Jiri george drobny, in handbook of thermoplastic elastomers second edition, 2014. The hot rolling process the primary function of the hot strip mill is to reheat semifinished steel slabs of steel nearly to their melting point, then roll them thinner and longer through 12 successive rolling mill stands driven by motors totaling 77,000 hp, and finally coiling up the lengthened steel sheet for transport to the next process. In section 4, architecture and learning algorithm fuzzy neural networkof have been presented. Modern rolling mills, and specially cold tandem mills with high productivity, are. Fag rolling bearings in rolling mills schaeffler group. In the finishing sections of such lines with rolling speeds of up to 100 ms and higher, rolling is carried out on a single strand. Modern rolling mills, and specially cold tandem mills with high productivity, are equipped with a number of transducers participating in automatic control systems. Analysis of deformations of rolls in the sixhigh tandem mill on the. Pdf the effect of tension variation in the dynamic roll. These skinpass mills in two high design provide high gloss strip surfaces. Pdf life of rolls in a cold rolling mill in a steel plantoperation. Stresses from hertzian pressure in 4high cold mill back up rolls were.
The research for this theme purpose have been made on a 170 mm reversing twohigh rolling mill. The principal design consists of two horizontal rolls, usually of equal size, arranged side by side and rotating toward each other at different speeds. In two high reversing rolling mills the rolls rotate ist in one direction and then in the other, so that rolled metal may pass back and forth through. The work rolls in four high strip mills and the rolls in two high finesection and wire mills are predominantly fitted with angular contact ball bearings as axial bearings figure 10.
Differences are determined for the nature of change. The photo right shows a 2 high rolling mill used for skin passing and reducing soft materials such as lead and copper. Rolling mill element machinery supplies rolling mill. Wo2009041946a1 backing assembly for use in zmill type. Operator controls mill operation of the comprehensively modernized tandem cold mill. Tandem mill two high two stand compaction hot liquid mill metal feed continuous strip casting line 1.
The mill provides forging action as well as rolling action at the same time. In its simplest form, a rolling mill fig 1 consists of two driven rolls in a mill stand with a. A basic understanding of the mechanics of rolling mill rolls file. A four high mill has four rolls, two small and two large. Three high rolling mills consist of a large back up roll, small work roll, and another large back up roll. Rolling mill are classified according to the number and arrangement of roll in a stand. Strip thickness control of cold rolling mill with roll. I published this ebook in march 2003, for free downloads from esw homepage. Find used or surplus rolling mills, 2 hi, fenn, waterburyfarrel, bliss, stanet, danieli directory of 70000 listings by 1200 suppliers. One stand and two frames are made from fabricated steel plates. Pdf characteristics of rolling mills with roll shifting. Consider rolling of a flat plate in a 2high rolling mill. Development of cluster mill simulator for thin strip and foil. What is the advantage of using cluster mill or 2 high.
The rolls may be flat or grooved, and are kept at a fixed distance apart from each other. The evaluation includes roll deflection, pressure of rolls in contact, roll exit thickness distribution, and so. Work rolls manual roll adjustment forced water cooled rolls both rolls driven manual outboard 43 passline 5 x 7 mill housing pushbutton controls 20 hp ac motor removed and in sto. Forced transverse vibration of rolls for four high rolling mill article in journal of central south university of technology 166. The supply focuses on 2high rolling mills, highcapacity 4high reduction rolling mills, and inline skin pass mill stands. Four high stands can be equipped with work rolls of varying. A reversing mill can be used to reduce material to gauge. Stresses from hertzian pressure in 4high cold mill back up rolls were measured years ago, the results were never published, but of high interest also, maybe later.
In metalworking, rolling is a metal forming process in which metal stock is passed through one. The supply focuses on 2 high rolling mills, high capacity 4 high reduction rolling mills, and inline skin pass mill stands. Pdf there are various reasons by which the damage in the cold rolling mill rolls occurs. In the rolling process, permanent deformation is achieved by subjecting the material to high compressive stress by allowing the material to pass through the gap between two rotating cylindrical rolls. Cluster rolling mill it is basically of two types i. A disadvantage of 2 high rolling mills is the fact that the rolls are. Normally, single row cylindrical roller bearings are used in these cases. Axialclearance a asa function ofradialclearance and contactangle. The specification is that the draft is to be equal on each pass. Two high reversing mill work is fed through rolls in one direction. Aug 28, 2018 a series of cold rolling operations are to be used to reduce the thickness of a plate from 50 mm down to 25 mm in a reversing two high mill. To realize high accuracy in the strip exit thickness, the automatic gauge control agc system is used.
For over 60 years, asps rolling mills provided the industry with high production 2high, 4high and cluster mills. The chock arranged on the drive end is not axially located in the roll stand, but is guided on the roll neck by the axial bearing. Companion volume to cold rolling of steel by william roberts circa 1978 and number two of the series. With this small lightweight, hand operated two roll mill you are able to carry your tool to most alternative workspaces when needed. Autoplay when autoplay is enabled, a suggested video. A wide range of sizes with separating force capacities from 10,000 lbs to over 3,000,000 lbs are available. Stresses from hertzian pressure in 4 high cold mill back up rolls were measured years ago, the results were never published, but of high interest also, maybe later. For backup roll bearings of special multistage rolling mills. Because of roll eccentricity in backup rolls, the exit thickness deviates periodically. Additionally, it is possible to conduct the process in two rolled and threerolled system with the application of various guiding devices. These types of mills are commonly used to hot roll wide plates, most cold rolling applications, and to roll foils.
Rolling mill classification rolling mill is used to reduce successively the thickness of the metal strip as per the requirement. Three high mills are commonly used for making bearing material for gasoline and diesel engines see cladding. Thanks to its broad range of cold rolling mills for strip widths from 60 to 2,100 mm. Backup rolls are intended to provide rigid support required by the working rolls to prevent bending under the rolling load. This is a revolutionary new machine that in any other era would have been patented and made the inventor huge profits. The rolling mill is characterized by a large versatility, allowing for the application of various types of working rolls sizing. A z mill or sendzimir mill is a machine for rolling steel.
The high development status of our cold rolling mills is only possible because of. Characteristics of rolling mills with roll shifting. Andritz metals is also seen as the world market leader regarding innovative technologies for 20 high rolling mills. Cold rolling mills yogijidigi can be your preferred supplier for cold rolling mills starting from planning, engineering, implementation and modernization of your plant. Rolling mill animation for 9 stands hot rolling duration.
The number 2 rolls on this cold rolling mill are made of chilled material. Skin passing or temper rolling can be performed in dry or wet operating mode. The mcdonald mill is not just a set of plans but a fantastic invention. Roll diameter 700 mm and coefficient of friction between rolls and work 0. The purpose is to have a very minimum amount of reduction.
Its calculation speed is high, and the prediction results of the strip profile and. Rolling is the process of reducing the thickness or changing the cross section of a long workpiece by compressive forces applied through a set of rolls, as shown in figure 51. The roll mill is the simplest batch mixing equipment. Some basics of rolling and rolling mills rolling is the process of plastically deforming metal by passing it between rolls. Recorder charts showing variations in steel strip thickness on the first stand of a tandem mill, a with manual control and. Fag rolling bearings for rolling mill applications. These rolls may rotate only in one direction no reversing or in two directions reversing. It is the most widely used forming process, which provides high production and close control of final product. It is used for rolling thick work piece in single pass.
These stands are arranged so they can roll the work piece in decreasing cross section. A cluster mill has more than 4 rolls, usually in three tiers. There will be two high mill at the beginning feeding the work piece to the planetary mill. The 2hi cold rolling mill is a kind of portable type. Hot rolling mills are used for mass thickness reduction at high temperatures, whereas the cold rolling mills are used as secondary rolling operations to attain more precise dimensional and mechanical properties. The material is to be passed in between these two rolling mills such that the compressive forces can changes its thickness from the original. Rolling is the process of reducing the thickness or changing the cross section. Development of cluster mill simulator for thin strip and. All rolling mills have common construction that is independent of the specific type of rolling required. With more than 50 references for skin pass and temper mills in 2 high or 4 high design inline or offline, sundwig is one of the most notable suppliers in this rolling mill technology segment. This machine is developed to be used on a workbench.
Pctus2007020890 backing assembly for use in zmill type rolling. Analysis is done on two types of roles that is 4 hi and 20 hi. Leonardo da vinci invented the first rolling mills but only after a few centuries rolling mills became important for the steel industry. At the out let end there will be another set of two high mill to take the out coming work. Feb, 2015 three high rolling mill three high rolling machine three high rolling stand. Rolls deformation and roll force distribution between rolls on a sixhigh mill are calculated by influence. A four high rolling mill is used for the hot rolling of armor and other plates as well as cold rolling of plates, sheets and strips. Due to different numbers of rollers, the metal coil cold rolling mill is divided into 2 hi, 4 hi, 6 hi, and 12 hi agc. In rolling mill, the accuracy and quality of the strip exit hickness aret very important factors. Rolling mills metal processing machinery american steel. Two high generally used for hot or cold breakdown and finishing of bar, sheet or strip. Unlike a traditional rolling mill this 20 high cluster mill configuration utilizes cascaded supporting rolls to apply force on the small work rolls in the center. The strip shape standard curve in a tandem cold rolling mill was. A 3 high rolling mill consists of three rolls and is typically used for either performing multiple reduction passes by wrapping material around the center mill roll, or for bonding of dissimilar stacked material passed through the mill.
The reversing mill is so named because the steel runs back and forth between the rollers, reducing the thickness incrementally with each pass. Metal forming is the main method of making metal products and semifinished products. Cold rolling mill for aluminium sheet high impact factor. Sixhigh tandem mills are widely used in the manufacturing and processing. For one revolution of the top roll the resultant rolling load p moves along the circumference of a circle equal to 2a since there are two work rolls involved, the work done is equal to work done 2 2 a.
Three high a desirable type of mill for rod and ingot breakdown when an economic solution is essential. The stiffness of the housing, the rolls, and the roll bearings are all important in controlling and maintaining the thickness of the rolled strip. Pdf download for analysis of deformations of rolls in the sixhigh. Nov 14, 2018 the explanation of the above metal rolling types was as follows. The rolling mill is equipped with strain gauge measurement system registering. Jul 12, 1983 a two high rolling stand for use in a plurality of stands constituting a rolling mill comprising a roll package having a pair of rolls with axial directions arranged in parallel, said roll package including bearing devices and housing therefor operable to support said rolls within said stand, end members arranged to exert force on said roll. A two high rolling mill can further be classified as a reversing and a nonreversing mill. Tandem rolling is also known as continuous rolling in which two or more set of four high rolling mill arranged in a series in which each set is called stand. In this paper, we design pi controller in outer loop. Impact analysis of roller system stability for fourhigh mill.
More than 90% of smelted metal is processed by different methods of metal forming. Rolling bearings generally consist of bearing rings inner ring and outer ring, rolling elements which roll on the raceways of the rings, and a cage which surrounds the rolling elements. Forced transverse vibration of rolls for fourhigh rolling. The term high tech rolling includes all cold rolling technologies where there is a good balance between the technical and economic advantages. But that disadvantage of rolls are heed to stopped, reversed and become back up to rolling speed between each pass. Some basics of rolling and rolling mills ispatguru. Use is also made of four high stands for ferritic stainless steels. A tandem mill is one in which the metal is rolled in successive stands. The evaluation includes roll deflection, pressure of rolls in contact, roll exit thickness distribution, and so on. Nov 09, 2016 the material is subjected to high compressive stresses from the squeezing action of the rolls and to surface shear stresses as a result of the friction between the rolls and the metal. A 2 high mill can make a slight reduction and lay the material out flat and uniform.
A 300mmwide strip 25mm thick is fed through a rolling mill with two powered rolls each of radius 250 mm. The production hall for the rolling mill was assumed to cover an area of 73. Twohigh rolling stand for bar andor wire rolling mill. Modern four high mills all set corresponding offset value 1, 2, such as 2050 cvc four high rolling mill and 4300medium plate mill of the german sms, fourroll rolling mill of the british davy, 1580pair cross four high rolling mill of japan mitsubishi heavy industries. Number ten of the manufacturing engineering and material processing series. In section 3, a mathematical model has been driven for singlestand cold rolling mill. Thorough account of the hot rolling process and facilities as well as followup treatments given to hotrolled products. Research and development trend of shape control for cold rolling. Test rolling is performed for austenitic steel 12kh18n10t workpieces in two high and three high screw rolling mills. The sundwig 4 column design, which andritz sundwig was the first to offer, has many important. The final chapter explains the purpose of roll pass design to ensure the maximum output at minimum cost as well as to reduce the roll wear to a minimum. Harder hcrs will cause muscle power to fail after very short. United states patento rolling mill spindle and coupling application june 11, 1951, serial no. Two high reversing mill direction of rolls spin is reversed and the work is fed from the opposite direction.
Ifradialcylindricalroller bearings are used, the thrustloadshave to be accommodated bya separate bearing. A disadvantage of 2 high rolling mills is the fact that the rolls are large in diameter giving you limited reduction. A reversing mill is a rolling mill in which the workpiece is passed forward and backward through a pair of rolls. We are a leading distributor of mill rolls to the north american steel mill industry, with significant share of the long bar market.
Chock wall thickness sectional height roll body dia. It consists of two rolling mills which are rotated in opposite directions to each other. A rolling simulator for the cluster mill, especially the 6hi x and 10hi x type mills besides the conventional 4 high mill, has been developed for evaluation of rolling thin strips and foils. This book discusses as well the different types of rolls for various rolling mills, including blooming, plate, sheet, sheet bar, small section, heavy product, skin passing, and cold rolling mills. Two high, four high and six high stands socalled two high bright mills are employed for treating austenitic stainless steel strip. Forming processes are those in which the shape of a. Two roll mills for milling and calendering 2 part silicone like versasil product range. Plastic properties of metals are used during the process of metal forming. This allows the application of a higher roll pressure without bending the work rolls, which would result in poor metal quality. The premature failure of a cold mill roll increases not only the cost of the rolls but also the down. This paper investigates the nature of chatter, which is related to vibrations in horizontal and vertical direction, introducing the bearing dynamics and tension variation models, identifying transient characteristics of the coupled mass elements and. The material is subjected to high compressive stresses from the squeezing action of the rolls and to surface shear stresses as a result of the friction between the rolls and the metal. Peterson rolling mill spindle and coupling 4 sheetssheet 14 filed june 11, 1951 rh. What is the advantage of using cluster mill or 2 high rolling mill answer purdue university ie 370 fall 2015.
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