Nippon Steel Corporation

Katsuyoshi Yoshida

Hisashi Takahashi

Motohiro Nakayama

Tatsuya Kanamaru

Mitsuo Higashi

Kenzi Koyama

Satoshi Hanai

Yukio Kitajima

Zyun-Ichi Morita

A method of and an apparatus for overaging treatment of low melting point-metal plated steel band, in which a hearth roll having surface layer which consists mainly of phenol resin, mineral fiber and small quantity of additive as necessary is used under the overaging treatment temperature range and within weak oxidation, inactive or reducing high temperature gas atmosphere such that the phenol resin substantially does not oxidize and evaporate. The method and apparatus allow overaging treatment of low melting point-metal plated steel band in continuous annealing furnace having many hearth rolls to guide the steel band, and prevent the low melting point metal from being picked up on the surface of the hearth roll.

Method for heat treatment of low melting point-metal plated steel band

A plating chamber holds a reducing or inert atmosphere heated to a temperature suited for plating or galvanizing. A pair of power-driven coating rolls are horizontally disposed in the plating chamber, one roll contacting the top surface of a metal strip to be plated and the other contacting the bottom surface. A molten coating metal is continuously supplied so as to form a uniform film of the metal on the peripheral surface of each coating roll. By means of deflector rolls horizontally disposed in the plating chamber, a metal strip heated to a temperature suited for plating continuously travels through the chamber. A surface of the strip becomes plated on contacting the peripheral surface of the coating roll on which the film of the molten coating metal has been formed. The coating rolls can be drawn away from the surface of the strip by shifting the deflector or coating rolls, so that plating can be applied to one, both or neither side of the strip as desired.

Method for applying coating of molten metals

A method of continuous galvanizing a steel strip partially or one side, which comprises applying silicone resin to a part or on one side of the steel strip which is to be left non-plated in a subsequent continuous molten zinc coating, baking the silicon resin coated steel strip at a temperature ranging from 300 to 800.degree. C in an oxidizing atmosphere, and subjecting the steel strip to heat treatment in a reducing atmosphere and introducing the heat treated steel strip to a zinc coating bath.

Method of continuous galvanizing steel strip on partial or one side

A surface treated steel sheet and strip having a surface layer of M-Si-R in which M is at least one of the group consisting of chromium, phosphorus, silicon, cobalt, manganese, copper, nickel, aluminum and titanium, and R is a group of atoms which has 2 to 10 carbon atoms and contains one or more functional groups selected from the group consisting of vinyl, epoxy, acryl and amino groups.

Growing community of inventors

Tokai, Japan

Katsuyoshi Yoshida