The present invention relates to a method for producing hot rolled strip steel, especially the producing method of hot rolled strip steel with multiple target thicknesses in the longitudinal direction. It is a method to produce the strip steel with different target thicknesses in the longitudinal direction by using a hot continuous rolling mill. In this method, the first equal-thickness section of the strip steel is controlled with the conventional thickness control strategy, while other equal-thickness sections and the transition section between equal-thickness sections are controlled with the variable-thickness control strategy. Under the variable-thickness control strategy, the length of the first section of strip steel, the variation of thickness target value, the rolling stability and the spacing between stands are combined to determine the stand participating in the variable-thickness control, and calculate the roller gap value, as well as the time and speed of the variation of roller gap, thus achieving the producing control of strip steel with different target thicknesses in the longitudinal direction. The present invention utilizes the length of the first equal-thickness section and the variation of different target thicknesses and other related factors to determine the stands participating in the control, and then distributes the load variation among the stands, thus effectively avoiding the influence on the rolling stability due to imbalance of second flow, so that the produced strip with variable thickness in different sections in the longitudinal direction meet the user's requirements.

The present invention relates to a method for producing hot rolled strip steel, especially the producing method of hot rolled strip steel with multiple target thicknesses in the longitudinal direction. It is a method to produce the strip steel with different target thicknesses in the longitudinal direction by using a hot continuous rolling mill. In this method, the first equal-thickness section of the strip steel is controlled with the conventional thickness control strategy, while other equal-thickness sections and the transition section between equal-thickness sections are controlled with the variable-thickness control strategy. Under the variable-thickness control strategy, the length of the first section of strip steel, the variation of thickness target value, the rolling stability and the spacing between stands are combined to determine the stand participating in the variable-thickness control, and calculate the roller gap value, as well as the time and speed of the variation of roller gap, thus achieving the producing control of strip steel with different target thicknesses in the longitudinal direction. The present invention utilizes the length of the first equal-thickness section and the variation of different target thicknesses and other related factors to determine the stands participating in the control, and then distributes the load variation among the stands, thus effectively avoiding the influence on the rolling stability due to imbalance of second flow, so that the produced strip with variable thickness in different sections in the longitudinal direction meet the user's requirements.

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.

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.

Methods and apparatus to determine a plunge depth position of material conditioning machines are disclosed. An example method for setting a plunge depth of a leveler includes incrementally adjusting, via an actuator, a first work roll relative to a second work roll between a plurality of incremental plunge depth positions; measuring a pressure value in the actuator at the respective incremental plunge depth positions; associating the measured pressure values with the corresponding incremental plunge depth positions; detecting a smallest one of the measured pressure values; and identifying a first one of the incremental plunge depth positions corresponding to the smallest one of the measured pressure values.

Methods and apparatus to determine a plunge depth position of material conditioning machines are disclosed. An example method for setting a plunge depth of a leveler includes incrementally adjusting, via an actuator, a first work roll relative to a second work roll between a plurality of incremental plunge depth positions; measuring a pressure value in the actuator at the respective incremental plunge depth positions; associating the measured pressure values with the corresponding incremental plunge depth positions; detecting a smallest one of the measured pressure values; and identifying a first one of the incremental plunge depth positions corresponding to the smallest one of the measured pressure values.

A roller cage for a profiling line, comprising: a support frame (F1) that entirely delimits a non-operating area (A1) which is external to the line; at least a motor (11) provided with a spindle (12) protruding externally of the non-operating area (A1); at least a shaped roller (13, mounted directly on the spindle (12) and arranged inside an operating area (B) of the line.

A method for altering the width of a strip-shaped rolled material (5), before, during or after hot rolling the rolled material in a hot rolling mill. The problem is to specify a method for altering width so that the length of a rolled out transition piece lying outside width tolerances can be reduced. Scrap losses are to be reduced. The crown of at least one working roll and/or at least one backing roll of a stand (7) is set as a function of a width error e=B−B between a setpoint width B.sub.setp and the width B of the rolled material (5), wherein the crown is increased when e>0 and the crown is reduced when e<0. AA R.sub.crown BB B.sub.setp.

A method for altering the width of a strip-shaped rolled material (5), before, during or after hot rolling the rolled material in a hot rolling mill. The problem is to specify a method for altering width so that the length of a rolled out transition piece lying outside width tolerances can be reduced. Scrap losses are to be reduced. The crown of at least one working roll and/or at least one backing roll of a stand (7) is set as a function of a width error e=B−B between a setpoint width B.sub.setp and the width B of the rolled material (5), wherein the crown is increased when e>0 and the crown is reduced when e<0. AA R.sub.crown BB B.sub.setp.

A provisional elongation strain difference distribution Δε(x) of a metal strip during rolling is found under conditions in which out-of-plane deformation of the metal strip is restrained. A critical buckling strain difference distribution Δε.sub.cr(x) is found based on the provisional elongation strain difference distribution Δε(x), a strip thickness and strip width of the metal strip, and tension acting on the metal strip at exit from a rolling mill. In cases in which the provisional elongation strain difference distribution Δε(x) exceeds the critical buckling strain difference distribution Δε.sub.cr(x), the difference between the provisional elongation strain difference distribution Δε(x) and the critical buckling strain difference distribution Δε.sub.cr(x) is found, and this difference is added to the provisional elongation strain difference distribution Δε(x) to find a true elongation strain difference distribution Δε′(x). Rolling conditions are set based on the true elongation strain difference distribution Δε′(x), and the metal strip is rolled, thereby controlling the profile of the metal strip.