Jfe Steel Corporation

Yoshitsugu Iijima

Hiroshi Sekine

Hiroshi Mizuno

Noritsugu Suzuki

Masatoshi Sugioka

Satoshi Ueoka

Kazuya Asano

Takeshi Chiba

Tomoyoshi Ogasahara

Yasuhiro Matsuki

Kiyoshi Nakano

Shuji Kuyama

Takahiko Ogura

Kazuya Ibuki

Hiroshi Shigeta

Yoshimitsu Fukui

Kei Mikami

A material-property-value estimating method of estimating a material-property-value of a target steel-strip product manufactured via at least one of a reheating process, a rolling process, and a cooling process, which are performed while a target material is being conveyed along a conveyance route, the material-property-value estimating method includes an estimating step of estimating a material-property-value of each of meshes dividing the target steel-strip product based on a measured value that has been measured once or more by a measuring device installed on the conveyance route, the measured value including at least a temperature of the target material; and a chemical composition per component of the target steel-strip product.

Material property value estimating method, material property value estimating device, and steel-strip manufacturing method

Provided are a cooling method and a cooling apparatus that, in the cooling of a hot-rolled steel strip, regulates the amount of cooling water in a two-stage manner for each set of headers in the width direction and changes the rate at which the steel strip is cooled, in a multistage manner by a simple method, and that is effective particularly in cooling the lower surface of the steel strip, where space is narrow. The spray nozzlesare arranged in a row in the width direction of the steel strip at a predetermined pitch. Two systems of cooling headersare arranged for one set so that spray nozzlesadjacent in the width direction can be supplied with cooling water from different pipe systems, and a spray valveis attached to each cooling headerso that spraying/stop of spraying of cooling water can be individually performed.

Method and apparatus for cooling hot-rolled steel strip

Provided is a metal strip for a pipe with which the weight of a pipe can be reduced while maintaining the strength of a joint portion that tends to be structurally the weakest. A metal strip L is formed by rolling. The thickness of each of a head end portionand a tail end portion, which are longitudinal end portions, is greater than the thickness of an intermediate portion excluding the longitudinal end portions. The metal strips are connected to each other in series by welding, and a pipe is made by performing a pipe-forming operation.

Metal strip

The present invention provides a method of manufacturing a steel product, comprising the step of heat treating a steel product having been subjected to quenching or accelerated cooling on a hot rolling line after hot rolling to pass the steel product through a plurality of induction heating apparatuses, which are installed on the hot rolling line, three times or more. The method of the present invention makes it possible to uniformly heat treat the steel product with high productivity.

Process for producing steel product and production facility therefor

A heat treatment apparatus includes a plurality of induction heating devices which heat a steel product, a correctional device which corrects the steel product, a computing device which computes supply predetermined electric power which is supplied to the induction heating device, on the basis of a size of the steel product, a conveying speed of the steel product, a heating target temperature of the steel product, and a predetermined temperature of the steel product at the previous stage of the induction heating devices, and a power supply unit which supplies the supply predetermined electric power computed by the computing device to the induction heating devices, and the computing device which computes electric power for uniform heating processing on the steel product or electric power for surface layer heating processing on the steel product.

Heat treatment apparatus, heat treatment method, medium on which heat treatment program is recorded, and steel product

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Tokyo, Japan

Yoshitsugu Iijima