A method for the manufacture of a cold-rolled steel sheet of thickness e.sub.f between 0.5 mm and 3 mm is provided. At least two hot-rolled sheets of thickness e.sub.i are supplied and butt welded, so as to create a welded joint (S1) with a direction perpendicular to the direction of hot rolling. The at least two hot-rolled sheets are pickled by continuous passage through a bath, then the assembly is cold rolled, in a step (L1), to an intermediate thickness e.sub.int, the direction of cold rolling (DL.sub.1) coinciding with the direction of hot rolling. The cold rolling is carried out with a reduction ratio

[00001]${\mathrm{.Math.}}_1=\mathrm{Ln}\left(\frac{e_i}{e_{\mathrm{int}}}\right)$

such that:

[00002]$0.3.Math.5\frac{\mathrm{Ln}.Math..Math.\left(\frac{\mathrm{ei}}{e.Math..Math.\mathrm{int}}\right)}{\mathrm{Ln}.Math..Math.\left(\frac{e.Math.i}{e.Math.f}\right)}0.6.Math.5,$

then the welded joint (S1) is removed so as to obtain at least two intermediate cold-rolled sheets. Then the two intermediate cold-rolled sheets are butt welded, so as to create a welded joint (S2), the direction of which is perpendicular to the direction of hot rolling, then the assembly of the at least two intermediate cold-rolled and welded sheets is cold-rolled, in a step (L2), to the final thickness e.sub.f, the direction (DL.sub.2) of the cold rolling step (L2) coinciding with the direction of rolling (DL.sub.1).

A method for the manufacture of a cold-rolled steel sheet of thickness e.sub.f between 0.5 mm and 3 mm is provided. At least two hot-rolled sheets of thickness e.sub.i are supplied and butt welded, so as to create a welded joint (S1) with a direction perpendicular to the direction of hot rolling. The at least two hot-rolled sheets are pickled by continuous passage through a bath, then the assembly is cold rolled, in a step (L1), to an intermediate thickness e.sub.int, the direction of cold rolling (DL.sub.1) coinciding with the direction of hot rolling. The cold rolling is carried out with a reduction ratio

[00001]${\mathrm{.Math.}}_1=\mathrm{Ln}\left(\frac{e_i}{e_{\mathrm{int}}}\right)$

such that:

[00002]$0.3.Math.5\frac{\mathrm{Ln}.Math..Math.\left(\frac{\mathrm{ei}}{e.Math..Math.\mathrm{int}}\right)}{\mathrm{Ln}.Math..Math.\left(\frac{e.Math.i}{e.Math.f}\right)}0.6.Math.5,$

then the welded joint (S1) is removed so as to obtain at least two intermediate cold-rolled sheets. Then the two intermediate cold-rolled sheets are butt welded, so as to create a welded joint (S2), the direction of which is perpendicular to the direction of hot rolling, then the assembly of the at least two intermediate cold-rolled and welded sheets is cold-rolled, in a step (L2), to the final thickness e.sub.f, the direction (DL.sub.2) of the cold rolling step (L2) coinciding with the direction of rolling (DL.sub.1).

The invention relates to the use of a Q&P steel for production of a formed component (2) for high-wear applications, wherein the Q&P steel has a hardness of at least 230 HB, especially at least 300 HB, preferably at least 370 HB, and a bending angle of at least 60, especially at least 75, preferably at least 85, determined to VDA238-100, and/or a bending ratio of r/t<2.5, especially r/t<2.0, preferably r/t<1.5, where t corresponds to the material thickness of the steel and r to the (inner) bending radius of the steel.

The invention relates to the use of a Q&P steel for production of a formed component (2) for high-wear applications, wherein the Q&P steel has a hardness of at least 230 HB, especially at least 300 HB, preferably at least 370 HB, and a bending angle of at least 60, especially at least 75, preferably at least 85, determined to VDA238-100, and/or a bending ratio of r/t<2.5, especially r/t<2.0, preferably r/t<1.5, where t corresponds to the material thickness of the steel and r to the (inner) bending radius of the steel.

There is provided a high-strength galvanized steel sheet excellent in the external appearance of plating and the hydrogen brittleness resistance, and has a high yield ratio suitable for building materials and automotive collision-resistant parts, and a method for manufacturing the same.

Provided is a high-strength galvanized steel sheet including a specific component composition and a specific steel structure, the amount of diffusible hydrogen in the steel being 0.20 mass ppm or less; and a galvanizing layer provided on a surface of the steel sheet, having a content amount of Fe of 8 to 15% in mass %, and an attachment amount of plating per one surface of 20 to 120 g/m.sup.2, wherein the amount of Mn oxides contained in the galvanizing layer is 0.050 g/m.sup.2 or less, and a yield strength is 700 MPa or more and a yield strength ratio is 65% or more and less than 85%.

There is provided a high-strength galvanized steel sheet excellent in the external appearance of plating and the hydrogen brittleness resistance, and has a high yield ratio suitable for building materials and automotive collision-resistant parts, and a method for manufacturing the same.

Provided is a high-strength galvanized steel sheet including a specific component composition and a specific steel structure, the amount of diffusible hydrogen in the steel being 0.20 mass ppm or less; and a galvanizing layer provided on a surface of the steel sheet, having a content amount of Fe of 8 to 15% in mass %, and an attachment amount of plating per one surface of 20 to 120 g/m.sup.2, wherein the amount of Mn oxides contained in the galvanizing layer is 0.050 g/m.sup.2 or less, and a yield strength is 700 MPa or more and a yield strength ratio is 65% or more and less than 85%.

An etchant is described that includes an N-heterocyclic carbene and optionally an appropriate solvent. The etchant was effective at etching a metallic surface having, for example, a metal oxide and/or metal, in both solution phase and vapour-phase. The etchant has been shown to effectively etch oxidized copper and tungsten.

Disclosed is a method of fabricating an aluminum alloy member for bonding different materials. The method may include etching the aluminum alloy member with one or more etching solutions, and forming one or more undercuts on a surface of the aluminum alloy member.

Disclosed is a method of fabricating an aluminum alloy member for bonding different materials. The method may include etching the aluminum alloy member with one or more etching solutions, and forming one or more undercuts on a surface of the aluminum alloy member.

By first fluxing a steel long product with novel specific flux compositions, it is possible to continuously produce, more uniform, smoother and void-free galvanized coatings on such steel long products in a single hot dip galvanization step making use of zinc-aluminum alloys or zinc-aluminum-magnesium alloys with less than 95 wt. % zinc. This is achieved by providing specific amounts of lead chloride and tin chloride in a flux composition comprising (a) more than 40 and less than 70 weight % zinc chloride, (b) from 10 to 30 weight % ammonium chloride, (c) more than 6 and less than 30 weight % of a set of at least two alkali or alkaline earth metal chlorides.