Nippon Kokan Kabushiki Kaisha

Akira Tonouchi

Toshio Ishii

Shuzo Fukuda

Hiroshi Kagechika

Takeshi Adaniya

Tomihiro Hara

Roland Kammel

Yutaka Ohkubo

Masaru Sagiyama

Tatsuro Anan

Hiroshi Miwa

Toshio Kaneko

The invention provides a Cr alloy plating bath comprising a sulfate bath consisting essentially of divalent Cr ion and trivalent Cr ion in a total amount of between 1.5 to 2.0 mol/l, cation of one or more than two selected from the group consisting of potassium ion, sodium ion and ammonium ion in a total amount of 1.5 to 2.5 mol/l, and metal ion of one or more than two selected from the group consisting of Fe, Ni and Co, in an amount of less than 0.6 mol/l, wherein the invention provides stable plating, without requiring a separation between electrolytes with a diaphragm, and provides good deposition at high current efficiencies.

Method of electrodepositing a chromium alloy deposit

A vertical type electro-galvanizing apparatus, which comprises: a U-shaped electro-galvanizing tank including a first vertical path (12) at a steel strip inlet side, a second vertical path (13) at a steel strip outlet side and a horizontal path (14) for communicating the lower end of the first vertical path (12) to the lower end of the second vertical path (13); a first conductor roll (2), arranged above the first vertical path (12), for directing a steel strip (5) downwardly into the first vertical path (12) and applying electricity to the steel strip (5); at least one sink roll (3, 3'), arranged in the horizontal path (14), for upwardly reversing the travelling direction of the steel strip (5); a second conductor roll (4), arranged above the second vertical path (13), for directing the steel strip (5) upwardly from the second vertical path (13) and applying electricity to the steel strip (5); at least one first electrode plate (6, 6) arranged in the first vertical path (12); at least one second electrode plate (7, 7) arranged in the second vertical path (13); an electro-galvanizing solution supply pipe (17) arranged at a top portion (15) of the first vertical path (12) and/or a top portion (16) of the second vertical path (13); and at least one electro-galvanizing bath discharge pipe (18) arranged at the top portion (15) of the first vertical path (12) and/or the top portion (16) of the second vertical path (13).

Vertical type electro-galvanizing apparatus

A strip horizontally travels within an electroplating apparatus while the plating solution is applied between the strip and anode, in which relative speed of the solution to the strip and/or current density are varied, whereby an outer plated layer on the strip is provided with Fe-Zn alloy of high Fe content while an inner plated layer on the strip is provided with Fe-Zn alloy of low Fe content.

Method of Fe-Zn alloy electroplating

Disclosed is a method for electroplating a steel strip by arranging a plurality of electrode rows each consisting of a plurality of electrodes disposed adjacent to each other along the direction of width of said steel strip in opposition to said strip travelling in an electrolytic cell holding an electrolytic solution, so that a metal constituting said electrodes may be electroplated on said steel strip, comprising the steps of intermittently or continuously transferring said electrodes of said electrode rows in a direction perpendicularly to the direction of travel of said steel strip at a speed so that a distribution of a deposition amount of the metal of said electrodes along the direction of width of said steel strip may be kept within an allowable tolerance, a width of said electrode rows being greater than the width of said steel strip; and unloading said electrode from one end of one of said electrode rows transferred by said transferring step and loading said electrode to the other end of said one electrode row or to an end of another of said electrode rows.

Method for electroplating steel strip

Growing community of inventors

Tokyo, Japan

Akira Tonouchi