An aluminium alloy foil with a thickness of maximum 12 μm, maximum 9 μm or less than 8 μm. The aluminium alloy foil is an AA1xxx or A8xxx aluminium alloy in the annealed state. In addition, a method for manufacturing an aluminium alloy foil and its use. The object of proposing an aluminium alloy foil with improved barrier properties, a method for its manufacture and a use of the aluminium alloy foil is achieved in that the aluminium alloy foil has a maximum number of pores with a pore size of 1 μm to 200 μm of maximum 12 per dm.sup.2, maximum 8 per dm.sup.2 or maximum 6 per dm.sup.2. In addition, a method is specified for how this aluminium alloy foil can be manufactured.

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.

A heat treated cold rolled steel sheet with the following elements, 0.1%≤C≤0.2%; 1.2%≤Mn≤2.2%; 0.05%≤Si≤0.6%; 0.001%≤Al≤0.1%; 0.01%≤Cr≤0.5 %; 0%≤S≤0.09%; 0%≤P≤0.09%; 0%≤N≤0.09%; 0%≤Mo≤0.5%; 0%≤Ti≤0.1%; 0%≤Nb≤0.1%; 0%≤V≤0.1%; 0%≤Ni≤1%; 0%≤Cu≤1%; 0%≤Ca≤0.005%; 0%≤B≤0.05%; the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel having, by area percentage, 60% to 85% of tempered martensite, a cumulated amount of ferrite and bainite of 15% to 38%, an optional amount of residual austenite of 0% to 5% and an optional amount of fresh martensite of 0 to 5%.

A steel sheet for crown cap having excellent formability from which a crown cap having an excellent pressure resistance can be produced without an expensive soft liner even if the steel sheet is subjected to sheet metal thinning, the steel sheet having: a chemical composition containing, in mass %, C: more than 0.006% and 0.012% or less, Si: 0.02% or less, Mn: 0.10% or more and 0.60% or less, P: 0.020% or less, S: 0.020% or less, Al: 0.01% or more and 0.07% or less, and N: 0.0080% or more and 0.0200% or less, with the balance being Fe and inevitable impurities; and a percentage of a region of more than 0% and less than 20% at a position of ½ of a sheet thickness, the region having a dislocation density of 1×10.sup.14 m.sup.−2 or less.

The high-strength thin steel sheet has a chemical composition containing C, Si, Mn, P, S, Al, and N, with the balance being Fe and inevitable impurities, and a complex structure containing ferrite, tempered martensite, and bainite, where a volume fraction of a total of tempered martensite and bainite containing five or more carbides with a particle size of 0.1 μm or more and 1.0 μm or less in a grain with respect to a total of the tempered martensite and the bainite is 85% or more, and C mass % and Mn mass % in a region of 20 μm or less in a thickness direction from a surface of the steel sheet are each 20% or less with respect to C mass % and Mn mass % in a region of 100 μm or more and 200 μm or less from the surface of the steel sheet.

A steel sheet for hot press comprises: a predetermined chemical composition; and a steel microstructure that includes ferrite and cementite and in which Mnθ/Mnα is 1.4 or more, where Mnα is a Mn concentration of the ferrite and Mnθ is a Mn concentration of the cementite.

A method for producing a hot-rolled steel sheet, a method for producing a cold-rolled full-hard steel sheet, and a method for producing a heat-treated sheet are provided herein. The methods comprising hot rolling a steel material of a composition comprising, in mass %, C: 0.05 to 0.12%, Si: 0.80% or less, Mn: 1.30 to 2.10%, P: 0.001 to 0.050%, S: 0.005% or less, Al: 0.01 to 0.10%, N: 0.010% or less, one or more selected from Cr in an amount of 0.05 to 0.50%, and Mo in an amount of 0.05 to 0.50%, one or more selected from Ti in an amount of 0.01 to 0.10%, Nb in an amount of 0.01 to 0.10%, and V in an amount of 0.01 to 0.10%, and the balance Fe and unavoidable impurities.

A martensitic stainless steel sheet has a composition containing, (mass %), from 0.10 to 0.15% of C, from 0.05 to 0.80% of Si, from 0.05 to 2.00% of Mn, 0.040% or less of P, 0.003% or less of S, from 0.05 to 0.50% of Ni, from 11.0 to 15.0% of Cr, from 0.02 to 0.50% of Cu, from 0.005 to 0.06% of N, from 0.001 to 0.20% of Al, from 0 to 1.00% of Mo, from 0 to 0.50% of V, from 0 to 0.01% of B, balance Fe and unavoidable impurities. An M value=420C−11.5Si+7Mn+23Ni−11.5Cr−12Mo−10V+9Cu−52Al+470N+189 is 100 or more. A carbonitride number density having a circle equivalent diameter of 1.0 μm or more is 15.0 or less per 0.01 mm.sup.2. 0.2% yield strength is 1,100 N/mm.sup.2 or more.

A ferritic stainless steel sheet and a steel pipe as a material suitable for a heat-resistant component that is required to have especially excellent formability are provided. The ferritic stainless steel sheet contains 10 to 20 mass % of Cr and a predetermined amount of C, Si, Mn, P, S, Al and one or both of Ti and Nb, a {111}-orientation intensity being 5 or more and {411}-orientation intensity being less than 3 at a portion in the vicinity of a sheet-thickness central portion of the ferritic stainless steel sheet. Further, with similar composition and by setting {111}<110>-orientation intensity at 4.0 or more and {311}<136>-orientation intensity at less than 3.0, a relationship r.sub.m≥−1.0t+3.0 (t(mm): sheet thickness, r.sub.m: average r-value) is satisfied, thereby providing a ferritic stainless steel sheet and a steel pipe with excellent formability.

In a method for producing a flat steel product made of high-strength manganese steel, a hot or cold strip is provided with an alloy composition containing (in wt %): C: 0.0005 to 0.9; Mn: 4 to 12; Al: up to 10; P: <0.1; S: <0.1; N: <0.1; the remainder being iron, including unavoidable steel-alloying elements, with optional addition of one or more of the following elements (in wt %): Si: up to 6; Cr: up to 6; Nb: up to 1; V: up to 1.5; Ti: up to 1.5; Mo: up to 3; Sn: up to 0.5; Cu: up to 3; W: up to 5; Co: up to 8; Zr: up to 0.5; Ta: up to 0.5; Te: up to 0.5, B: up to 0.15. The hot or cold strip is flexibly rolled to a final thickness at a temperature of 60° C. to below Ac3 prior to a first rolling step.