Nippon Steel Corporation

Sony Corporation

Yujiro Miyauchi

Yoshio Shindo

Katsushi Saito

Toshimichi Murata

Takeshi Kubota

Hiroaki Kato

Kazuo Koyama

Joji Oka

Yoshio Shindou

Satoru Tanaka

Toshio Tanoue

Yasuharu Sakuma

Katsuhiko Kato

Atsushi Itami

Teruo Takeuchi

Fumio Yamazaki

Masaya Tsutsumi

Taketoshi Taira

Chohachi Sato

Itsuro Hiroshige

Yoshio Shindow

Wataru Hotta

Lubricative stainless steel sheet and pipe having a chromate film on at least one of the surfaces of a stainless steel sheet or pipe substrate, the chromate film having an amount of adhered Cr of 5 to 100 mg/m , and, on the chromate film, a lubricant film obtained by applying, on the chromate film, a water-base coating containing (a) a urethane resin of ether-ester type having a skeleton of bisphenol type, a skeleton of ester, and a carboxyl group, (b) an epoxy resin, and (c) a polyolefin wax, and baking the applied coating, the sum of the amount of the urethane resin of (a) and the epoxy resin of (b) being 70 to 95% by weight of the total solids of the coating, the amount of the polyolefin wax of (c) being 5 to 30% by weight of the total solids of the coating, and the lubricant film having a thickness of 0.5 to 5 micrometers and a Vickers hardness of at least 15. A method of producing a lubricative stainless steel pipe is also disclosed.

Lubricative stainless steel sheets and pipes and method of producing lubricative stainless steel pipes

Provided are a high strength cold rolled steel sheet and a high strength plated steel sheet possessing improved geomagnetic shielding properties, that is, having a high relative permeability in a d.c. magnetic field around 0.3 Oe, a process for producing the same, and an explosion-proof band or an outer magnetic shielding material, for television cathode-ray tubes, using the steel sheet. An ultra low carbon steel, which has a carbon content of not more than 0.0060% and has been subjected to solid solution strengthening utilizing silicon and magnesium without relying upon precipitation strengthening, is deoxidized with silicon so that aluminum is substantially absent in the steel. Alternatively, when the ultra low carbon steel is deoxidized with aluminum, boron is added to inhibit the precipitation of AlN. Next, the deoxidized steel is finish rolled at 750 to 980.degree. C., cold rolled with a reduction ratio of 60 to 90%, and then annealed in the temperature range of 750.degree. C. to the Ac.sub.3 point in a continuous annealing equipment or an in-line annealing type continuous galvanizing equipment to bring the ferrite grain diameter in the metallographic structure to 10 to 200 .mu.m.

High-strength cold rolled steel sheet and high-strength plated steel

Disclosed are a black surface-treated steel sheet, which comprises a steel sheet or plated steel sheet and a electrodeposited composite plating coating formed in a deposition amount of 0.1 to 5 g/m.sup.2 on the surface of the steel sheet or plated steel sheet, the plating coating containing metallic zinc or Zn--Ni alloy and oxides or hydrous oxides and sulfur compound, and a process for the preparation of a black surface-treated steel sheet, which comprises carrying out the electrolysis in an acidic aqueous solution containing Zn.sup.2+ and, as the main components, at least one member selected from the group consisting of Fe.sup.2+, Co.sup.2+ and Ni.sup.2+, and oxidative ion, and a thio compound, by electrolysis a steel sheet or plated steel sheet as the cathode, and water-washing and drying the treated steel sheet.

Black surface-treated steel sheet

Disclosed are a black surface-treated steel sheet, which comprises a steel sheet or plated steel sheet and a electrodeposited composite plating coating formed in a deposition amount of 0.1 to 5 g/m.sup.2 on the surface of the steel sheet or plated steel sheet, the plating coating containing metalic Zinc or Zn-Ni alloy and oxides or hydrous oxides and sulfur compound, and a process for the preparation of a black surface-treated steel sheet, which comprises carrying out the electrolysis in an acidic aqueous solution containing Zn.sup.2+ and, as the main components, at least one member selected from the group consisting of Fe.sup.2+, Co.sup.2+ and Ni.sup.2+, an oxidative ion, and a thio compound, by electrolysis a steel sheet or plated steel sheet as the cathode, and water-washing and drying the treated steel sheet.

Process for the preparation of a black surface-treated steel sheet

A weldable steel plate plated with zinc, a zinc base alloy or zinc composite and coated on the plating with a coating material comprising a mixture of at least one type of ferrous alloy powder with an oxygen concentration of 1.0% by weight or less and zinc dust, is provided, and the weldable coated steel plate also has good workability, coherence, weldability and corrosion resistance.

Anticorrosive weldable coated steel

A steel strip having an excellent phosphate-coating property is produced by subjecting at least one surface of the steel strip to electrolytic treatment in which the steel strip serves as an anode and the steel strip surface is brought into contact with an aqueous solution containing at least one phosphate selected from the group consisting of alkali metal phosphates and ammonium phosphate and having a concentration of phosphoric anions of 0.05 mole/l or more and a pH of from 4 to 7, at an anode current density of 2 A/dm.sup.2 or more, to an extent that a phosphate surface layer is formed in an amount of 0.0001 to 0.05 g/m.sup.2 on the metal strip surface.

Method for producing a steel strip having an excellent phosphate-coating

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Kimitsu, Japan

Yujiro Miyauchi