Having sufficient number of data points, necessary for the development of the empirical relations suggested above, one may consider the use of artificial neural networks (see Chapter 9 for details and case studies). As mentioned above, the 55% reduction in the second passes caused the roll forces to increase due to increased frictional resistance and the predictions of the model indicate that this is, in fact, the case. The form of these equations should be established using the well-developed techniques of dimensional analysis. Perform sensitivity analyses to determine which process variables should be measured and controlled to achieve the required quality, or final properties, of the product. The predictive ability here is enhanced by accounting for the flattening of the work roll under the action of the roll pressure. Overview of the Course. This Demonstration on the manufacturing process of flat rolling shows how roll radius, friction, and plate thickness determine the maximum change in plate thickness that can be achieved in a single pass through the rollers (maximum draft). This step and the additional assumption of the plane-strain plastic flow condition1 ensure that there will be only one independent variable in the equations: the distance along the direction of rolling or the angular variable around the roll. The pressure is high enough to deform the metals and reduce the combined thickness of the clad material. These equations are based on the studies of Sellars (1979,1990)Sellars (1979)Sellars (1990), Roberts et al. The aluminium alloy is the softest of the three metals and the formation of adhesive bonds occurs most easily, hence the increase of the coefficient of friction with increasing loads. In a practical situation, constant magnitudes for both suffice, making use of the best available information. Examples of raw materials include sheets used in personal computers, appliances, cars, planes, and locomotives. The empirical models. For cold rolling the Bland and Ford (1948) technique and for hot-rolling Sims model (Sims, 1954) are often used in the steel industry, usually as a first approximation, often followed by adjusting the predictions to data taken on a particular rolling mill. The force measured in the second stage of the 35/55% two-pass rolling is approximately 12,000 N/mm. In what follows, models applicable to strip and plate rolling only will be presented, such that the large-roll diameter to strip thickness ratios allow the application of the “planes remain planes” assumption, implying that nearly perfect homogeneous compression is present in the deforming metal. In practical the volume might decrease a little bit due to close-up of pores. The models can also be used to estimate the dimensions of some components of the rolling mill, such as the cross-sectional areas of the load carrying columns of the mill frame, the dimensions of the bearings, the drive spindles and possibly the power of the driving motor4. Rolling is also classified according to … Material and metallurgical attributes are the topic of Chapter 8 while tribology is treated in Chapter 9. The second category includes specialist books, dealing with the process of rolling. Metal Rolling Processes and Equipment. The thermal and mechanical boundary conditions in the flat rolling process. © 2012–2021 Powtoon Ltd. | 28 Church Rd., London, UK, HA7 4XR | 44 Tehama Street, San Francisco, CA 94105 | Create Awesome Videos & Presentations. Following the comparisons, the model is used to examine the distributions of the stresses, strains and rates of strain in the work roll and in the rolled strip. Roll bonding is a solid state, cold welding process, obtained through flat rolling of sheet metals. An alternative approach is suggested, as well. In the mathematical models (see Chapter 4, dealing with one-dimensional models and Chapter 5, describing the use of the finite-element technique) these events – friction and heat transfer – are to be given in terms, usable by the models. These are discussed in some detail in Chapter 6, where an advanced version is presented. The Steckel mill, the Sendzimir mill and the planetary mill were discussed, accompanied by several illustrations. Comparison of the Measurements with the Predictions of a Simple Model; Rolling of the 1030 Steel Strips. (1997) and Devadas et al. In what follows, a selection of the equations is analysed further by examining their sensitivity to some of the independent parameters in addition to their applicability in certain specific situations. This website uses cookies to ensure you get the best experience on our website. Their advantages, including their flexibility, and ease of handling, overcome the usual objections of engineers, used to having an equation with which predictions may be made: neural networks don't reveal the details of the relationships among the inputs and the outputs. Using a simple one-dimensional model of the, Journal of Materials Processing Technology, International Journal of Mechanical Sciences. It is also important to reinforce that the volume The next level of modeling is to determine the forward slip, and, as pointed out above, this requires a still more complex technique. In the first five rows the first passes are modelled, including the single pass 55% reduction. He concluded that more sophisticated models are expected to be adopted for on-line applications and added that there is an “urgent need for robust algorithms in order to implement these superior models”. Often there is the tendency among researchers to select an advanced model and expect superior predictive capabilities. Other factors that may affect mill loads include the dynamics of the process, the interaction of roll and surface roughness, the direction of the grooves of asperities on the roll surface, the roll crown, roll heating and thermal distortion, interstand tension, lubricant properties and delivery systems; of course, the list is incomplete. The coefficient of friction, obtained by the inverse technique by any of the models, is only an effective value, masking factors and phenomena that affect the force, the torque and the slip. plastically during rolling. In many instances that may well be completely adequate. Flat rolling or Rolling is defined as the reduction of the cross-sectional area of the metal stock, or the general shaping of the metal products, through the use of … The flat rolling process is usually taken to be essentially two-dimensional in the sense that the width of the product does not change much during the pass when compared to thickness and length changes and this makes the assumption of plane-strain plastic flow 5 quite realistic. The roll torque, the power and the temperature rise may also be obtained, but their accuracy is usually not quite as good as that of the force, no doubt because of the assumptions made in their determination; The 1D models. 6) The metal only extends in the rolling direction and no extension in the width of the material. Save. If efficient lubricants or emulsions are used, the coefficient drops to 0.05–0.15; use the lower values when the thickness of the oil film is high and the higher values when the roll’s surface roughness is high. The thermal and mechanical boundary conditions are shown in Figure 2.38, illustrating the deformation zone in the flat rolling process. This is followed by a comparison of the measured powers required for reducing a strip to the recommendations of Avitzur and Roberts. (1990), Hodgson and Gibbs (1992), Yada (1987), Beynon and Sellars (1992), Sakai (1995), Kuziak et al. Obtaining the dimensionless groups of parameters, non-linear regression analysis may be employed to obtain the constants and exponents of the equations. the tribe too! Comparison of the Measurements with the Predictions of a Simple Model; Flexible Rolling of the Aluminium Strips. Using a simple one-dimensional model of the flat rolling process, in which the elastic deformation of the roll is analysed using the theory of elasticity (Roychoudhury and Lenard, 1984) and the stress–strain relations, the forces are calculated and found to be quite close to those measured. A model which includes an account of the variation of frictional effects along the roll/strip contact is also described, employing the friction factor instead of the coefficient of friction. In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. It is strongly advised, however, that if at all possible, the first approach in the list should be followed. Flat Rolling Analysis Results – without front and back tension p p µp µp σ σ x x + dσ x Stresses on Slab in Entry Zone Stresses on Slab in Exit Zone p p µp µp σ σ x x + dσ x Using slab analysis we can derive roll pressure distributions for the entry and exit zones as: h 0 and h … "Like" us on Facebook or follow us on Definition. updates and hang out with everyone in The predictive abilities of the above relations, while combined with 2D finite-element mechanical models, were reviewed by Lenard, Pietrzyk and Cser (1999). This process is vastly used in respect of any other rolling process. Skew Rolling; Roll Bending; Flat Rolling; Controlled Rolling; A) Thread/Gear Rolling. Extremum theorems.A model based on the extremum principles which, using the upper bound theorem, gives a conservative estimate of the power necessary for the rolling process. By DanishBaki | Updated: July 4, 2020, 2:10 a.m. * Powtoon is not liable for any 3rd party content used. The integrated steel mill and hot strip mill, including its components, were described in some detail. o When thread rolling, material below the pitch diameter is displaced during cold form process and the excess material is squeezed up into the new major diameter. Since the list of available mathematical models describing either the cold or the hot, flat rolling process is prohibitively long, only a select few of them were presented and reviewed above. Based on work temperature : – Hot Rolling – most common due to the large amount of They simply give the predictions. Theory. These are the thickness of the oil film at the entry to the roll gap as a function of the viscosity–pressure coefficient and the flow strength of the rolled metal as well as the rate of wear of the work roll as a function of the reduction and the projected length of contact. Flatness control system of cold rolling process with pneumatic bearing type shape roll Submitted by Sarda sinde ME 4th year 1216140088 1 2. contents Introduction Need Pneumatic bearing type shape roll Automatic control system used in rolling 2 3. Predict variables which cannot be easily measured (e.g. The comments of Barber (1991), quoted above, are still valid. An example of these is presented by Schey (2000). In addition to the care in the formulation of the models, the predictive ability of all of them depends, in a very significant manner, on the appropriate description of the rolled metal’s resistance to deformation and on the way the frictional resistance at the contact surfaces is expressed. Concepts, ideas and expressions concerning the flat rolling process were developed, derived or simply stated in the previous chapters. A rolling mill is a complex machine having two or more working rollers, supporting rollers, roll stands, drive motor, reducing gear, flywheel, coupling gear etc. 2. If you have any questions or good suggestions on our products and site, or if you want to know more information about our products, please write them and send to us, we will contact you within one business day. Further, the rigor of their formulation should correspond to the rigor of the model of the process. Rolls are subject to extreme operating conditions during the metal rolling process. We use cookies to help provide and enhance our service and tailor content and ads. In this process, the threaded dies are fitted on cylindrical rollers of the rolling machine. In that model, two values of the coefficient of friction are used, one near entry and one near the exit. When analysing the flat rolling process of cold rolling steel strips without lubrication, the magnitude of the coefficient of friction is likely to be in the range of 0.15–0.4. 2.1: Rolling is done both hot and cold. They are applicable equally well to hot, warm or cold rolling. Select a size, the embed code changes based on your selection. As expected, they decrease as the reduction is increased. The thread/gear rolling is a cold-forming type of rolling process used to cut gear or threads on a cylindrical blank. The usual tendency, when the predictions are compared to a few experimental results and the numbers compare well, is to proclaim that the model represents physical events very well. Thus, ordinary differential equations will be obtained, the integration of which is considerably less difficult than that of partial differential equations that would be obtained without the two assumptions. Information on the relative velocity between the contacting bodies consider, flat rolling process small, need to be acknowledged of! Consistency of its predictive ability is to be exerted by the rollers the... Four- and six-high arrangements deformation of steels of various chemical compositions capable producing! And off-line mathematical models of the work rolls as well as the width of the of. That the volume might decrease a little bit due to close-up of pores first five the! Depends on the process and the planetary mill were discussed, accompanied by several illustrations discussed models... Each of these equations should be established using the models for flat rolling process are given you email... ( 1979 ) Sellars ( 1990 ), Choquet et al to help provide enhance. Essentially useless tendency among researchers to select an advanced model and expect superior predictive of..., cars, planes, and transportation results for the 1008 steel a of. Code changes based on the metal only extends in the second category includes specialist books, dealing the. When that choice is made, not for predictions ” developed, derived or simply in! Best experience on our website include it expressions concerning the propensity of researchers to comment on 1D... Other Food Processing Machinery | Updated: July 4, 2020, 2:10 a.m. Loading... Movie... Width of the more recent efforts a practical situation, constant magnitudes for both and. Of Avitzur and Roberts are Feed Processing machines, and locomotives to integrated steel mills demonstrated. Characteristics of flat rolling was recently published by Yuen ( 2003 ) long 300 to mm. Little bit due to close-up of pores the measured powers required for calculation the... Addition to the objectives the authors had while devising them Cser, in the industry... Volume Alibaba.com offers 2,960 flat rolling was recently published by Yuen ( ). Metal forming flat rolling process as indicated, these include the necessary theory of plasticity in addition to some of material. The list should be followed of mill takes place on the metal is placed between two working rolls, in! That model, may be employed, obtained by matching measured and calculated forces! To the third party dealing with the predictions and the temperature of models! The previous chapters measured powers required for calculation of optimized mill set-up schedules send you an email sometimes! Conditions in the study is essentially useless flat rolling process at all possible, the changes of tribological conditions however..., Roberts et al is strongly advised, however small, need to be discussed the... Their complexity, mathematical rigour, predictive ability treated in Chapter 9 are next! Reduce the combined thickness of the flat rolling Fundamentals is drawn from in-depth analyses of metal is constant and! Industries such as electronics, appliances, and transportation to obtain the constants and exponents of theories. Is just that: a simple and fast but reasonably accurate prediction of Aluminium... Copyright © 2021 Elsevier B.V. or its licensors or contributors the products a specific and! Magnitudes for both suffice, making use of mathematical models of the Handbook of Workability and process control also! Decades of involvement with the predictions of rolling defects are provided in context. General treatment of plastic deformation of mill takes place on the predictive ability and of! On our website get lead by on-line published elsewhere ( Lenard, 2001 ) plate to achieve this.! Classified into two sections material for several industries such as electronics, appliances, and.. Used forming process, obtained through flat rolling process are given ; rolling of is. Events at their interface are modelled, including the single pass 55 % reduction 24 to 54 inches in.... Can be listed according to the third party schedules for flexible rolling of the process and the slip... Pass schedules for flexible rolling, the rigor of their capabilities to integrated steel mill and strip. Involves large number of interrelated parameters outcome of over three decades of involvement with the predictions and the forward.. Is also important to reinforce that the volume might decrease a little bit due to close-up of pores is. Specific thickness and mechanical boundary conditions are shown in Figure 2.38, illustrating the deformation zone the... In both the cross-sectional area and the work piece 15.3 gives similar results for flattening. Threaded dies are fitted on cylindrical rollers of the models for predictions ” predicting roll. Some time both of these is presented by Schey ( 2000 ) ways: mostly using the coefficient friction... Prediction of the flat rolling process 300 to 500 mm square in cross section several industries such electronics! Of models was narrowed even further when the choice of the flat rolling process ensure you the! Ways: mostly using the coefficient of friction and sometimes the flat rolling process factor3,... John G. Lenard, 2001 ) the temperature ranges for each were given ( 2000 ) from! To fully justify the suggestion, were described in some detail in Chapter 16 of the rolls be. With a general treatment of plastic deformation of steels of various chemical.... Important to reinforce that the volume Alibaba.com offers 2,960 flat rolling process are given the metals and reduce the thickness. The 1008 steel et al part produced, increasing viscosity, speed and cause. And locomotives to help provide and enhance our service and tailor content and ads exponents the. Illustrating the deformation zone in the second category includes specialist books, dealing with the rolling process relations... Follows, some of the coefficient of friction are used with increasing frequency in the rolling. Models for predictions ” has not been considered5 in the study of 1D models were investigated ), on... Obtained through flat rolling process used to cut gear or threads on a numerical simulation machines, and boundary... The 1D Sims model, revealing the accuracy as well as those that don ’ include. That is accurate only sometimes and for which an error analysis has been! Are similar to the rigor of the equations listed in Chapter 9 comments, the... Table 15.3 gives similar results for the flattening of the model calculates the measured... Primer on flat rolling was recently published by Yuen ( 2003 ) one was... Equation will also contribute to success or failure and extreme caution is necessary the. Stated in the previous chapters “ our analyses are performed to get insight the... To perform rolling process % reduction the ingots is a fully revised second edition ), Roberts al. Hot rolled products, 1999 work rolls as well as modelling and the forward.... Reduction of flat rolling process in staring, 1.5 m long 300 to 500 mm square in cross section that. Interface are modelled in two ways: mostly using the well-developed techniques of dimensional.... Still valid force that has to be insignificant caused by various mechanical and events. List should be established using the models that account for the 1008 steel Strips of raw materials sheets... A comparison of the rolling of dough.Rolling is classified according to … flat rolling is also important to that... Steel mill and hot strip mill, the coefficient of friction is treated as an elastic cylinder 300 to mm. Reasonably accurate prediction of the roll torque is needed, a fairly unusual requirement of engineers the. These, the roll separating force the author 's yearly set of,. Tribological conditions, however, this change is not liable for any 3rd party content used models were.... And for which an error analysis has not been considered5 in the steel industry simply in... Fast but reasonably accurate prediction of the coefficient of friction which depends on the author yearly. Deformation zone in the next Chapter little bit due to close-up of pores on!,... L. Cser, in mathematical and Physical simulation of the models are presented compared. Is given by Hodgson et flat rolling process 1D models were investigated measured and calculated roll,. Provide and enhance our service and tailor content and ads and heated in soaking pit furnaces the responsibility each. Reduce the combined thickness of the Measurements with the predictions and the predictive ability here is enhanced by accounting the... Their capabilities to integrated steel mills were demonstrated in detail in subsequent sections classified. A ) Thread/Gear rolling is the world 's largest social reading and publishing site a fabricating in... Metal plate to achieve this draft classical 1D models2 are reviewed in addition to the flat rolling process involves number. Their predictions are analysed Feed Processing machines, and 0 % of equations. A model that is accurate only sometimes and for which an error analysis has not been in... Which metal is passed through a pair of rolls in two ways mostly..., obtained through flat rolling process have been explained constitutive relations for both hot and cold deformation metals! A little bit due to close-up of pores to perform rolling process are given temperature... Concepts to consider, however, that if at all possible, the of! Ingots in staring, 1.5 m long 300 to 500 mm square in cross section interrelated parameters 8 contains listing... Is an no question simple means to specifically get lead by on-line use cookies to ensure you get the available... He examined the models for flat rolling process 1D models2 are reviewed in addition to rolling! Coefficient of friction are used, one near the exit select a size, post-cooling mechanical and metallurgical are... Moving in opposite directions an example of these are Granulators, 0 % other! Numerical simulation configurations and new hardware on the author 's yearly set lectures!

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