Provided is a hot-stamped part including a base steel sheet, the base steel sheet including an amount of about 0.19 to about 0.25 wt % of carbon (C), an amount of about 0.1 to about 0.6 wt % of silicon (Si), an amount of about 0.8 to about 1.6 wt % of manganese (Mn), an amount of about 0.03 wt % or less of phosphorus (P), an amount of about 0.015 wt % or less of sulfur (S), an amount of about 0.1 to about 0.6 wt % of chromium (Cr), an amount of about 0.001 to about 0.005 wt % of boron (B), an amount of about 0.1 wt % or less of an additive, remaining iron (Fe), and other unavoidable impurities. In an indentation strain rate with respect to an indentation depth of about 200 nm to about 600 nm is observed in a nano indentation test, a number of indentation dynamic strain aging (DSA) is about 26 to about 40.

A method for producing a steel includes preparing a steel sheet having a chemical composition in % by mass of: C: 0.05 to 0.40%, Si: 0 to 2.0%, Mn: 1.0 to 3.0%, Al: 0.010 to 1.0%, P: more than 0% and 0.100% or less, S: more than 0% and 0.010% or less, N: more than 0% and 0.010% or less, B: 0.0005 to 0.010%, and iron; heating the steel sheet to Ac1 point (° C.) or higher and lower than Ac3 point (° C.)+10° C.; processing the steel sheet by applying a strain of 0.5% or more thereto at 675° C. or higher and lower than Ac3 point+10° C.; holding or gradually cooling the steel sheet at an average cooling rate of 0 to 15° C./sec for 1 second or more and 120 seconds or less; and cooling the steel sheet to Ms point (° C.)−50° C.

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.

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.

A surface-treated steel sheet of the present invention includes a base steel sheet and a Ni—Co—Fe alloy-plated layer on at least one surface of the base steel sheet, in which, in the alloy-plated layer, a Ni coating weight is 7.1 to 18.5 g/m.sup.2, a Co coating weight is 0.65 to 3.6 g/m.sup.2, and a total of the Ni coating weight and the Co coating weight is in a range of 9.0 to 20.0 g/m.sup.2. In a surface layer of the alloy-plated layer, a Co concentration is in a range of 20 to 60 atom %, and a Fe concentration is in a range of 5 to 30 atom %. In the alloy-plated layer, a region having a thickness of 2 μm or more, in which a total of a Ni concentration and the Co concentration is 10 atom % or more and the Fe concentration is 5 atom % or more, is present. The base steel sheet has a predetermined chemical composition, and a ferrite grain size number is 10 or more.

Disclosed is a 980 MPa grade cold-roll steel sheets with high hole expansion rate and higher percentage elongation, and manufacturing method thereof. The mass percents of chemical components in the steel sheet are: C: 0.08%-0.12%, Si: 0.1%-1.0%, Mn: 1.9%-2.6%, Al: 0.01%-0.05%, Cr: 0.1-0.55%, Mo: 0.1-0.5%, Ti: 0.01-0.1%, the rest being Fe and other inevitable impurities. The steel plate has a yield strength >600 MPa, a tensile strength >980 MPa, a percentage elongation >11%, a hole expansion rate ≥45%, and a tensile strength up to 980 MPa grade; the microscopic structure is ferrite plus bainite plus martensite, with the volume fraction content of ferrite >10%, the volume fraction content of bainite >30%, and the volume fraction content of martensite >15%; the microscopic structure further comprises nanoscale precipitates in uniform dispersion distribution, the average size of precipitates being less than 20 nm.

A metal mask material for OLED use reduced in amount warpage due to etching, a method for manufacturing the same, and a metal mask are provided. The metal mask material and metal mask of the present invention contain, by mass %, Ni: 35.0 to 37.0% and Co: 0.00 to 0.50%, have a balance of Fe and impurities, have thicknesses of 5.00 μm or more and 50.00 μm or less, and have amounts of warpage defined as maximum values in amounts of rise of four corners of a square shaped sample of the metal mask material of 100 mm sides when etching the sample from one surface until the thickness of the sample becomes ⅖ and placing the etched sample on a surface plate of 5.0 mm or less.

This disclosure provides a method of producing an alloy strip laminate including applying an external force directly to an alloy strip of a first laminate member having an adhesive layer and the alloy strip, to form a crack in the alloy strip and prepare a first laminate including the adhesive layer and the cracked alloy strip, applying an external force directly to an alloy strip of a second laminate member having an adhesive layer and the alloy strip, to form a crack in the alloy strip and prepare at least one second laminate including the adhesive layer and the cracked alloy strip, and laminating the at least one second laminate on the first laminate to prepare an alloy strip laminate in which the adhesive layer, and the alloy strip with the crack formed are alternately layered; and a production apparatus for an alloy strip laminate.

A method for producing a nanocrystalline alloy ribbon having a resin film, the method including a step of preparing an amorphous alloy ribbon capable of nanocrystallization, a step of performing a thermal treatment for nanocrystallization of the amorphous alloy ribbon with tension exerted on the amorphous alloy ribbon, to obtain a nanocrystalline alloy ribbon, and a step of causing the nanocrystalline alloy ribbon to be held on the resin film with an adhesive layer therebetween.

A high-strength steel sheet that has a predetermined component composition, that has a steel microstructure in which, in a thickness cross-section in a rolling direction, an area percentage of ferrite ranges from 5% to 30%, a total area percentage of tempered martensite and bainite ranges from 40% to 90%, pearlite constitutes 0% to 5%, a total area percentage of fresh martensite and retained γ ranges from 5% to 30%, a ratio of a total area percentage of the fresh martensite and the retained γ to a total area percentage of the tempered martensite, bainite, and pearlite is 0.5 or less, and a ratio of the fresh martensite and the retained γ adjacent to the ferrite with respect to the fresh martensite and the retained γ is 30% or more in total area percentage, and that has a yield strength of 550 MPa or more.