US3858423A

US3858423A - Anvil rollbed cyclic mill and method of rolling

Info

Publication number: US3858423A
Application number: US315099A
Authority: US
Inventors: Tadeusz Sendzimir
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-14
Filing date: 1972-12-14
Publication date: 1975-01-07
Anticipated expiration: 1992-01-07
Also published as: DE2439410A1

Abstract

A cyclic rolling mill is disclosed wherein one or more back-up work rolls of small diameter concurrently traverse, and gradually approach, an anvil. The anvil comprises a plurality of rounded crests parallel to the axis of the workrolls and separated by valleys. The crests and valleys may be in the form of corrugations in a solid block, or they may be provided by a plurality of small diameter anvil rolls; and in the latter case individual adjustment thereof may be provided. A small amount of movement of the anvil, in the direction of strip travel, may be provided, with means to return the anvil to its starting position between working cycles. The work roll and its backing elements may be rocker mounted, and oscillated in a working and return stroke, in which case means are provided to remove the working roll from contact with the workpiece during its return stroke. A number of workrolls may also be mounted in cages about a backing roll.

Description

[19] 1] 3,858,23 Sendzimir Jan. 7, 1975 ANVIL ROLLBED CYCLIC MILL AND [57] ABSTRACT METHOD OF ROLLING A cyclic rolling mill is disclosed wherein one or more [76] inventor: Tadeusz Sendzimir, PO. Box 1350, back-up work rolls of small diameter concurrently tra- Waterbury, Conn. 06720 verse, and gradually approach, an anvil. The anvil comprises a plurality of rounded crests parallel to the [22] 1972 axis of the workrolls and separated by valleys. The [21] Appl. No.: 315,099 crests and valleys may be in the form of corrugations in a solid block, or they may be provided by a plurality of small diameter anvil rolls; and in the latter case in- 72/is8z9ib7igllgg dividual adjustment thereof may be provided. A small [58] Fieid 191 192 amount of movement of the anvil, in the direction of strip travel, may be provided, with means to return the [56] References Cited anvil to its starting position between working cycles.

The work roll and its backing'elements may be rocker UNITED STATES PATENTS mounted, and oscillated in a working and return 873,997 l2/l907 Ebinghaus et al. 72/192 stroke, in which case means are provided to remove g g fthe working roll from contact with the workpiece dur- 1 l in 'ts return stroke. A number of workrolls ma also 3,143,009 8/1964 Pfeiffer 72/191 g 1 y 3,167,980 2/1965 Scribner ..72/1s9 be mounted' cagesaboutaback'ngron' 3,301,032 l/l967 Hirose ..72/ 191 30 Claims, 10 Drawing Figures Primary Examiner-Lowell A. Larson Attorney, Agent, or Firm-Melville, Strasser, Foster & Hoffman v 7 I l 5 Sheets-Sheet 2 Has.

BRIEF SUMMARY OF THE INVENTION In the operation of a rolling instrumentality wherein a non-driven workroll is caused concurrently to traverse and gradually approach a stationary anvil while the workpiece is fed into the instrumentality by means engaging the non-reduced portion of the workpiece, as disclosed for example in Sendzimir US. Pat. No. 3,625,042, the penetration of plastic deformation caused by the workroll is initially limited to a relatively shallow depth in the workpiece; and only after a total elongation of two to three times the original length has been reached, does the structure of the metal workpiece change into a cold worked structure. By way of example, a A. inch by inch continuously cast brass slab, when reduced to one-half of its original thickness, still shows an as-cast structure in the area contacted by the anvil. Since elongation is produced in the area contacted by the anvil by stretching rather than by rolling, and since many metals do not have enough ductility to withstand deformation of this type without discontinuities or cracks, this has proved to be a serious drawback in the use of such mills.

Accordingly, it is an object of the present invention to provide a rolling instrumentality of the cyclic type wherein the anvil is constituted by a plurality of curved or rounded crests parallel to the axes of the workrolls and separated by valleys. With this construction, the workroll only deforms the workpiece when it crosses one of the successive crests; but each time it crosses such a crest reduction is being produced not only by the workroll but also by the crest. Thus, the workhardening of the workpiece is caused to progress both from the top and bottom faces of the workpiece whereby the material is protected from the danger of cracks and the as-cast structure is completely replaced by a work-hardened structure even before the midpoint of a working pass.

A further object of the invention is to provide a mill wherein the slab is held securely even at the tail end of the slab so that the mill becomes self-feeding and it is no longer necessary to'push the tail end of the slab through the mill with a succeeding slab.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a diagrammatic cross section of a rollbite according to the prior art.

FIG. 2 is a view similar to FIG. 1 showing the basic principles of the present invention.

FIG. 3 is a somewhat diagrammatic cross sectional view through another embodiment ofthe invention.

FIG. 4 is a diagrammatic view in plan of the backing structure for the anvil rolls of FIG. 3.

FIG. 5 is a fragmentary diagrammatic view partly in cross section showing the arrangement of the backing elements of FIGS. 3 and 4.

FIG. 6 is a diagrammatic cross sectional view of another embodiment of the invention involving a deflection of the workpiece.

FIG. 7 is a diagrammatic cross sectional view of still another embodiment of the invention.

FIG. 8 is a diagrammatic cross sectional view of details of the mounting of the anvil elements of FIG. 7.

FIG. 9 is a cross sectional view of the structure shown in FIG. 8.

FIG. 10 is an enlarged fragmentary cross sectional view of another detail in the structure of FIG. 7.

DETAILED DESCRIPTION FIG. 1 shows the rollbite ofa conventional single-roll Rocker Mill such as shown in US. Pat. No. 3,625,042. A work-piece 1 is fed into the rollbite by extraneous means, such as feed rolls engaging the unreduced portion thereof. Workroll 2 reciprocates between position 2' at the top and 2" at the bottom of the rollbite and engages the workpiece 1, pressing it against the flat anvil 3 while taking a reduction of 10 percent more or less, depending on the material, all along said rollbite.

Only the area 1' of the workpiece has changed its grain structure to a cold-rolled structure, whereas the remaining area 1 remains in the: original cast or annealed grain structure. At position 2 of the workroll, still more than half of the thickness of the workpiece shows the unreduced grain structure.

FIG. 2 shows the simplest embodiment of the invention where the anvil 3 is provided with a corrugated surface providing rounded crests 3 alternating with valleys 3 running parallel to the workroll 2.

As the workroll 2 travels down the rollbite it deforms the workpiece only at points where it crosses the successive crests 3, but reduction is produced by both tools: the roll Zfrom the top, and the crest 3' at the bottom. Reductions as can be seen are opposite each crest only; but since the workpiece is fed forward by the feedrolls the non-reduced intermediate portions are progressively fed across the successive crests 3', thus producing a complete reduction of thickness of the workpiece 1 to strip la.

At the same time the plastic deformation of the workpiece progresses both from the top and the bottom faces and this protects the material of the workpiece from the danger of cracks.

As workroll 2 passes across each consecutive crest and produces a plastic deformation in the workpiece while so doing, there is a slight relative motion between the workpiece and the crest due to the elongation of the workpiece, and that is not objectionable in most instances. However, since some materials are sensitive to scratching, that relative movement has been reduced by providing a rigid base under the anvil, with a friction-reducing bearing surface at their interface, for least resistance to the forward movement of the anvil, by a distance approximately equal to the elongation of the workpiece during each complete operating stroke of the workroll. Since it is vital that the anvil return to its original position before the workroll commences its next cycle, there has been provided an abutment to limit the backward travel of the anvil, and elastic means such as springs or air cylinders to push it back against said abutment as soon as the workroll has left contact with it. These means may be as shown in FIG. 10 in connection with another embodiment.

It should be noted that the terms crests and valleys are intended to include not only the corrugatedsurface described above, but also a plurality of small diameter anvil rolls which perform the same functions as the crests and valleys of the corrugated surface.

FIGS. 3, 4 and 5 show another embodiment of the invention, in which the anvil consists of a plurality of anvil rolls 3. Each roll is supported by two rows of backing casters 4, mounted on eccentric shafts 5, and backed by supports 6 provided in spaces between each two casters. The supports 6 rest against the rigid stationary beam 7 of the mill housing.

The anvil rolls 3 occupy more space along the rollbite than the crests of FIG. 2, so that for the same number of reductions, a long rollbite is necessary. This is achieved by a workroll reciprocating apparatus consisting of caster backing elements 4 like those provided for the anvil rolls, with the whole assembly mounted on a rocker body 8 whose opposite face is arcuate and is urged by means (not shown) against the rigid upper beam 7 of the mill housing.

Reciprocating means (not shown) are applied to said apparatus and cause the workroll 2 to describe an elongated hypo-cycloidal path from position 2 to 2", while taking reductions of the workpiece 1 as it traverses each successive anvil roll 3.

In order to adjust the position of each anvil roll 3 to take the required pass reductions, screwdown means are provided, consisting of eccentrics 9 keyed onto shafts and located inside the bores of the support 6. Individually motorized worm-gear drives mounted at the end of each shaft 5 to control its angular position, and thereby determine the position of the anvil roll 3 it supports.

The above arrangement makes it possible to apply drive means to some or all of the anvil rolls 3 and thus to permit feeding the trailing end of each workpiece, and for other purposes as described below. Each roll may be driven individually; but the drive may be simplified by applying drive means to one anvil roll, e.g. through splines 12 and mounting a keyed pinion 13, preferably on the other neck of the same roll.

The pinion 13 is in mesh with an idler pinion 13 mounted on the eccentric shaft 5 and attached to a cooperating pinion 14 which is in mesh with a pinion l4 keyed onto the next anvil roll 3, and so on through all or, shown in FIG. 4, one group of anvil rolls.

The above described arrangement makes it possible to obtain gear ratios to achieve angular velocities of successive anvil rolls 3 proportionate to the surface velocity of the bottom face of the workpiece of each anvil roll during actual reduction. The velocity of the roll surface should preferably be in excess of the velocity of the workpiece.

Bearings 15 attached to the beam 7 through tie-rods l6 serve to urge the anvil rolls 3 against their backing casters 4 when transmitting the drive torque.

The embodiment shown in FIG. 6 consists ofa different instrumentality for propelling the workrolls 2 through the rollbite, and is particularly suitable for hot reduction. It consists of a driven backing roll 17 surrounded by, and in contact with, a plurality of workrolls 2, whose necks are carried by chocks located in cages 18 substantially as described in U.S. Pat. No. 3,522,720.

Converging upon the orbit of the workrolls 2 is a quadrant of anvil rolls 3, backed, driven and positioned as described above in conjunction with FIGS. 3, 4 and 5.

The feedrolls 19, 19' advance the red hot workpiece 1 into the thus formed arcuate rollbite, so that the workpiece is bent upwards while being reduced to emerge as strip la.

The strip la is gripped by planishing rolls 20, 20' and propelled upwards, suitably guided, through a fluidized 11 are granule cooling bed 21 and out through exit rolls 22, 22'. Non-oxidizing gas blown through the

openings

23, 23 keeps the granule cooling bed fluid. The granules escape from the bed 21 on top to both sides of the chamber 24 behind the separators 25, 25', and descend through the cooling compartments 26, 26', where cooling is effected, e.g. by submerged

pipes

27 and 27 through which cold water is circulated. Thus the strip la emerges from exit rolls 22, 22' oxide-free and below oxidizing temperature.

Part of the non-oxidizing gas of course travels back along workpiece 1 and protects it against oxidation also during the short period of hot-reduction.

The hot strip mill represented on FIG. 7 differs from that of FIG. 6 in that it is capable of carrying the plastic reduction to much lighter gauges. This is achieved by dividing the anvil roller bed into three parts: first the roughing anvil rolls 3 substantially as provided in the mill of FIG. 6. Secondly, a group of finishing rolls 3a which areshown in more detail in FIGS. 8 and 9. Since these rolls turn only by a very small angle at each pass of a workroll 2, they are made in the form of oscillating dies and are supported along their whole face by the hardened steel block 31, and are held in their initial position by powerful flat springs 32 riveted in slots provided at each end.

The other ends of the springs 32 fit tightly in similar slots provided in the block 31, with the exception that there is a slight chamfer in the channels around the spot where the roll rests on the block, in order to assure that the spring may have an acceptable degree of curvature on deflection.

Bars 33 attached to the block 31 hold the rolls 3a in their axial position.

It will be understood that during each passage of a workroll 2, the elongated workpiece will drag each roll 30 forward by a small distance, against the resistace of the two springs 32, which will bring the roll back to its original position as soon as the workpiece is relieved of the roll pressure.

As the thickness of a workpiece diminishes during its passage through the rollbite, some'materials, especially some refractory metals, show a considerable work hardening. This increases the roll separating force and produces more roll flattening, The present process substantially reduces that difficulty, in that the radii of successive rolls and/or roll segments can be made smaller, whereby the roll separating force is diminished in spite of the fact that the cycling roll diameter remains constant.

In this way, the finishing passes are made with rolls having a smaller radius than the roughing passes; and in the case of some hard alloys, it is preferred to make the radii progressively smaller toward the exit end, in order to obtain effective reductions in thickness without increasing the roll separating force.

The block 31 is supported by the mill housing beam 7 through the intermediary of

wedges

34 and 35, the position of which is adjustable, in order to provide screwdown means for the rolls 3a.

The last rolling instrumentality is the planishing die 36 shown in more detail in FIG. 10. The concave arcuate face of this die is exactly parallel to the orbit of the roll 2, and in this way each passage of a roll 2 irons out whatever ridges were left by individual contacts of the rolls 3a, so that the exiting strip la has a smooth surface, and is of even gauge.

The planishing die 36 is backed by the same block 31 and is free to slide forward with the movement of the strip 1a during passage of a roll 2, in an arcuate recess 31a which is parallel to the working face of the die.

The forward movement of the die block 36 is resisted by springs 37 which push the block back to its original position where it abuts against a suitable channel 38 provided in the backing block 31. The basic structure shown in FIG. 10, comprising the channel 38 and spring 37, may be used in the embodiment of FIG. 2, as indicated heretofore.

In the mill shown in FIG. 7, as well as in the one shown in FIG. 6, the workrolls 2 which are antipodal to the rolls 2 which are in engagement with theworkpiece l, are in rolling contact with the beam 7' of the mill housing, preferably through a hardened steel liner 39, so as to assist the backing roll 17 in resisting deflection under the influence of roll separating forces, even when rolling very wide strips.

Since the mill shown in FIG. 7 has a very long rollbite, it is possible to use edging rolls 40 for feeding the workpiece I. The edging rolls have a pushing force considerably smaller than thefeedrolls shown in FIG.. 6, but it is sufficient for this application. On the other hand, hot-working of the edges ahead of the action'of the work and anvil rolls, is very beneficial in that it protects the workpiece against the development of edge cracks.

The existing strip la is intercepted by a pair of pinch rolls 52, 52 which, immediately after the leading end of the strip la has entered, turn to rolling position, so as to deflect the strip la vertically. A second pair of pinch rolls 41, 41 then force it to plunge into a nonoxidizing cooling bath 42, preferably of a low melting point metal, such asa eutectic mixture of lead and-bismuth, which has a melting temperature substantially below the oxidizing temperature of steel.

The bath 42 is situated in a tank 43, and the metal is circulated by being let out through the opening 44, passed through a cooling system (not shown) and returned through the opening 45.

In order to prevent oxidization of the strip la during passage through the rolling instrumentality, a hood 46 is attached to the mill housing and has its lower end submerged in the bath 42. For added protection, an inert gas is admitted through the opening 47.

The strip 1a is suitably guided through the bath 42 and into the exit pinch rolls 48, 48 in a condition in which it can directly enter a cold rolling instrumentality, such as a fouror more-stand tandem mill 49, where it can be reduced directly to light gauges, such as steel sheets, and coiled continuously on a carousel coiler 50, after severing the coil by a flying shear 51, when the coil has reached the required diameter.

The rolling instrumentality as shown in FIG. 7 and in FIG. 6 has the added advantage that when the trailing end of the workpiece 1 leaves the edging feeding rolls 40 and 19 respectively, the driven anvil rolls 3 are capable of taking over further feeding of the trailing end and controlling its progress through the mill, without the necessity of using a succeeding slab' to push it through, and without danger that the mill may be damaged by too fast progress of the slab. This is because the slab, while hot, still has some residual elasticity left, and tends to spring back against the driven anvil rolls. In this way, the rolling of each slab is independent of the next one, which is highly valuable especially for alloy into the mill. Here each successive slab (workpiece) crest, during its operation contact with said workroll,

can be fed into the mill at the exact time when it is ready for rolling, and not at the time when it must follow and push the trailing end of the preceding slab.

It will be understood that numerous modifications may be made without departing from the spirit of the invention. Therefore no limitation not expressly set forth in the claims is intended and no such limitation should be implied.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Process of reducing the thickness of an elongated workpiece by plastic deformation which includes the steps of causing a beam-backed work roll concurrently to traverse, and gradually approach, an anvil comprising a pluralityof rounded crests disposed parallel to said work roll and capable .of a small amount of reciprocatory movement in the direction of travel of the workpiece while the work roll is in operative engagement with said workpiece, and back while the work roll is out of engagement therewith, while feeding said workpieceinto the space between said roll and said anvil by extraneous means engaging the non-reduced portion of the workpiece.

2. The process of claim 1 in which each consecutive is permitted to move slightly forward in the roll bite, following the surface velocity of the workpiece while in operating contact with it.

' 3. The process of claim 2 in which said crests of the anvil are returned to their original position before their next operating cycle.

4. The process of claim 3 in which said anvil is divided into sections, each containing one crest, and thesesections are individually returned to their original positions after their operating contact with the workroll.

5. The process of claim 2 in which the workroll, when approaching the end of each operating cycle, continues to move forward, while staying equidistant from said anvil, over a length exceeding the distance betweendeformation produced by two neighboring crests, and in which the surface of the anvil is flat over said distance so as to iron out differences in thickness of the workpiece produced by 'said crests.

6. The process of claim 4 in which the workroll, when approaching the end of each operating cycle, continues to move forward, while staying equidistant from said anvil, over a length exceeding the distance between deformation produced by two neighboring crests, and in which the surface of the anvil is flat over said distance so as to iron out differences in thickness of the workpiece produced by said crests.

7. The process of claim 5 in which the radii of curvature of the consecutive crests gradually diminishes, beginning with the large radius to produce a deeper penetration of rolling deformation into the workpiece, and decreasing to' a small radius to increase the elongating ability of the apparatus as the thickness of the workwhile in contact with such rollers during deformation, better to control the advancing velocity of the workpiece, especially after its trailing end has left the feeding means.

9. The process of claim 8 in which the path of the workpiece through the said reducing instrumentality is an arc of a circle, with the workrolls orbiting uniformly around a backing roll, so that the residual elasticity and tendency to spring back of said backing roll permits said driven anvil rolls better to control the forward movement of the trailing end of the workpiece.

10. Apparatus for reducing the thickness of an elongated workpiece, comprising an anvil having an operating face constituted by a plurality of parallel rounded crests separated by valleys and capable of a small amount of reciprocatory movement in the direction of travel of the workpiece while the work roll is in operative engagement with said workpiece, and back while the work roll is out of engagement therewith, at least one beam-backed work roll having its axis parallel to said crests, said work roll being opposed to, and cooperating with said anvil, and having means to move it in a working stroke, lengthwise of the workpiece and normal to its axis, in the direction of travel of the workpiece only, while retaining said parallelism, in a path gradually converging on said anvil up to the point where the workpiece has been reduced to the required thickness, and then diverging from said anvil for a return stroke out of contact with the workpiece, and means for engaging the workpiece ahead of said anvil and causing it to advance into the bite between said anvil and work roll.

11. The apparatus of claim 10, wherein a rigid base is provided to support said anvil, there being a friction reducing bearing surface at the interface therebetween for minimum resistance to forward movement of said anvil, said anvil being arranged to permit forward movement a distance approximately equal to the elongation of the workpiece during each complete operating stroke of said workroll, and means to return said anvil to its original position for a succeeding stroke.

12. Apparatus according to claim 11, wherein said anvil is divided into a plurality of segments, each having a crest on its operating face and a bearing on its opposite face, with enough clearance between said segments to give each segment room to rock upon said base, dur- 1 ing each operating engagement with the workpiece, ap-

proximately the distance by which the workpiece is elongated during said engagement, and means urging it to return to its original position before the beginning of a succeeding engagement.

13. Apparatus according to claim 12, wherein said last named means are springs.

14. Apparatus according to claim 12, wherein said segments are cylindrical rolls.

15. Apparatus according to claim 11, wherein the radii of curvature of the consecutive crests diminish as the thickness of the workpiece diminishes down the rollbite, for most effective rolling conditions.

16. Apparatus according to claim 10, wherein the workroll describes a curvalinear path, and wherein the operating face of the anvil follows a line parallel to that path while gradually converging upon it.

17. Apparatus according to claim 16, wherein the path of the workroll is a closed orbit, and means are provided to drive said workroll around said orbit at substantially uniform speed.

18. Apparatus according to claim 15, wherein said crests are segments of cylindrical rolls jointly constitut' ing an anvil.

19. Apparatus according to claim 18, wherein the cylindrical rolls of the anvil are backed by rotatable supports disposed along two generants of each roll thereby permitting them to rotate following the advance of the workpiece through the rollbite.

20. Apparatus according to claim 14, wherein the cylindrical rolls of the anvil are backed by rotatable supports disposed along two generants of each roll thereby permitting them to rotate following the advance of the workpiece through the rollbite.

21. Apparatus according to claim 19, wherein drive means are provided for each anvil roll to rotate it at least at the momentary surface velocity of the workpiece while the workroll is in operating engagement with it.

22. Apparatus according to claim 21, wherein the diameters of consecutive anvil rolls are progressively smaller, while the drive means are arranged to provide for progressively higher surface velocities approximately in proportion to the gradually decreasing thickness of the workpiece, down the rollbite.

23. Apparatus according to claim 17, wherein said anvil is divided into zones, the first zone having backed anvil rolls, followed by a second zone beginning about halfway down the rollbite and composed of crest segments, followed by a third zone in which a smooth, short anvil is disposed parallel to the workroll path, said short anvil being adapted to iron out surface undulations on the workpiece produced by the individual crest contacts.

24. Apparatus according to claim 19, wherein said anvil is divided into zones, the first zone having backed anvil rolls, followed by a second zone beginning about halfway down the rollbite and composed of crest segments, followed by a third zone in which a smooth, short anvil is disposed parallel to the workroll path, said short anvil being adapted to iron out surface undulations on the workpiece produced by the individual crest contacts.

25. The process of claim 9, wherein the workpiece after hot reduction into strip but before its surface has begun to oxidize, is contacted by a cooling medium which initially reduces the surface temperature thereof below oxidation temperature, and then continues to abstract heat therefrom until the temperature of its whole mass is below oxidation temperature.

26. Apparatus according to claim 16, wherein a fluidized granule bath is placed in the path of the hot strip emerging from the reducing apparatus, said fluidized granules being continuously circulated in contact with a cooling medium and thence into contact with the hot strip.

27. Apparatus according to claim 16, wherein guide means are provided to direct the hot reduced strip into and through a non-oxidizing bath, to reduce its temperature below oxidation temperature.

28. Apparatus according to claim 17, wherein an additional backing beam is provided, said additional backing beam having an inner surface concentric with said backing roll, and being disposed in antipodal relation to the driven backing roll, so as to contact those workrolls which are opposite to those in working engagement with the workpiece.

29. In a cyclic mill for the single pass reduction of a a fixed axis parallel to the said work roll. slab to strip gauge, at least one beam-backed work roll Apparatus according to Claim 29, wherein the arranged to converge upon said slab in an arcuate path, and a beam backed multimml bed Opposing the action working face of each of said tools lS of arcuate cross of said work roll, said bed being composed of pressing 5 Section tools, each of which is arranged to be swingable around

Claims

1. Process of reducing the thickness of an elongated workpiece by plastic deformation which includes the steps of causing a beam-backed work roll concurrently to traverse, and gradually approach, an anvil comprising a plurality of rounded crests disposed parallel to said work roll and capable of a small amount of reciprocatory movement in the direction of travel of the workpiece while the work roll is in operative engagement with said workpiece, and back while the work roll is out of engagement therewith, while feeding said workpiece into the space between said roll and said anvil by extraneous means engaging the non-reduced portion of the workpiece.

2. The process of claim 1 in which each consecutive crest, during its operation contact with said workroll, is permitted to move slightly forward in the roll bite, following the surface velocity of the workpiece while in operating contact with it.

3. The process of claim 2 in which said crests of the anvil are returned to their original position before their next operating cycle.

4. The process of claim 3 in which said anvil is divided into sections, each containing one crest, and these sections are individually returned to their original positions after their operating contact with the workroll.

5. The process of claim 2 in which the workroll, when approaching the end of each operating cycle, continues to move forward, while staying equidistant from said anvil, over a length exceeding the distance between deformation produced by two neighboring crests, and in which the surface of the anvil is flat over said distance so as to iron out differences in thickness of the workpiece produced by said crests.

7. The process of claim 5 in which the radii of curvature of the consecutive crests gradually diminishes, beginning with the large radius to produce a deeper penetration of rolling deformation into the workpiece, and decreasing to a small radius to increase the elongating ability of the apparatus as the thickness of the workpiece decreases.

8. The process of claim 1 in which at least the first number of said crests are cylindrical rollers, some of which, at least, are driven at a speed at least approximately equal to the surface speed of the workpiece while in contact with such rollers during deformation, better to control the advancing velocity of the workpiece, especially after its trailing end has left the feeding means.

12. Apparatus according to claim 11, wherein said anvil is divided into a plurality of segments, each having a crest on its operating face and a bearing on its opposite face, with enough clearance between said segments to give each segment room to rock upon said base, during each operating engagement with the workpiece, approximately the distance by which the workpiece is elongated during said engagement, and means urging it to return to its original position before the beginning of a succeeding engagement.

13. Apparatus according to claim 12, wherein said last named means are springs.

18. Apparatus according to claim 15, wherein said crests are segments of cylindrical rolls jointly constituting an anvil.

29. In a cyclic mill for the single pass reduction of a slab to strip gauge, at least one beam-backed work roll arranged to converge upon said slab in an arcuate path, and a beam-backed multi-tool bed opposing the action of said work roll, said bed being composed of pressing tools, each of which is arranged to be swingable around a fixed axis parallel to the said work roll.

30. Apparatus according to claim 29, wherein the working face of each of said tools is of arcuate cross section.