Disclosed herein is an electroslag welding wire containing, by mass % based on total mass of the wire: C: more than 0% and 0.07% or less; Si: more than 0% and 0.50% or less; Mn: more than 0% and 1.0% or less; Ni: 6.0 to 15.0%; and Fe: 79% or more. The electroslag welding wire satisfies the following relationship (1): 0.150≤C+Si/30+Mn/20+Ni/60≤0.300 (1).

A nickel-containing steel for low temperature according to an aspect of the present invention has a chemical composition within a predetermined range, in which a metallographic structure of a thickness middle portion contains 2.0 vol % to 20.0 vol % of an austenite phase, an average grain size of prior austenite grains is 3.0 μm to 15.0 μm, an average aspect ratio of the prior austenite grains is 1.0 to 2.4, a plate thickness is 4.5 mm to 30 mm, the chemical composition and the average grain size of the prior austenite grains are further limited depending on the plate thickness, a yield stress at room temperature is 460 MPa to 710 MPa, and a tensile strength at the room temperature is 560 MPa to 810 MPa.

A Ni steel has a chemical composition within a predetermined range, in which a metallographic structure of a thickness middle portion contains 2.0 vol % to 20.0 vol % of an austenite phase, an average grain size of prior austenite grains is 3.0 μm to 12.0 μm, an average aspect ratio of the prior austenite grains is 2.6 to 10.0, a plate thickness is 4.5 mm to 20 mm, a yield stress at room temperature is 590 MPa to 710 MPa, and a tensile strength at the room temperature is 690 MPa to 810 MPa, when the plate thickness is more than 16 mm, the Ni steel contains Ni: 11.5% or more, and when the plate thickness is 16 mm or less and the Ni steel contains Ni: less than 11.5%, the average grain size of the prior austenite grains is 6.0 μm or less.

A high-strength hot-rolled steel sheet that has excellent punching workability and hole expandability, and a method for manufacturing the same. The hot-rolled steel sheet has a tensile strength of 980 MPa or more. The hot-rolled steel sheet has a chemical composition containing C, Si, Mn, P, S, Al, N, Ti, Cr, and B, and has a microstructure including a bainite phase having an area ratio of 85% or more as a main phase, and a martensite phase or martensite-austenite constituent having an area ratio of 15% or less as a second phase, the balance being a ferrite phase. The second phase has an average grain diameter of 3.0 μm or less, prior-austenite grains have an average aspect ratio of 1.3 or more and 5.0 or less, and recrystallized prior-austenite grains have an area ratio of 15% or less relative to non-recrystallized prior-austenite grains.

A high-strength hot-rolled steel sheet that has excellent punching workability and hole expandability, and a method for manufacturing the same. The hot-rolled steel sheet has a tensile strength of 980 MPa or more. The hot-rolled steel sheet has a chemical composition containing C, Si, Mn, P, S, Al, N, Ti, Cr, and B, and has a microstructure including a bainite phase having an area ratio of 85% or more as a main phase, and a martensite phase or martensite-austenite constituent having an area ratio of 15% or less as a second phase, the balance being a ferrite phase. The second phase has an average grain diameter of 3.0 μm or less, prior-austenite grains have an average aspect ratio of 1.3 or more and 5.0 or less, and recrystallized prior-austenite grains have an area ratio of 15% or less relative to non-recrystallized prior-austenite grains.

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 permanent magnet may include a Fe.sub.16N.sub.2 phase in a strained state. In some examples, strain may be preserved within the permanent magnet by a technique that includes etching an iron nitride-containing workpiece including Fe.sub.16N.sub.2 to introduce texture, straining the workpiece, and annealing the workpiece. In some examples, strain may be preserved within the permanent magnet by a technique that includes applying at a first temperature a layer of material to an iron nitride-containing workpiece including Fe.sub.16N.sub.2, and bringing the layer of material and the iron nitride-containing workpiece to a second temperature, where the material has a different coefficient of thermal expansion than the iron nitride-containing workpiece. A permanent magnet including an Fe.sub.16N.sub.2 phase with preserved strain also is disclosed.

A method of manufacturing a cutting member include cutting a first metal material to form a first portion of the cutting member; cutting second metal material to form a second portion of the cutting member, wherein a first edge of the second portion has at least two line segments, a curve formed by the at least two line segments being mathematically continuously differentiable; welding the first portion and the second portion together; raising the cutting member blank to a first temperature at a first rate and holding raising the cutting member blank from the first temperature to a second temperature at a second rate lower than the first rate and holding, and raising the cutting member blank from the second temperature to a third temperature at a third rate not higher than the second rate and holding.

A method of manufacturing a cutting member include cutting a first metal material to form a first portion of the cutting member; cutting second metal material to form a second portion of the cutting member, wherein a first edge of the second portion has at least two line segments, a curve formed by the at least two line segments being mathematically continuously differentiable; welding the first portion and the second portion together; raising the cutting member blank to a first temperature at a first rate and holding raising the cutting member blank from the first temperature to a second temperature at a second rate lower than the first rate and holding, and raising the cutting member blank from the second temperature to a third temperature at a third rate not higher than the second rate and holding.

The present disclosure relates to a steel for pressure vessels used in a hydrogen sulfide atmosphere, and relates to a steel material for pressure vessels having excellent resistance to hydrogen induced cracking (HIC) and a manufacturing method thereof.