Patent classifications
C21D8/00
NON-ORIENTED ELECTRICAL STEEL SHEET AND METHOD FOR MANUFACTURING SAME
An embodiment of the present invention provides a non-oriented electrical steel sheet including. in wt%: Si: 2.5 to 4.0 %, Mn: 0.1 to 1.0 %, Al: 0.5 to 1.5 %, P: 0.002 to 0.015 %, and As: 0.002 to 0.01 %, and the balance of Fe and inevitable impurities, and satisfying Formula 1 and Formula 2.
(In Formula 1, [P] and [As] represent a content (wt%) of P and As, respectively.)
([GS] is an average grain size (.Math.m) measured when 10,000 or more grains having a grain size of 5 to 500 .Math.m are observed on a surface of the steel sheet, and STD is a standard deviation (.Math.m) at that time.)
Hot-rolled steel sheet for electrical steel sheet production and method of producing same
With a hot-rolled steel sheet for electrical steel sheet production having a scale layer on the surface, where the surface of the steel sheet has a lightness L* as defined in JIS Z 8781-4: 2013 satisfying 30≤L*≤50, and chromaticities a* and b* as defined in JIS Z 8781-4: 2013 satisfying −1≤a*≤2 and −5≤b*≤3 respectively, and with one end portion in the longitudinal direction of a coil as a reference, a color difference ΔE.sub.ab* as defined in JIS Z 8781-4: 2013 at the central portion and at the opposite end portion satisfies ΔE.sub.ab*≤8, it is possible to obtain a grain-oriented electrical steel sheet where the variation of properties in a product coil is small.
High-strength structural steel material having excellent fatigue crack propagation inhibitory characteristics and manufacturing method therefor
A high-strength structural steel material having excellent fatigue crack propagation inhibitory characteristics according to an aspect of the present invention contains, by weight, 0.02-0.12% of C, 1.7-2.5% of Mn, 0.01-0.8% of Si, 0.005-0.5% of Al, and the balance Fe and unavoidable impurities, wherein a microstructure of the structural steel sheet material is divided into a surface layer portion outside and a central portion inside along a thickness direction; the surface layer portion comprises tempered bainite as a matrix structure, fresh martensite as a second structure, and austenite as a residual structure; and the central portion comprises lath bainite.
Paramagnetic hard stainless steel and manufacturing process thereof
A paramagnetic stainless steel with a chemical composition including by weight: 26≤Cr≤40%, 5≤Ni≤20%, 0≤Mn≤5%, 0≤Al≤5%, 0≤Mo≤3%, 0≤Cu≤2%, 0≤Si≤5%, 0≤Ti≤1%, 0≤Nb≤1%, 0≤C≤0.1%, 0≤N≤0.1%, 0≤S≤0.5%, 0≤P≤0.1%, the remainder consisting of iron and any impurities each having a content less than or equal to 0.5%, the steel having a hardness HV10 between 500 and 900. It also relates to a part particularly a horological component made of this steel and to the process for manufacturing the part.
Martensitic Stainless Steel with High Strength, High Toughness and High Corrosion Resistance
A method of producing a high performance stainless steel exhibiting corrosion resistance even under a very severe corrosion environment at temperatures of equal to or higher than 180° C., for example, 220° C., while maintaining strength and toughness by improving the corrosion resistance of a conventional martensitic stainless steel with high strength. The martensitic stainless steel includes, in mass %, C: 0.005% to 0.05%, Si: equal to or less than 1.0%, Mn: equal to or less than 2.0%, Cr: 16 to 18%, Ni: 2.5 to 6.5%, Mo: 1.5 to 3.5%, W: equal to or less than 3.5%, Cu: equal to or less than 3.5%, V: 0.01 to 0.08%, Sol.Al: 0.005 to 0.10%, N: equal to or less than 0.05%, and Ta: 0.01 to 0.06%, and the balance Fe with inevitable impurities.
METAL PLATE
The object of the present invention is to provide a metal plate capable of manufacturing a deposition mask in which dispersion of positions of through-holes is restrained. A thermal recovery rate is defined as parts per million of a difference a distance between to measurement points on a sample before a heat treatment and a distance therebetween after the heat treatment, relative to the distance therebetween before the heat treatment. In this case, an average value of the thermal recovery rates of the respective samples is not less than −10 ppm and not more than +10 ppm, and (2) a dispersion of the thermal recovery rates of the respective samples is not more than 20 ppm.
Bolt and fastened structure
A bolt of the present invention has a composition comprising: 0.50 mass % or greater and 0.65 mass % or less of carbon (C), 1.5 mass % or greater and 2.5 mass % or less of silicon (Si), 1.0 mass % or greater and 2.0 mass % or less of chromium (Cr), 0.2 mass % or greater and 1.0 mass % or less of manganese (Mn), 1.5 mass % or greater and 5.0 mass % or less of molybdenum (Mo), wherein a total amount of phosphorous (P) and sulfur (S) as impurities is 0.03 mass % or less, the remaining is iron (Fe), and the bolt comprises an iron based oxide film with a film thickness of 3 μm or greater and 20 μm or less on the surface thereof. The bolt has excellent delayed fracture resistance and reliably provides a fastening axial force.
HIGH-PERFORMANCE THERMOFORMED COMPONENT PROVIDED WITH COATING, AND MANUFACTURING METHOD THEREFOR
A high-performance thermoformed component provided with a coating, and a manufacturing method therefor. The thermoformed component comprises a substrate and a coating thereon. The substrate comprises the following ingredients in percentage by weight: 0.01-0.8% of C, 0.05-1.0% of Si, 0.1-5% of Mn, 0.001-0.3% of P, 0.001-0.1% of S, 0.001-0.3% of Al, 0.001-0.5% of Ti, 0.0005-0.1% of B, 0.001-0.5% of Nb, 0.001-0.5% of V, and the remainder being Fe and other unavoidable impurities. The appearance of the thermoformed component has no color difference and no mottling. The surface oxygen content of the thermoformed component is 0.1-20 wt. %, and the ratio of the standard deviation to the average value of the surface oxygen content satisfies: 0<standard deviation of oxygen content/average value of oxygen content ≤0.3. In the manufacturing method, a coated steel plate that has undergone heat treatment, transfer processing, and hot stamping is not treated with oil.
Grain-oriented electrical steel sheet and method for manufacturing same
Provided is a grain-oriented electrical steel sheet having better transformer iron loss property than conventional grain-oriented electrical steel sheets. A grain-oriented electrical steel sheet comprises: a steel substrate; a forsterite film on a surface of the steel substrate; and a Cr-depleted layer at a boundary between the steel substrate and the forsterite film, the Cr-depleted layer having a Cr concentration that is 0.70 times to 0.90 times a Cr concentration of the steel substrate.
Grain-oriented electrical steel sheet and method for manufacturing same
Provided is a grain-oriented electrical steel sheet that has excellent magnetic properties and can be manufactured by secondary recrystallization orientation control using coil annealing with high productivity. A grain-oriented electrical steel sheet comprises a specific chemical composition, wherein an average value of a deviation angle (α.sup.2+β.sup.2).sup.1/2 calculated from a deviation angle α from ideal Goss orientation around an ND rotation axis and a deviation angle β from ideal Goss orientation around a TD rotation axis is 5.0° or less, and an area ratio R.sub.β of crystal grains with β≤0.50° is 20% or less.