The invention relates to the field of cold rolling, in particular to a control method of part-strand-truncated rolling of an automatic system of a five-stand cold continuous rolling unit. In the cold continuous mill automatic system, the most important function of a two-stage computer is to calculate preset definite values and parameters needed by control of a one-stage PLC system according to hot rolled steel roll PDI data, machine and mill characteristic parameters and production plans, and the one-stage PLC system sends the setting values to all basic automation control units in real time according to the strip steel trace function, and preset control over the unit is completed; and the following set values will be given out and include rolling reduction of all stands, rolling force, roll seam values, relative speed values of all stands, main order speed values, setting values of tension between all stands, roll bending force setting values of all stands, roll channeling position setting values of all stands, cooling dosage setting and other auxiliary equipment setting values, and FGC setting calculation is carried out in the dynamic schedule change rolling period. In this way, the mill automatic system has the higher flexibility, safety and reliability.

Control method of part-strand-truncated rolling of automatic system of five-stand cold continuous rolling unit

The invention discloses a method for preventing thin strip steel from being fractured at the start moment. The method is applied to a cold continuous rolling unit. The method comprises the steps thatrolling force, formed at the stop moment, of the cold continuous rolling unit is acquired as memory rolling force; then, when roller replacement of the cold continuous rolling unit is completed and each roller gap is in the opened state, current winding tension corresponding to the start moment is determined, wherein the current winding tension is 1.5-3 times set winding tension, and furthermore,the covering phenomenon of a rolling mill section can be eliminated; and in addition, corresponding current actual rolling force, formed at the start moment, of each rack of the cold continuous rolling unit is determined based on the memory rolling force, and each rack of the cold continuous rolling unit is controlled to conduct downwards-pressing according to the corresponding current actual rolling force, formed at the start moment, of each rack, wherein the current actual rolling force of the first rack, the current actual rolling force of the second rack, the current actual rolling force of the third rack and the current actual rolling force of the fourth rack of the cold continuous rolling unit each accounts for 90-95% of the memory rolling force. By means of the method, the strip steel can be prevented from being fractured due to the excessively-large rolling force, thus strip fracturing of a rolling mill is avoided, and the cold continuous rolling unit is controlled to be started.

Method for preventing thin strip steel from being fractured at start moment

The invention relates to a method for comprehensively optimizing a clearance amount and an overlap amount in the shearing process of a band steel. The method mainly comprises the following executing steps of: 1, collecting field product parameters; defining optimal overlap amount search related parameters; 3, defining optimal clearance amount search related parameters; 4, calculating a clearance amount influence coefficient; 5, calculating a clearance set variable of band steel trimming; 6, calculating an overlap amount influence coefficient; 7, calculating an overlap amount set variable; 8, carrying out field experimentation and quality evaluation; 9, determining whether to meet a lower limit of a quality requirement of a client; 10, calculating a trimming comprehensive quality function; 11, calculating a comprehensive quality evaluation function; 12, outputting optimal process parameters. The method can meet different requirements of different downstream users for trimming quality, and meanwhile, considers influence of a steel type on trimming quality; according to field experiments, an overlap amount and a clearance amount in trimming field are subjected to optimized setting; the control management level of trimming quality is improved.

Method for comprehensively optimizing clearance amount and overlap amount in shearing process of band steel

The embodiment of the invention discloses a starting method of a cold tandem rolling mill for high-strength steel. The starting method comprises the steps that a tension value is preset at an outlet of the cold tandem rolling mill; roll forces of a first rack, a second rack, a third rack, a fourth rack and a fifth rack are respectively adjusted to respective preset values; a tension value is preset at an inlet of the cold tandem rolling mill, and the cold tandem rolling mill is started; inclined values of hydraulic cylinders between the racks are adjusted; when tension values of each of the racks are stabilized, whether the difference value between the thickness of high-strength steel of an outlet of the fifth rack and the target thickness is greater than a preset difference value or not is judged; the roll forces from the first rack to the fourth rack are adjusted if the difference value between the thickness of high-strength steel and the target thickness is greater than the preset difference value, so that the difference value is less than the preset difference value; and the cold tandem rolling mill is operated to produce the high-strength steel based on a preset speed. The starting method of the cold tandem rolling mill for high-strength steel solves the problem that starting failure exists due to the difficult control over the roll force in the prior art.

Starting method of cold tandem rolling mill for high-strength steel

The invention discloses a dynamic specification-changing moving method for working rollers of a cold continuous mill. When the length L between a weld of a current roll of strip steel and the next roll of strip steel and a first rack is equal to t (1).V , the working roller of the first rack starts to move from the current position to the set moving position of the working roller of the next roll of strip steel. When the length L between the weld of the current roll of strip steel and the next roll of strip steel and the first rack is equal to [t (2).V -L ]H /H , the working roller of a second rack starts to move from the current position to the set moving position of the working roller of the next roll of strip steel. When the length L between the weld of the current roll of strip steel and the next roll of strip steel and the first rack is equal to [t (3).V -L ]H /H , the working roller of a third rack starts to move from the current position to the set moving position of the working roller of the next roll of strip steel. By means of the dynamic specification-changing moving method, the control precision for thinning of edges of the head and tail of the strip steel can be guaranteed, and the strip steel is prevented from being broken in the positions of welds.

Dynamic specification-changing moving method for working rollers of cold continuous mill

The invention discloses a raw material plate starting method of a cold rolling mill. When a first starting signal related to starting in a raw material plate starting mode is received, the roll bending force of each rack in a rack group is loaded to a roll bending force set value, and the compacting and rolling force of the cold rolling mill is loaded to a rolling force set value; when a second starting signal is received after the first starting signal, the real time rolling mill speed of the cold rolling mill is increased at a constant speed to a first set speed value; when that the real time rolling mill speed reaches a preset critical speed value is detected, whether tensions between the racks are stable or not is judged, and whether strip steel thickness deviations are stable or not is judged; and when the tensions between the racks and the strip steel thickness deviations are all stable, the rolling mill speed of the cold rolling mill is increased to a second set speed value from the first set speed value. The raw material plate starting method provided by the invention solves the problem of starting difficulty caused when all racks are started at the same time, further the loss due to waste products is reduced, and the yield is effectively improved.

Raw material plate starting method for cold rolling mill

The invention discloses a control method for a tandem cold mill. The control method comprises the following steps: obtaining history optimal CVC setting data; fitting strip steel specification parameters, mill parameters of the tandem cold mill and the history optimal CVC setting data to obtain a CVC channeling roll value of the tandem cold mill; comparing the CVC channeling roll value with a channeling roll set value of a mill secondary system of the tandem cold mill; if a deviation absolute value between the CVC channeling roll value and the channeling roll set value is greater than a preset deviation threshold value, receiving a manual amendment value and carrying out self-learning, based on the manual amendment value, on the CVC channeling roll value to obtain a self-leaned CVC channeling roll value; and at least carrying out strip steel rolling, according to the self-learned CVC channeling roll value, on a hot rolling raw material by virtue of the tandem cold mill. The control method avoids deviation and strip breakage caused by great channeling roll value setting deviation, reduces the probability that a tandem cold mill set has deviation and strip breakage, and relieves the technical problem that the tandem cold mill set in the prior art frequently has deviation and strip breakage, so that the yield and the product quality of the tandem cold mill set are improved.

Control method for tandem cold mill

The embodiment of the invention provides a rolling parameter optimization method and device, for improving the rolling precision of high-strength strip steel. The method includes the following steps:determining a steel grade to which a steel type belongs; calculating the simulated rolling force corresponding to the steel type based on the steel grade to which the steel type belongs; acquiring theactual rolling force of the steel type during actual production; and determining a parameter optimization strategy based on the simulated rolling force and the actual rolling force.

Rolling parameter optimization method and device

The invention discloses a control method for improving belt breakage in the flying gauge change process, and belongs to the technical field of rolling. The control method includes the steps of controlling the length of a wedge-shaped section in the flying gauge change process so as to ensure the stable control over the tension and thickness, controlling the position of a weld joint in the flying gauge change process so as to prevent belt breakage from occurring in the flying gauge change process, controlling the tension between machine frames in the flying gauge change process so as to prevent belt breakage from occurring in the flying gauge change process, and controlling the cutting crescent in the flying gauge change process so as to make a front rolled steel strip and a rear rolled steel strip smoothly transferred on the sides of the weld joint. By means of the control method, the belt breakage problem frequently occurring in the flying gauge change process is solved, the shutdown time is shortened, the stable production of a production line is promoted, and the work efficiency is greatly improved.

Wang Fei

Papers

Raw material plate starting method for cold rolling mill

Control method for tandem cold mill

Rolling parameter optimization method and device

Method for preventing thin strip steel from being fractured at start moment

Control method for improving belt breakage in flying gauge change process