scholarly journals Method for calculation the modes of strips cold rolling on multiple-stand rolling mill ensuring cost reduction of sheet rolling shop production. Report 1

2019 ◽  
Vol 62 (7) ◽  
pp. 511-516
Author(s):  
A. I. Bozhkov ◽  
D. A. Kovalev ◽  
V. S. Potapov ◽  
R. I. Shul’gin
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Surface Defects ◽  
Optimization Method ◽  
Rolling Process ◽  
Optimization Criterion ◽  
Operating Conditions ◽  
Sheet Rolling ◽  
Advantages And Disadvantages ◽  
Conditional Optimization

A method for calculating the modes of strips cold rolling on multiple-stand (reversing) rolling mill is considered providing minimum power consumption with maximum process stabilization at high speeds and obtaining the given quality of cold-rolled strips (minimum probability of surface defects, compliance with thickness tolerances and flatness requirements of the used standards). The problem is solved using the conditional optimization method. As an optimization criterion, it is proposed to use the total energy expenditure spent on the rolling process, as conditions – technological and structural limitations on the rolling parameters and conditions of strips stability to breaks and surface defects formation. The decision to develop this innovative method is due to the fact that a large number of existing approaches to calculation and design of rolling modes have visible advantages and disadvantages. In many cases, the researchers are trying to take into account several requirements that ensure stability of rolling process, its quality, the equipment operating conditions, reduction of energy consumption, metal, auxiliary materials and the specified (maximum) mill productivity. However, some of these requirements can be contradictory and the best one will be the mode that with a high degree of probability guarantees the fulfillment, in a certain proportion, of the entire set of requirements. Therefore, such calculation method is the presented in this article. Calculation of the cold rolling regimes was limited to selection and distribution of the crimping along the cages (passages in the reversing mill). Also, the strip strains are selected in the intercellular spaces, on the decoiler and coiler, and in setting the speed wedge in a particular system of constraints imposed on the input and output process variables as a function of the adopted optimality criterion. As it was noted earlier, the problem was solved with the help of the conditional optimization method with specification of the optimization criterion.

scholarly journals METHOD FOR CALCULATION THE MODES OF STRIPS COLD ROLLING ON MULTIPLE-STAND ROLLING MILL ENSURING COST REDUCTION OF SHEET ROLLING SHOP PRODUCTION. REPORT 2. AN EXAMPLE OF THE METHOD PRACTICAL USE ON FOUR-STAND ROLLING MILL 1400

2019 ◽  
Vol 62 (9) ◽  
pp. 667-673
Author(s):  
A. I. Bozhkov ◽  
D. A. Kovalev ◽  
V. S. Potapov ◽  
R. I. Shul’gin
Keyword(s):  
Energy Consumption ◽  
Cold Rolling ◽  
Rolling Mill ◽  
Surface Defects ◽  
Specific Energy Consumption ◽  
Optimization Method ◽  
Rolling Process ◽  
Rolling Speed ◽  
Total Energy Consumption ◽  
Sheet Rolling

The second part of the paper describes the method practical use on four-stand rolling mill 1400. When rolling the chosen typical sizes, the task was to determine the specific rolling mode, which will ensure a minimum of the total specific energy consumption at the maximum rolling speed, maximum process stabilization (minimum breaks, idle times, etc.) and obtaining the specified quality of the rolled strips (no surface defects, meeting the thickness and flatness requirements). It was achieved by including the above requirements in the constraint system with respect to the determined rolling modes for the selected strip sizes. For example, ensuring a given (maximum) performance for a specific size and brand of a strip is equivalent to realizing a gi673 ven (increased) rolling speed in the absence of unscheduled downtime occurring in emergency situations (in particular, in strip breaks). The speed limit depends on the power of engines, which is included in the complex of structural and technological limitations. The obtained examples, given in the article, have shown that the use of the method leads to fulfillment of all the specified requirements, which, in turn, ensures a reduction in production cost and an increase in the mill’s productivity. The calculation of the cold rolling modes was reduced to selection and distribution of the crimping along the stands (passages – in the reversible mill) and to a choice of specific strip tension in the interstand spaces, on decoiler and coiler, and in setting the wedge of speeds in a particular system of constraints imposed on the input and output process variables as a function of the adopted optimality criterion. The task was solved using the conditional optimization method, through the specification of the optimization criterion. As such criterion, the total energy consumption of the rolling process was used, as requirements – technological and design constraints on the rolling parameters and conditions for strip stability to breaks and to formation of rolls surface defects (“brews”, “chippings”, etc.), as well as to strip breaks.

Thickness Indirect Measurement Method for Direct Pulling Pilot Cold Rolling Mill

2011 ◽  
Vol 189-193 ◽  
pp. 2670-2674
Author(s):  
Zhi Jie Jiao ◽  
Chun Yu He ◽  
Jian Ping Li ◽  
Xiang Hua Liu
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Measurement Method ◽  
Rolling Process ◽  
Indirect Measurement ◽  
Cold Rolling Mill ◽  
Movement Data ◽  
Program Flow ◽  
New Type ◽  
Exit Speed

Pilot cold rolling mill is the important tool for the cold rolling process researching and new steel grade development. According to the design of the new type direct pulling pilot cold rolling mill, based on the mass flow constant principle, strip exit thickness indirect measurement method is studied. During rolling, strip entry and exit speed can be calculated accurately according to the measured value of two sides’ clamps movement. Data filtering treatment is adopted and program flow chart is designed. Based on the material entry thickness measured manually, exit thickness of all passes can be measured indirectly. This thickness indirect measurement method has been applied successfully on the new type pilot cold rolling mill, and the measurement results show that this method has a good accuracy.

scholarly journals IMPROVING DYNAMIC REGIME OF ROLLING FOR INCREASING DURABILITY OF BALL-ROLLING MILL ROLLS

2019 ◽  
Vol 61 (12) ◽  
pp. 927-932 ◽  
Author(s):  
V. Yu. Rubtsov ◽  
O. I. Shevchenko ◽  
M. V. Mironova
Keyword(s):  
Contact Pressure ◽  
Rotational Speed ◽  
Rolling Mill ◽  
Experimental Studies ◽  
Rolling Process ◽  
Operating Conditions ◽  
Frequency Method ◽  
Rolling Mills ◽  
Ball Rolling ◽  
Progressive Technology

One  of  the  important  reasons  for  the  downtime  of  ball  rolling  mills  is  replacement  of  rolls  due  to  their  wear  and  tear.  The  degree  and  zones  of  critical  wear  of  ball  rolling  rolls  are  investigated  in  the  article, where the greatest wear is observed over the flanges in zone of billet  capture.  Conditions  necessary  to  capture  the  blank  and  to  perform  rolling  process  are  analytically  determined.  Variable  frequency  method  of  roll  rotations  is  proposed  as  a  progressive  technology  for  blank supply. The results of tests for its variations in accordance with  linear  and  quadratic  law  are  presented.  Known  formulas  determining  average  strain  rate  at  rolls  rotational  speed  change  are  converted  for  linear and quadratic dependences. Experimental studies have been carried  out  in  conditions  of  EVRAZ  Nizhnetagilsky  Metallurgical  Plant  ball rolling mills during rolling of 60mm ball made of Sh-3G steel. Experiments  were  performed  for  given  parameters  of  manual  change  in  rolls rotation speed at blank capture by rollers. The results have shown  a  significant  effect  of  change  in  rotational  speed  on  average  specific  pressure during blank capture. Evaluation of torque-time and average  contact  pressure  for  calculated  and  experimental  data  are  presented.  Empirical characteristics are also described at variable rotational speed  of rolls according to linear and quadratic law. Acceptable convergence  of results of calculated and empirical characteristics is determined. Engineering solution has been proposed for that task. It consists in installation of a thyristor converter. This solution allows reduction of rolls  speed before blank capture. Also, this solution will increase frequency  to  the  nominal  value  according  to  the  given  law  after  blank  capture.  As an obtained result, there is uniform distribution of average contact  pressure over the entire length of the roll under different operating conditions  of  mill  in  automatic  mode. Application  of  this  technique  will  reduce wear degree of the rolling tool. At the same time, productivity  of ball rolling mill will be maintained. Rolls consumption and number  of rolls change will decrease due to rolls wear.

scholarly journals Silicon Steel Strip Profile Control Technology for Six-High Cold Rolling Mill with Small Work Roll Radius

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 401
Author(s):  
Hainan He ◽  
Jian Shao ◽  
Xiaochen Wang ◽  
Quan Yang ◽  
Xiawei Feng
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Steel Strip ◽  
Work Roll ◽  
Rolling Process ◽  
Silicon Steel ◽  
Cold Rolling Mill ◽  
Strip Profile ◽  
Profile Control ◽  
Small Work

Due to the requirement of magnetic properties of silicon steel sheets, producing high-precision size strips is the main aim of the cold rolling industry. The tapered work roll shifting technique of the six-high cold rolling mill is effective in reducing the difference in transverse thickness of the strip edge, but the effective area is limited, especially for a high crown strip after the hot rolling process. The six-high mill with a small work roll size can produce a strip with higher strength and lower thickness under a smaller rolling load. At the same time, the profile of the strip can be substantially improved. By advancing a well-established analytical method, a series of simulation analyses are conducted to reveal the effectiveness of a small work roll radius for the strip profile in the six-high cold rolling process. Through the analysis of flattening deformation and deflection deformation on the load, the change rule of the strip profile produced by the work roll with a small roll diameter can be obtained. Combined with theoretical analysis and industrial experiments, it can be found that the improvement effect of the small work roll radius on the profile of the silicon strip is as significant.

scholarly journals Investigation and Optimization of Load Distribution for Tandem Cold Steel Strip Rolling Process

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 677 ◽  
Author(s):  
Xin Jin ◽  
Changsheng Li ◽  
Yu Wang ◽  
Xiaogang Li ◽  
Yongguang Xiang ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Cold Rolling ◽  
Prediction Model ◽  
Load Distribution ◽  
Rolling Mill ◽  
Fitness Function ◽  
Steel Strip ◽  
Rolling Process ◽  
Cold Rolling Mill ◽  
Tandem Cold Rolling

In order to improve the cold rolled steel strip flatness, the load distribution of the tandem cold rolling process is subject to investigation and optimization. The strip deformation resistance model is corrected by an artificial neural network that is trained with the actual measured data of 4500 strip coils. Based on the model, a flatness prediction model of strip steel is established in a five-stand tandem cold rolling mill, and the precision of the flatness prediction model is verified by rolling experiment data. To analyze the effect of load distribution on flatness, the flatness of stand 4 is calculated to be 7.4 IU, 10.6 IU, and 16.8 IU under three typical load distribution modes. A genetic algorithm based on the excellent flatness is proposed to optimize the load distribution further. In the genetic algorithm, the classification of flatness of stand 4 calculated by the developed flatness prediction model is taken as the fitness function, with the optimal reduction of 28.6%, 34.6%, 27.3%, and 18.6% proposed for stands 1, 2, 3, and 4, respectively. The optimal solution is applied to a 1740 mm tandem cold rolling mill, which reduce the flatness classification from 10.8 IU to 3.2 IU for a 1-mm thick steel strip.

scholarly journals Dataset showing steel cold rolling process parameters for a 6-high cold rolling mill in Nigeria

Data in Brief ◽  
2018 ◽  
Vol 18 ◽  
pp. 891-901
Author(s):  
Emmanuel O. Ayuba ◽  
Christian.A. Bolu ◽  
Temitope M. John ◽  
Abiodun A. Abioye
Keyword(s):  
Cold Rolling ◽  
Process Parameters ◽  
Rolling Mill ◽  
Rolling Process ◽  
Cold Rolling Mill

scholarly journals Usage of Real Time Machine Vision in Rolling Mill

2021 ◽  
Vol 13 (7) ◽  
pp. 3851
Author(s):  
Jiří David ◽  
Pavel Švec ◽  
Vít Pasker ◽  
Romana Garzinová
Keyword(s):  
Rolling Mill ◽  
Optical Character Recognition ◽  
Rolling Process ◽  
Operating Conditions ◽  
Inspection System ◽  
Automatic Identification ◽  
Identification System ◽  
Successful Implementation ◽  
Technical Equipment ◽  
Automatic Inspection

This article deals with the issue of computer vision on a rolling mill. The main goal of this article is to describe the designed and implemented algorithm for the automatic identification of the character string of billets on the rolling mill. The algorithm allows the conversion of image information from the front of the billet, which enters the rolling process, into a string of characters, which is further used to control the technological process. The purpose of this identification is to prevent the input pieces from being confused because different parameters of the rolling process are set for different pieces. In solving this task, it was necessary to design the optimal technical equipment for image capture, choose the appropriate lighting, search for text and recognize individual symbols, and insert them into the control system. The research methodology is based on the empirical-quantitative principle, the basis of which is the analysis of experimentally obtained data (photographs of billet faces) in real operating conditions leading to their interpretation (transformation into the shape of a digital chain). The first part of the article briefly describes the billet identification system from the point of view of technology and hardware resources. The next parts are devoted to the main parts of the algorithm of automatic identification—optical recognition of strings and recognition of individual characters of the chain using artificial intelligence. The method of optical character recognition using artificial neural networks is the basic algorithm of the system of automatic identification of billets and eliminates ambiguities during their further processing. Successful implementation of the automatic inspection system will increase the share of operation automation and lead to ensuring automatic inspection of steel billets according to the production plan. This issue is related to the trend of digitization of individual technological processes in metallurgy and also to the social sustainability of processes, which means the elimination of human errors in the management of the billet rolling process.

Recognition and Control of the Influence Factors on the Surface Defects of Cold Rolled Strip with Emulsion Lubrication

2013 ◽  
Vol 456 ◽  
pp. 498-502
Author(s):  
Yan Li ◽  
Jian Lin Sun
Keyword(s):  
Cold Rolling ◽  
Surface Quality ◽  
Surface Defects ◽  
Surface Condition ◽  
Influence Factors ◽  
Black Spot ◽  
Rolling Process ◽  
Rolled Strip ◽  
Strip Surface ◽  
Cold Rolled

In cold rolling, good surface quality should be maintained with the requirement of constant increasing productivity. Oil-in-water (O/W) emulsions are widely used in cold rolled strips due to their good characteristics as lubricants and coolants. The strip surface defect is one of the central quality problems in the rolling process. A poor strip surface quality after cold rolling may have a large impact on the downstream process, like annealing, galvanization and painting. The surface condition could be deteriorated in many forms affected by various factors. However, few reports focused on the effect of the lubricating property of emulsion on the final surface quality. In this paper, the general surface defects of cold rolled strips such as watermark defects, black spot defects, heat scratches and corrosion defects were analyzed by scan electron microscope (SEM) and energy spectrum analysis (EDS) and the morphology and composition of the defects have been researched. The reason of the surface defects generated is analyzed, and the factors which introduce the surface defects during rolling process are presented. Therefore, it has an important significance to identify the features of the surface defects and put forward the solution measures.

scholarly journals Thin Strip Profile Control Capability of Roll Crossing and Shifting in Cold Rolling Mill

2013 ◽  
Vol 773-774 ◽  
pp. 70-78 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei ◽  
Xiao Dong Wang ◽  
Hasan Tibar
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Rolling Force ◽  
Work Roll ◽  
Rolling Process ◽  
Thin Strip ◽  
Strip Rolling ◽  
Strip Shape ◽  
Strip Profile ◽  
Profile Control

Controlling cold strip profile is a difficult and significant problem has been found in industry during thin strip rolling. At present choosing the new type of strip rolling mill is the one of main methods to control the strip shape quality in cold rolling. The influences of rolling process parameters such as the work roll cross angle and work roll shifting on the strip shape and profile of thin strip are recognised throughout this study. The results show that the roll crossing and shifting is efficient way to control the strip shape. The increase of the work roll crossing angle would lead to improve the strip profile significantly by decreasing the exit strip crown and edge drop. The strip profile would be enhanced if the axial roll shifting was increased. Moreover, the total rolling force was analysed in detail by changing the roll cross angle and axial shifting roll.

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