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.

[00001]$0.005\le \left(\left[\text{P}\right]+\left[\text{As}\right]\right)\le 0.015$

(In Formula 1, [P] and [As] represent a content (wt%) of P and As, respectively.)

[00002]$\left[\text{STD}\right]\le 0.7\times \left[\text{GS}\right]$

([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.)

The present disclosure provides a hot-press formed part comprising a plated steel sheet and an aluminum alloy plated layer formed on the plated steel sheet, wherein the aluminum alloy plated layer comprises: an alloying layer (I) formed on the plated steel sheet and containing, by weight %, 5-30% of Al; an alloying layer (II) formed on the alloying layer (I) and containing, by weight %, 30 to 60% of Al; an alloying layer (III) formed on the alloying layer (II) and containing, by weight %, 20-50% of Al and 5-20% of Si; and an alloying layer (IV) formed continuously or discontinuously on at least a part of the surface of the alloying layer (III), and containing 30-60% of Al, wherein the rate of the alloying layer (III) exposed on the outermost surface of the aluminum alloy plated layer is 10% or more.

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.

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.

An method of manufacturing a hot press-formed member comprises heating a blank of an aluminum-based plated steel sheet in a heating furnace, removing the heated blank from the heating furnace and conveying the removed blank between an upper mold portion and a lower mold portion of a mold, mounted on a press, to be seated; and performing a forming process after the upper mold portion of the mold is in contact with the seated blank.

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.

The present invention relates to a formed product used in vehicle components and the like, and to a method for manufacturing the same. The present invention provides heat treatable steel, a formed product using the same having ultra-high strength and excellent durability, and a method for manufacturing the same, wherein the heat treatable steel contains, in wt %, C (0.22-0.42%), Si (0.05-0.3%), Mn (1.0-1.5%), Al (0.01-0.1%), P (0.01% or less (including 0), S (0.005% or less), Mo (0.05-0.3%), Ti (0.01-0.1%), Cr (0.05-0.5%), B (0.0005-0.005%), N (0.01% or less), the balance Fe, and other inevitable impurities, Mn and Si satisfying Relationship formula (1), below, Mo/p satisfying Relationship formula (2), below: [Relationship formula 1] Mn/Si≧5 [Relationship formula 2] Mo/P≧15.

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.

Method of hot press forming an article from zinc or zinc alloy coated steel, wherein the steel is a product obtained by: casting the molten steel into slabs; reheating the slabs; hot rolling the steel into a strip, preferably with an FRT above Ar3; coiling the hot rolled steel strip; pickling the hot rolled steel strip; continuous annealing the strip; hot dip coating the steel strip with the zinc or zinc alloy whilst: using a dipping time of 3 seconds or more; maintaining in the hot dip bath a bath temperature of 420° C. to 500° C.; wherein the zinc bath contains essentially zinc, at least 0.1% Al, and optionally up to 5% Al and optionally up to 4% Mg, the rest of the bath including further elements all individually less than 0.3%, and unavoidable impurities; hot press forming the article.

An embodiment of the present invention provides steel for hot forming, a hot-formed member, and methods for manufacturing same, the steel comprising, by wt %, 0.06-0.1% of C, 0.05-0.6% of Si, 0.6-2% of Mn, 0.05% or less of P, 0.02% or less of S, 0.01-0.1% of Al, 0.01-0.8% of Cr, 0.01-0.5% of Mo, 0.02% or less of N, and the remainder of Fe and inevitable impurities, wherein an alloy factor represented by relational expression 1 below is 7 or more, and the number of carbides having a circular equivalent diameter of 0.5 μm or greater is 10.sup.5/mm.sup.2 or less.

Alloy factor=I(Mn)×I(Si)×I(Cr)×I(Mo)  [Relational expression 1] where the I values for the components are I(Mn)=3.34×Mn+1, I(Si)=0.7×Si+1, I(Cr)=2.16×Cr+1, and I(Mo)=3×Mo+1, respectively, and the content of each component is expressed as wt %.