A Sn-plated steel sheet including a base plated steel sheet having a steel sheet, a Sn-plated layer on at least one surface of the steel sheet, and a film layer containing a zirconium oxide and a tin oxide. An adhesion amount of Sn per surface of the Sn-plated steel sheet is 0.1 g/m.sup.2 or more and 15 g/m.sup.2 or less, an amount of the zirconium oxide in the film layer is in a range of 1 mg/m.sup.2 or more and 30 mg/m.sup.2 or less in terms of an amount of metal Zr, a peak position of a binding energy of Sn3d.sub.5/2 of the tin oxide is 1.4 eV or more and less than 1.6 eV from a peak position of a binding energy of metal Sn, and a quantity of electricity required for reduction of the tin oxide is more than 5.0 mC/cm.sup.2 and 20 mC/cm.sup.2 or less.

An antimicrobial air treatment device and a method of its construction. The antimicrobial air treatment device comprises an antimicrobial metal nanoparticle mesh comprising a steel support mesh and a layer of copper nanoparticles disposed on the steel support mesh. The antimicrobial air treatment device may be in the form of a facemask or a component of a moving air filtration system such as an HVAC system, an automobile cabin air filtration system, and an air purifier. The antimicrobial air treatment device may contain one or more filtration layers of filtration medium. The method of constructing the antimicrobial air treatment device involves the preparation of the antimicrobial metal nanoparticle mesh by an electrodeposition technique.

In certain aspects, a coated steel substrate comprises a single or multiple-layer electroplated aluminum coating over a steel substrate. The multiple-layer electroplated aluminum coating comprises one or more porous layers and one or more compact layers. The one or more porous layers comprise a material selected from a group consisting of aluminum and aluminum alloys. The one or more compact layers comprise a material selected from a group consisting of aluminum and aluminum alloys. In certain aspects, a method of depositing a multiple-layer aluminum coating over a steel substrate includes electroplating one or more porous aluminum layers over the steel substrate. The one or more porous aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys. One or more compact aluminum layers are electroplated over the steel substrate. The one or more compact aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys.

A method of manufacturing blind rivets is revealed. First cutting a steel wire rod to get a rod with required length and forming a head portion at one end of the rod. Then performing threading on an outer surface of the rod to form outer threads and carrying out heat treatment including quenching and tempering at 380° C.±50° C. to get a threaded rod. Next cutting a steel wire rod according to a length required to get a tube and forming a through hole axially penetrating the tube and corresponding to the threaded rod. Then forming a mounting portion at an outer edge of one end of the tube, carrying out optical heat treatment at 1100° C.±100° C., and performing electroplating to get an outer tube. Lastly the threaded rod is inserted into the through hole of the outer tube and the assembly is completed.

A method of manufacturing blind rivets is revealed. First cutting a steel wire rod to get a rod with required length and forming a head portion at one end of the rod. Then performing threading on an outer surface of the rod to form outer threads and carrying out heat treatment including quenching and tempering at 380° C.±50° C. to get a threaded rod. Next cutting a steel wire rod according to a length required to get a tube and forming a through hole axially penetrating the tube and corresponding to the threaded rod. Then forming a mounting portion at an outer edge of one end of the tube, carrying out optical heat treatment at 1100° C.±100° C., and performing electroplating to get an outer tube. Lastly the threaded rod is inserted into the through hole of the outer tube and the assembly is completed.

A method for producing a zinc or zinc-alloy coated steel sheet with a tensile strength higher than 900 MPa, for the fabrication of resistance spot welds containing in average not more than two Liquid Metal Embrittlement cracks per weld having a depth of 100 μm or more, with steps of providing a cold-rolled steel sheet, heating cold-rolled steel sheet up to a temperature T1 between 550° C. and Ac1+50° C. in a furnace zone with an atmosphere (A1) containing from 2 to 15% hydrogen by volume, so that the iron is not oxidized, then adding in the furnace atmosphere, water steam or oxygen with an injection flow rate Q higher than (0.07%/h×α), α being equal to 1 if said element is water steam or equal to 0.52 if said element is oxygen, at a temperature T≥T1, so to obtain an atmosphere (A2) with a dew point DP2 between −15° C. and the temperature Te of the iron/iron oxide equilibrium dew point, then heating the sheet from temperature T.sub.1 up to a temperature T.sub.2 between 720° C. and 1000° C. in a furnace zone under an atmosphere (A2) of nitrogen containing from 2 to 15% hydrogen and more than 0.1% CO by volume, with an oxygen partial pressure higher than 10.sup.−21 atm., wherein the duration t.sub.D of heating of the sheet from temperature T.sub.1 up to the end of soaking at temperature T.sub.2 is between 100 and 500 s., soaking the sheet at T.sub.2, then cooling the sheet at a rate between 10 and 400° C./s, then coating the sheet with zinc or zinc-alloy coating.

A method for producing a zinc or zinc-alloy coated steel sheet with a tensile strength higher than 900 MPa, for the fabrication of resistance spot welds containing in average not more than two Liquid Metal Embrittlement cracks per weld having a depth of 100 μm or more, with steps of providing a cold-rolled steel sheet, heating cold-rolled steel sheet up to a temperature T1 between 550° C. and Ac1+50° C. in a furnace zone with an atmosphere (A1) containing from 2 to 15% hydrogen by volume, so that the iron is not oxidized, then adding in the furnace atmosphere, water steam or oxygen with an injection flow rate Q higher than (0.07%/h×α), α being equal to 1 if said element is water steam or equal to 0.52 if said element is oxygen, at a temperature T≥T1, so to obtain an atmosphere (A2) with a dew point DP2 between −15° C. and the temperature Te of the iron/iron oxide equilibrium dew point, then heating the sheet from temperature T.sub.1 up to a temperature T.sub.2 between 720° C. and 1000° C. in a furnace zone under an atmosphere (A2) of nitrogen containing from 2 to 15% hydrogen and more than 0.1% CO by volume, with an oxygen partial pressure higher than 10.sup.−21 atm., wherein the duration t.sub.D of heating of the sheet from temperature T.sub.1 up to the end of soaking at temperature T.sub.2 is between 100 and 500 s., soaking the sheet at T.sub.2, then cooling the sheet at a rate between 10 and 400° C./s, then coating the sheet with zinc or zinc-alloy coating.

An object comprising a chromium-based coating on a substrate is disclosed. The chromium is electroplated from an aqueous electroplating bath comprising trivalent chromium cations, wherein the chromium-based coating comprises: a first chromium-containing layer, on the substrate, having a thickness of at least 100 nm, and a Vickers microhardness value of 700-1000 HV; a second chromium-containing layer, on the first chromium-containing layer, having a Vickers microhardness value that is at least 1.3 times higher than the Vickers microhardness value of the first chromium-containing layer, and a crystal size of 8-35 nm; and wherein the chromium-based coating exhibits a critical scratch load value (L.sub.c2) of at least 60 N in the adhesion test according to ASTM C1624-05 (2015; point 11.11.4.4), and wherein the chromium-based coating does not contain chromium carbide. Further is disclosed a method for its production.

A method for producing round stock (10) which is provided with at least one inscription and/or marking (16), at least the surface (12) of the round stock (10) consisting of a metallic material, in particular of chromium or steel, for example of hardened steel, chromium-plated steel or stainless steel. In order to improve this method such that disadvantages and shortcomings are avoided, the method includes the following steps: placing on the surface (12) at least one cover (20) which is adapted to the shape of the surface (12) and in particular has the inscription and/or marking (16), such that the region to be provided with the inscription and/or marking (16) is not covered by the cover (20),—exposing the round stock (10) to a first electrolyte (30) together with the cover (20), material being removed from the surface (12) by said electrolyte in the region to be provided with the inscription and/or the marking (16) while producing depressions (14), and—exposing the round stock (10) together with the cover (20) and the depressions (14) not covered by the cover (20) to a second electrolyte (32) by which the depressions (14) are filled to produce the inscription and/or marking (16) which differs from the surface (12) optically, in particular with respect to color. The present invention also relates to round stock (10) which is manufactured from a metallic material, with the round stock being provided with a correspondingly produced inscription and/or marking (16).

A method for producing round stock (10) which is provided with at least one inscription and/or marking (16), at least the surface (12) of the round stock (10) consisting of a metallic material, in particular of chromium or steel, for example of hardened steel, chromium-plated steel or stainless steel. In order to improve this method such that disadvantages and shortcomings are avoided, the method includes the following steps: placing on the surface (12) at least one cover (20) which is adapted to the shape of the surface (12) and in particular has the inscription and/or marking (16), such that the region to be provided with the inscription and/or marking (16) is not covered by the cover (20),—exposing the round stock (10) to a first electrolyte (30) together with the cover (20), material being removed from the surface (12) by said electrolyte in the region to be provided with the inscription and/or the marking (16) while producing depressions (14), and—exposing the round stock (10) together with the cover (20) and the depressions (14) not covered by the cover (20) to a second electrolyte (32) by which the depressions (14) are filled to produce the inscription and/or marking (16) which differs from the surface (12) optically, in particular with respect to color. The present invention also relates to round stock (10) which is manufactured from a metallic material, with the round stock being provided with a correspondingly produced inscription and/or marking (16).