A Sn-plated steel sheet according to the present invention includes a steel sheet, a Sn-plated layer that is provided on at least one surface of the steel sheet, and a film that is provided on a surface of the Sn-plated layer and includes zirconium oxide and tin oxide, in which an amount of the zirconium oxide in the film is 0.2 mg/m.sup.2 to 50 mg/m.sup.2 in terms of metal Zr amount, in a depth direction analysis by X-ray photoelectron spectroscopy, a depth position A at which an element concentration of Zr present as the zirconium oxide is maximum is positioned closer to a surface of the film than a depth position B at which an element concentration of Sn present as the tin oxide is maximum, and a distance between the depth position A and the depth position B in a depth direction is 0.5 nm or more.

A Sn-plated steel sheet according to the present invention includes a steel sheet, a Sn-plated layer that is provided on at least one surface of the steel sheet, and a film that is provided on a surface of the Sn-plated layer and includes zirconium oxide and tin oxide, in which an amount of the zirconium oxide in the film is 0.2 mg/m.sup.2 to 50 mg/m.sup.2 in terms of metal Zr amount, in a depth direction analysis by X-ray photoelectron spectroscopy, a depth position A at which an element concentration of Zr present as the zirconium oxide is maximum is positioned closer to a surface of the film than a depth position B at which an element concentration of Sn present as the tin oxide is maximum, and a distance between the depth position A and the depth position B in a depth direction is 0.5 nm or more.

The present disclosure provides a copper-phosphorus-tin brazing wire and a preparation method thereof, relates to the technical field of brazing materials. The copper-phosphorus-tin brazing wire is of a three-layer structure, the inner layer is Cu, the middle layer is Cu-14P alloy, and the outer layer is Sn, wherein the mass percentage of Sn is over 7%. The present disclosure solves the technical problems in the prior art that the copper-phosphorus-silver brazing filler metal is prone to produce defects such as pores and inclusions when brazing copper alloys, which leads to the decline of the mechanical properties of the joint, and simultaneously provides the preparation method of the copper-phosphorus-tin brazing wire, such that the technical problem that it is difficult to obtain copper-phosphorus-tin brazing wire with a wire diameter below 0.5 mm under the condition of high Sn content is solved.

A steel sheet for a drawn can has a predetermined chemical composition and has a ferrite single-phase structure with a crystal grain size number of 11.0 or more, the sheet thickness is 0.15 to 0.50 mm, in an L direction of the steel sheet after an ageing treatment at 100 C. for one hour, an yield strength YP is 220 to 290 MPa, a tensile strength TS is 330 to 390 MPa, a total elongation EL is 32% or more, an yield point elongation YP-EL is 0%, an average plastic strain ratio r.sub.m is more than 1.35, and an in-plane anisotropy r is 0.30 to +0.15.

A steel sheet for a drawn can has a predetermined chemical composition and has a ferrite single-phase structure with a crystal grain size number of 11.0 or more, the sheet thickness is 0.15 to 0.50 mm, in an L direction of the steel sheet after an ageing treatment at 100 C. for one hour, an yield strength YP is 220 to 290 MPa, a tensile strength TS is 330 to 390 MPa, a total elongation EL is 32% or more, an yield point elongation YP-EL is 0%, an average plastic strain ratio r.sub.m is more than 1.35, and an in-plane anisotropy r is 0.30 to +0.15.

The present invention concerns a copper strip for the making of electrical contacts, with a base material of copper or a copper alloy and a coating of tin, wherein the coating of tin has a proportion of insoluble, precipitation-forming elements of 0.003 to 1.0, preferably up to 0.5, preferably up to 0.05, particularly preferably up to 0.01 percent by weight. The invention further relates to a process for producing a copper strip for the manufacture of electrical contacts and a connector.

The present invention concerns a copper strip for the making of electrical contacts, with a base material of copper or a copper alloy and a coating of tin, wherein the coating of tin has a proportion of insoluble, precipitation-forming elements of 0.003 to 1.0, preferably up to 0.5, preferably up to 0.05, particularly preferably up to 0.01 percent by weight. The invention further relates to a process for producing a copper strip for the manufacture of electrical contacts and a connector.

A lead-free solder preform includes a core layer and adhesion layer coated over surfaces of the core layer, where the preform delivers the combined merits from constituent solder alloys of the core and adhesion layers to provide both high temperature performance and improved wetting in high-temperature solder applications such as die attach. The core layer may be formed of a Bi Alloy having a solidus temperature above 260 C., and the adhesion layer may be formed of Sn, a Sn alloy, a Bi alloy, In, or an In alloy having a solidus temperature below 245 C. The solder preform may be formed using techniques such as: (1) electroplating a core ribbon with an adhesion material, (2) cladding an adhesion material foil onto a core ribbon, and/or (3) dipping a core ribbon in a molten adhesion alloy bath to allow thin layers of adhesion material to adhere to a core ribbon.

The present invention belongs to the technical field of solder fluxes, and in particular relates to a water-soluble flux and a copper material pickling method. The water-soluble flux provided by the present invention includes an organic acid, an alcohol ether solvent, and deionized water. The organic acid is used as an active component of the present invention, and under the action of the alcohol ether solvent, oxides and impurities on the surface of a part to be welded can be sufficiently removed, and adhering residue of an acidic substance on the surface of the part to be welded can be reduced. In the process of tin plating of the part to be welded treated by the water-soluble flux provided by the present invention, the splash of tin liquid can be effectively inhibited, and the utilization rate of tin is improved.

A steel sheet for containers including a steel sheet, a Sn coated layer that is formed on at least one surface of the steel sheet, and a chemical treatment layer that is formed on the Sn coated layer. A variation amount in a yellowness index measured at one measurement point on the outermost surface of the chemical treatment layer is defined as YI, and represented by YI=YIYI.sub.0, wherein YI is the yellowness index measured after the steel sheet for containers is subjected to a retort treatment at a temperature of 130 C. for 5 hours, and YI.sub.0 is the yellowness index measured before the retort treatment. An average of absolute values of the YI obtained at a plurality of measurement points included in a unit area of the outermost surface is 5.0 or less.