesium≤0.05%, 0%≤Zirconium≤0.05% the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet comprising in area fraction, 65 to 85% Tempered Martensite, 0% to 5% Residual Austenite and a cumulative presence of Ferrite and Bainite between 15 and 35%.

A hot rolled and heat-treated steel sheet having a composition including, by weight percent C 0.12-0.25% Mn 3.0-8.0%, Si 0.70-1.50%, Al 0.3-1.2%, B 0.0002-0.004%, S≤0.010%, P≤0.020%, N≤0.008%, the remainder of the composition being iron and unavoidable impurities resulting from the smelting, and having a microstructure consisting of, in surface fraction: between 5% and 45% of ferrite, between 25% and 85% of partitioned martensite, the partitioned martensite having a carbides density less than 2×10.sup.6 /mm.sup.2, between 10% and 30% of retained austenite, less than 8% of fresh martensite, a part of the fresh martensite being combined with retained austenite in the shape of martensite-austenite islands in total surface fraction less than 10%, and a pancaking index lower than 5.

The present disclosure relates to a zinc-based coated steel material having excellent corrosion resistance and spot weldability and, more particularly, to a zinc-based coated steel material plated with a multilayer zinc alloy, which has two or more layers, and having excellent corrosion resistance and spot weldability. A zinc-based coated steel material according to an aspect of the present disclosure includes: a base steel; and a multilayer zinc-based plating layer composed of two or more discriminated plating layers, in which the multilayer zinc-based plating layer may include Mg of 0.12˜0.64 percent by weight.

Provided is a steel sheet and a method for manufacturing the same, the steel sheet, which can be used for automobile parts and the like, having superb bendability, and excellent balance of strength and ductility and of strength and hole expansion ratio.

Provided is a steel sheet which can be used for automobile parts and the like, and relates to a steel sheet having an excellent balance of strength and ductility, an excellent balance of strength and hole expansibility and excellent bending workability, and a method for manufacturing same.

To provide a high-strength seamless stainless steel pipe for oil well that has high strength, is excellent in hot workability, has excellent carbon dioxide gas corrosion resistance, and is excellent in SSC resistance under a low temperature environment. A high-strength seamless stainless steel pipe for oil well having a composition containing the particular components, the balance being Fe and unavoidable impurities, and satisfying certain expressions, having a number density of an inclusion having a major axis of 5 μm or more and 0.5<Ti/(Ti+Al+Mg+Ca)<1.0 of 0.5 per mm.sup.2 or more and 3 per mm.sup.2 or less, and having a yield strength of 655 MPa or more, wherein in 0.5<Ti/(Ti+Al+Mg+Ca)<1.0, Ti, Al, Mg, and Ca represent the contents (% by mass) of the elements in the inclusion, and an element that is not contained is designated as 0.

A hot-rolled steel sheet has a predetermined chemical composition in which a microstructure includes 99% or more of martensite by volume fraction and a remainder in microstructure including residual austenite and ferrite, in a cross section parallel to a rolling direction, an average aspect ratio of prior austenite grains is less than 3.0, a proportion of sulfides having an aspect ratio of more than 3.0 among sulfides having an area of 1.0 μm.sup.2 or more is 1.0% or, less, in a thickness middle portion, and a pole density of {211} <011> orientation is 3.0 or less, and a tensile strength TS is 980 MPa or higher.

The present invention relates to a method for producing an article out of a maraging steel, wherein the article is successively subjected to a solution annealing and heat treatment, wherein the steel has the following composition in weight percent: C=0.01-0.05 Si=0.4-0.8 Mn=0.1-0.5 Cr=12.0-13.0 Ni=9.5-10.5 Mo=0.5-1.5 Ti=0.5-1.5 Al=0.5-1.5 Cu=0.0-0.05 Residual iron and smelting-induced impurities.

Systems and methods disclosed herein relate to the manufacture of metallic material with a thermal expansion coefficient in a predetermined range, comprising: deforming, a metallic material comprising a first phase and a first thermal expansion coefficient. In response to the deformation, at least some of the first phase is transformed into a second phase, wherein the second phase comprises martensite, and orienting the metallic material in at least one predetermined orientation, wherein the metallic material, subsequent to deformation, comprises a second thermal expansion coefficient, wherein the second thermal expansion coefficient is within a predetermined range, and wherein the thermal expansion is in at least one predetermined direction. In some embodiments, the metallic material comprises the second phase and is thermo-mechanically deformed to orient the grains in at least one direction.

A cemented carbide comprising 55-90 parts by mass of WC particles and 10-45 parts by mass of a Fe-based binder phase; the binder phase having a composition comprising 0.5-10% by mass of Ni, 0.2-2% by mass of C, 0.5-5% by mass of Cr, 0.2-2.0% by mass of Si, and 0.1-5% by mass of W, the balance being Fe and inevitable impurities, and containing 0.05-2.0% by area of Fe—Si—O-based particles.