Kawasaki Steel Corporation

Kabushiki Kaisha Toshiba

Nobuaki Nomura

Hideyuki Nikaido

Toshisada Takechi

Yoshimitsu Fukui

Yoshito Goto

Tomoyuki Tezuka

Yoshiharu Anbe

Norio Takashima

Katsuhiro Takebayashi

Kunio Isobe

Masanori Kitahama

Yoshikiyo Tamai

Hiroshi Shishido

Noriyasu Okitani

Taichi Hatashita

Yoshiaki Kaneda

Hideyuki Yuzawa

Kenji Kataoka

A method and apparatus for continuously finishing hot-rolling steel strips include partially joining a rear end of a preceding steel strip and a leading end of a succeeding steel strip after the strips have passed through a rough hot-rolling step. The joint is flattened. The joint is rolled with a first stand of a tandem rolling mill. The mill is provided with a plurality of stands that includes a pair of work rolls and backup rolls and/or intermediate rolls, so that a compression stress acts at the unjointed section of the strips in the longitudinal direction of the joint while tracking the joint. Shape-control-rolling is performed on the joint with a second and succeeding stands so that a section of the steel strip other than the joint is subjected to the shape-control-rolling at all the stands.

Method and apparatus for continuous finishing hot-rolling a steel strip

In the continuous rolling mills, the strip crown and the strip flatness of a strip can be controlled to any desired value. In the strip crown measuring method, the strip crown of the first stage rolling mill can be obtained by adding the set target strip crown value and a value obtained by multiplying the deviation in mechanical strip crown between the predicted value and the actually measured value by a imprinting ratio. Further, the strip crowns of the second and after rolling mills can be obtained by adding the set target strip crown, a value obtained by multiplying the deviation in mechanical strip crown between the predicted value and the actually measured value by a imprinting ratio, and a value obtained by multiplying the deviation in entry strip crown between the target value and the calculated measurement value by an inheritance coefficient, for each rolling mill. Further, in the control method of the continuous rolling mills, the rolling mill is controlled in correspondence to the deviation in strip crown between the value actually measured by the profile gauge and the previously calculated value, in such a way that the manipulated variables of the actuators of the rolling mills arranged on the upstream side of the rolling mill having the profile gauge are equal to each other or determined to a predetermined proportion by use of imprinting ratios and inheritance coefficients.

Strip crown measuring method and control method for continuous rolling

A sheet crown control method and apparatus for use in endless rolling in which consecutively fed sheets are joined to each other to be continuously rolled through a rolling equipment line. The rolling equipment line includes a junction device for joining consecutively fed sheets to each other, a plurality of stands arranged in tandem on the downstream side of the junction device and having a roll bender load adjusting mechanism and a roll crossing mechanism. The roll cross angle of rolls incorporated in a stand of each rolling mill is set at a predetermined value beforehand if there is a roll cross angle that will enable a target sheet crown to be applied to each sheet and the roll bender load of each stand is adjusted on-line, thereby effecting sheet crown control. Rolling also may be performed while adjusting the roll cross angle of rolls incorporated in stands of each rolling mill on-line together with the roll bender load. The roll bender load and the roll cross load may be adjusted in a transition region where a junction between sheets exists or in a stationary region where sheets of the same material follow one after another.

Sheet crown control method and rolling equipment line for endless rolling

The sheet profile of a strip on the outlet side of a final stand coincides with a desired value without deforming the shape of the strip, by using a hot strip finish rolling mill having a number of rolling stands disposed sequentially. The rolling mill employs feedback control of upstream stands to reduce the error between a sheet profile measured by a sheet profile meter disposed at the outlet side of a selected stand and a desired sheet profile. The selected stand is the stand where the sheet thickness of the strip is at the percentage sheet crown critical sheet thickness. The sheet profile measured by the sheet profile meter is used to control the downstream stands using feed-forward control to make the sheet profile on the outlet side of the final stand coincide with the desired sheet profile.

Method and apparatus for controlling rolling process in hot strip finish

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Chiba, Japan

Nobuaki Nomura