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.

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 high-strength steel member having a predetermined chemical composition, having a tensile strength of 1,000 MPa or higher, containing 0.10% or more of, in terms of percent (%) by area, at least one Ti precipitate that has an average size of from 30 to 200 nm in terms of an average equivalent circle diameter and is selected from the group consisting of a Ti carbide, a Ti nitride, and a composite compound thereof, at a location of 1 mm in depth from a surface of the steel member, and containing 0.5 ppm by mass or more of non-diffusible hydrogen that is released in a temperature range of from 400 to 800 C. in a thermal desorption hydrogen analysis.

Steel for a crankshaft includes 0.37 to 0.42 wt % of carbon (C), 0.55 to 0.70 wt % of silicon (Si), 1.45 to 1.65 wt % of manganese (Mn), 0.025 wt % or less (excluding 0 wt %) of phosphorus (P), 0.020 to 0.035 wt % of sulfur (S), 0.15 to 0.30 wt % of chromium (Cr), 0.035 to 0.055% of vanadium (V), and the remainder of Fe and other inevitable impurities. The steel for a crankshaft has strength that is maintained high even when reducing the amount of vanadium.

A rolled wire rod for spring steel contains, as a chemical composition, by mass %: C: 0.42% to 0.60%; Si: 0.90% to 3.00%; Mn: 0.10% to 1.50%; Cr: 0.10% to 1.50%; B: 0.0010% to 0.0060%; N: 0.0010% to 0.0070%; Mo: 0% to 1.00%; V: 0% to 1.00%; Ni: 0% to 1.00%; Cu: 0% to 0.50%; Al: 0% to 0.100%; Ti: 0% to 0.100%; Nb: 0% to 0.100%; P: limited to less than 0.020%; S: limited to less than 0.020%; and a remainder including Fe and impurities, the carbon equivalent (Ceq) is 0.75% to 1.00%, the area fraction of tempered martensite and bainite included in a microstructure is 90% or greater, the tensile strength is 1,350 MPa or less, and the reduction of area is 40% or greater.

Provided is a steel wire rod for wire drawing containing, in terms of % by mass, C: from 0.90 to 1.20%, Si: from 0.10 to 1.30%, Mn: from 0.20 to 1.00%, Cr: from 0.20 to 1.30%, Al: from 0.005 to 0.050%, and the balance being composed of Fe and impurities, wherein a content of each N, P, and S, which are contained as the impurities, is N: from 0.0070% or less, P: from 0.030% or less, S: from 0.010% or less, and the steel wire rod having a metallographic structure of which 95% or more by volume ratio is a lamellar pearlite structure, wherein the lamellar pearlite structure has an average lamellar spacing of from 50 to 75 nm, an average length of cementites in the lamellar pearlite structure is 1.0 to 4.0 m, and a percentage of a number of cementites having a length of 0.5 m or less among the cementites in the lamellar pearlite structure is 20% or less.

Along with higher performance of products, materials are also required to achieve both a high strength and favorable magnetic properties according to applications of products. Therefore, the present invention provides an FeCo-based alloy bar which enables both a high strength and favorable magnetic properties to be achieved.

An FeCo-based alloy bar contains 30% to 80% of crystal grains having a grain orientation spread (GOS) value of 0.5 or more in terms of an area ratio, and having an average crystal grain size number of more than 8.5 and 12.0 or less. The FeCo-based alloy bar of the present invention has a high 0.2% yield strength after magnetic annealing so that it can support various high-strength applications.

The present invention relates to a high-strength wire rod superior in impact toughness and a manufacturing method therefor and, more particularly, to a high-strength wire rod having superior impact toughness, which can be preferably used as a material for industrial machines or automobiles exposed to various external load environments, and a manufacturing method therefor.

A wire rod according to an aspect of the present invention includes a chemical composition within a predetermined range; in which an average value of % Mn+2 x % Cr over an entirety of the wire rod is 0.50% to 1.00%; 90% or more of a metallographic structure is pearlite by area fraction, and the area fraction of the cementite is less than 3%; a maximum grain size of TiN is less than 15 m; a maximum value of % Mn+2 x % Cr in a region where both a S content and an 0 content are less than 1% in a central portion is 2.0 times or less than the average value of % Mn+2x % Cr over the entirety of the wire rod, and a ratio of the maximum value to a minimum value of % Mn+2x % Cr in a region where both a S content and an 0 content are less than 1% in an outer circumferential portion is 2.0 or less.

An aspect of the present invention relates to a wire rod for springs with high strength and excellent corrosion fatigue resistance, in which a combination of Cr, Cu, and Ni content is controlled to an appropriate level, the maximum depth of corrosion pits is set to be below a certain level, and fine carbides containing Mo are set to be at a certain level or greater.