Kawasaki Steel Corporation

Mitsubishi Jukogyo Kabushiki Kaisha

Naohiko Soeda

Kuniaki Sato

Norio Ohta

Yasuhisa Nakajima

Kenichi Yanagi

Kusuo Furukawa

Takeo Fukushima

Masahiro Harada

Koichi Hashiguchi

Yoshio Nakazato

Tomoo Tanaka

Atsushi Nagashima

The present invention relates to method and apparatus for heating a strip of metallic material in a continuous annealing furnace and more particularly to an improvement relating to a method and apparatus for heating a strip of metallic material in a continuous annealing furnace in which annealing of the strip is continuously carried out in such a manner that a gas serving to adjust temperature of the strip, is blown toward the strip through a plurality of gas jet nozzles which are arranged on one side or both sides of the strip, wherein the temperature and flow rate of the strip are properly determined to a required level in response to the changing of the operating conditions such as the heat cycle, line speed, thickness of strip, width of strip and the like. Further, the present invention relates to a method and apparatus for heating a strip of metallic material in a continuous annealing furnace, wherein the temperature of the strip is controlled to reach a target temperature by heating or cooling the strip by means of a gas jet or the like having excellent respondency at a part of the heating zone in the continuous annealing furnace whereby irregular annealing of the strip is effectively inhibited.

Method and apparatus for heating a strip of metallic material in a

The present invention relates to method and apparatus for heating a strip of metallic material in a continuous annealing furnace and more particularly to an improvement relating to a method and apparatus for heating a strip of metallic material in a continuous annealing furnace in which annealing of the strip is continuously carried out in such a manner that a gas, serving to adjust temperature of the strip, is blown toward the strip through a plurality of gas jet nozzles which are arranged on one side or both sides of the strip, wherein the temperature and flow rate of the strip are properly determined to a required level in response to the changing of the operating conditions such as the heat cycle, line speed, thickness of strip, width of strip and the like. Further, the present invention relates to a method and apparatus for heating a strip of metallic material in a continuous annealing furnace, wherein the temperature of the strip is controlled to reach a target temperature by heating or cooling the strip by means of a gas jet or the like having excellent respondency at a part of the heating zone in the continuous annealing furnace whereby irregular annealing of the strip is effectively inhibited.

A method and an apparatus for continuously annealing cold rolled steel strips successively passing through a preheating zone, a low temperature heating zone, a high temperature heating soaking zone, a primary cooling zone and a secondary cooling zone. In each zone, the steel strip is driven by hearth rolls alternately upward and downward in a serpentine path. According to the invention, in a high temperature zone such as the high temperature heating zone and the primary cooling zone where the steel strip is prone to heat buckling, the steel strip is caused to pass only once in a single direction without passing along the serpentine path, thereby preventing meandering and heat buckling of the steel strip.

Continuous annealing method and apparatus for cold rolled steel strips

High tensile strength steel sheets having high press formability and excellent shape-fixability in which an average roughness in surface Ha is 0.4-1.8 .mu.m, PPI value is more than 80 at a cut off level of 0.5 .mu.m, the proportional limit stress is less than 20 kg/mm.sup.2 and the microstructure consists of ferrite grains dispersed with fine martensite islands, are produced by cold rolling a hot rolled steel sheet containing 0.005-0.15% of carbon, and manganese, if necessary boron, molybdenum, chromium, silicon, nickel and copper within a range of 0.27-3% of Mneq. shown by the following formula (1)

High tensile strength steel sheets having high press-formability and a

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Chiba, Japan

Naohiko Soeda