Metal rolling process

<td> March 20, 1945.</td><td> H. BLOUNT ET AL</td><td> 2,371,671</td>

<td></td><td> METAL ROLLING PROCESS</td><td></td>

<td></td><td> Filed March 23, 1943</td><td> 2 Sheets-Sheet 1</td>

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. INVENTORS

H Bloukt C.

BY

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March 20, 1945.

H. BLOUNT ET AL

METAL ROLLING PROCESS

Filed March 23, 1943

2,371,671

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INVENTORS e H. Blount C. V. Lundeen

E7TTONNEY

Patented Mar. 20,1945

2,371,671

UNITED STATES PATENT OFFICE

2,371,671

METAL ROLLING PROCESS

Harry Blount, Baltimore, and Carl V. Lundeen, Towson, Md., assignors to Western Electric Company, Incorporatqd, New York, N. Y., a corporation of New York

Application March 23,1943, Serial No. 480,154

Claims.. (CI. 80—60)

This invention relates to metal rolling processes, and more particularly to processes for rolling continuous lengths of metal into strips.

The customary method of making strip is to reduce slabs by successive fiat rolling operations β wherein the size of the pass is decreased in each successive roll. This method necessarily results in both a lateral spread and an elongation of the metal.

In the past metal has been reshaped, when a 1® lateral spreading of the metal was desired, by passing the metal through a series of rolls which exert pressure against the thinnest section thereof. As pressure is applied to this section, it decreases in thickness and the metal flows later- ¹⁸ally, with a considerable amount of elongation. However, in this operation the thin section is put under a substantial tension by the application of pressure thereon, which may result in a rupture or break thereof. 20

The object of this invention is to provide new and improved processes for rolling metals.

In general, the invention comprises the process of reshaping a continuous length of metal by passing it through a series of forming rolls, and ⁸⁸therein applying pressure to the metal so as to cause lateral spreading, yet not placing the section being rolled under tension sufficient to cause a rupture or break therein.

Additional features and advantages of the in- 30 vention will become apparent from the following detailed description of a. specific embodiment thereof, when read in conjunction with the accompanying drawings, in which

Fig. 1 is a cross-sectional view of the metal 35 to be shaped;

Fig. 2 is a cross-sectional view of the metal being shaped, showing fragments of the rolls wherein the first deformation occurs;

Figs. 3, 4 and 5 are cross-sectional views of the 40 metal being shaped, also showing fragments of the successive rolls wherein the shaping is done;

Fig. 6 is a cross-sectional view of the metal in its final size and shape, also showing fragments of the rolls wherein the metal.is so shaped; and ⁴⁵

Figs. 7 to 13, inclusive, are cross-sectional views similar to those shown in Figs. 1 to 6, which illustrate a modified method of rolling metals embodying the invention.

The particular embodiments of the invention 50 disclosed in the accompanying drawings are particularly applicable to the rolling of copper rods to form fiat strips. In. the embodiment of the invention shown in Figs. 1 to 6, inclusive, a cold copper rod 10 having a circular cross-section 55 (Fig. 1) is passed between rolls ii—Ii (Fig. 2) provided with similar shaping surfaces formed of relatively narrow, parallel middle surfaces 12—12 and inclined side surfaces 13—13 and 14—14 intersecting therewith to form angles A—A, The rod 10 is shaped by the rolls 11—Ii into a continuous length of metal having a dumbbell-shaped cross-sectional area indicated by the numeral 15. The area 15 comprises a flat middle section 16 having cylindroidal portions 17—Π at the ends thereof and is approximately equal in size to the cross-sectional area of the original rod 10.

The length of metal having the cross-sectional area 15 is then passed between rolls 18—18 (Fig. 3), having similar, shaping surfaces formed of parallel middle surfaces 19—19, which are wider than the middle surfaces 12—12 of the rolls ii—Ii, intersected by .inclined side surfaces 20—20 and 21—21 to form angles B—B, which are greater than the angles A—A (Fig. 2). The rolls 18—19 change the metal from a bar having the cross-sectional area designated by the numeral IS into one having a cross-sectional area designated 22, comprising a fiat central section 23 having cylindroidal portions 24—24 at the ends thereof. The central section 23 is longer than the central section 16 of the cross-sectional area IS, and the cylindroidal portions 24—24 are smaller than the cylindroidal portions 17—17 of the area

15. Nevertheless, the cross-sectional area 22 is approximately equal to that of the original rod 10.

The length of metal is next passed through rolls 25—25 (Fig. 4) having similar shaping surfaces formed of parallel middle surfaces 26—29. which are wider than the middle surfaces 19—49 of the rolls 13—18, and inclined side surfaces 27—27 and 28—28 which intersect therewith to form angles C—C which are greater than the angles B—B (Fig. 3). The rolls 25—25' form the metal passing between them into a continuous length having a cross-sectional area indicated by the numeral 29, comprising an elongated fiat central section 30 having cylindroidal portions 31—31 at the ends thereof. The cross-sectional area 29 is roughly equal to that of the original rod 10 and also to the cross-sectional area 22, although the central section 30 is longer than the corresponding section 23 of the area 22 and the cylindroidal portions 31—31 are smaller than the corresponding portions 24—24 of the area 22.

The length of metal is then passed between rolls 32—32 (Fig. 5) having similar forming faces comprising parallel middle surfaces 33—33 and inclined side surfaces 34—34 and 35—35. The middle surfaces 33—33, which are wider than the

2,371,671 middle surfaces 26—26 of the rolls 25—25 (Fig. 4), are intersected by the inclined side surfaces 34—34 and 35—35 to form angles D—D which are greater than the angles C—C (Fig. 4). The rolls 32—32 convert the cross-sectional area 29 of the 5 metal into a cross-sectional area designated 36 which is still' nearly equal to that of the rod 10 and which comprises a flat central portion 31 having flattened cylindroidal portions 38—38 at the ends thereof. 10

The metal having the cross-sectional area 36 is then passed between rolls 39—39 (Fig. 6) having flat parallel shaping faces 40—40. The rolls 39—39 form the metal into a continuous strip having a rectangular cross-sectional area desig- 15 nated 41, which is the width of that desired in the final product. The material may be worked further by conventional methods if it is desirable to reduce the thickness of the material which emerges from the rolls 39—39. 20

It is to be noted that the cross-sectional area of the metal being shaped is kept as nearly constant as possible until the metal enters the shaping rolls 32—32, although the cross-sectional shape of the metal is changed as it advances 25 through the successive preceding rolls. Even when the material has passed through the rolls 32—32, its cross-sectional area is still almost as great as that of the original rod 10.

In practicing the improved process, the cir- 30 cular copper rod 10 (Fig. 1) is first passed between rolls II—II (Fig. 2) wherein the shaping surfaces 12—12, 13—13 and 14—14 thereof exert pressure upon the rod to form a continuous length of metal having a dumbbell-shaped cross- 35 sectional area 15 comprising a flat section 16 with cylindroids IT—17 at the ends thereof. Due to the shape of the rolls 11—11 it is possible to get a maximum of lateral spread of the rod with a minimum of elongation, while the resulting cross- 40 sectional area 15 is approximately equal to the cross-sectional area of the rod 10.

The metal now having the cross-sectional area 15 is then passed between the rolls 18—18 (Fig. 3). Since the. width of the surfaces 19—19 of 45 the rolls 18—18 is greater than that of the surfaces 12—12 of the rolls II—II (Fig. 2), the surfaces 19—19 are necessarily wider than the central flat portion 16 of the cross-sectional area 15. Such being the case, and as the angles 50 B—B are greater than the angles A—A, the pressure exerted by the rolls 18—18 through the shaping surfaces 19—19, 20—20 and 21—21 will be applied mainly upon the inner sides of the cylindroids 11—17, resulting in a lateral spread 55 of the cylindroids with a very small amount of elongation of the metal.

Thus, the rolls 18—18 form the metal into a length having the cross-sectional area 22 composed of a flat section 23, which is wider than 60 the flat section 16 (Fig. 2), with slightly flattened cylindroids 24—24 at the ends thereof. The cross-sectional area 22 is approximately equal to the cross-sectional area of the rod 10. Since the shaping pressure of the rolls 18—18 65 is exerted principally upon the cylindroids IT—17 (Fig. 2), the flat center portion 23 (Fig. 3) is not put under any tension likely to rupture or break it.

After having been acted upon by the rolls 70 18—18, the metal is next passed between the rolls 25—25 (Fig. 4). The width of the surfaces 26—26 of the rolls 25—25 is greater than that of the flat section 23 of the cross-sectional area 22, and the angles C—C are greater than the 75 angles B—B. As a result, the pressure exerted by the rolls 25—25, through the shaping surfaces 26—26, 27—27 and 28—28, will likewise be applied mainly upon the inner sides of the cyl> indroids 24—24, which results in a lateral spread of the cylindroids with little elongation of the metal.

Hence, the rolls 25—25 form the metal into a continuous length having the cross-sectional 0 area designated 29, which is made up of a flat section 30 which is wider than the flat section 23 (Fig. 3), with further flattened cylindroids 31—31 at the ends thereof, while the cross-sectional area 29 is almost equal to the cross-sec5 tional area of the original rod 10. As the forming pressure is exerted mainly upon the cylindroids 24—24 (Fig. 3)., the flat portion 30 is not subjected to any tension sufficient to injure or rupture, the metal.

From the rolls 25—25 the metal. is ' passed through the rolls 32—32 (Fig. 5). The surfaces 33—33 of the rolls 32—32 are wider than the flat section 30 of the cross-sectional area 29 and the distance between the surfaces 33—33 is less :5 than the thickness of the section 30, while the angles D—D are greater than the angles C—C (Fig. 4). In consequence, the rolls 32—32, acting through the shaping surfaces 33—33, 34—34 and 35—35, will exert pressure On both the flat 10 central section 30 and the cylindroids 31—31, resulting in a further lateral spread and some elongation of the metal.

The metal is formed by the rolls 32—32 into a length having the cross-sectional area indi15 cated by the numeral 36. This area comprises a flat section 37, which is wider and thinner than the flat section 30, and has further flattened cylindroids 38—38 at the ends thereof. However, the cross-sectional area 36 is still almost as 10 great as that of the original rod 10. As the shaping pressure is .exerted principally upon the cylindroids 31—31 (Fig. 4) the flat portion 37 is not subjected to any tension likely to damage the metal.

a The metal is finally passed through the rolls 39—39 (Fig. 6). Here the pressure is first applied through the flat shaping surfaces 40—40 against the flattened surfaces of the cylindroids 38—38 (Fig. 5). This results in a further lateral spread 0 of the metal together with a considerable amount of elongation until the portions 38:—38 are flattened down to the thickness of the center portion 37 when the rolls 39—39 flatten the entire body of the metal, primarily through elongation, to the final thickness desired. This produces a flat strip having a rectangular cross-sectional area designated 41 and having the width desired in the finished product. If it is desirable to reduce further the thickness of the strip, this may 0 be accomplished by conventional methods and apparatus well known to the art. The above outlined method has been found to be especially suitable for shaping a A diameter copper rod into a strip having a final width of .980” and a final thickness of .010”.

Figs. 7 to 13, inclusive, show a series of steps which may be used when, it is desired to obtain a maximum amount of lateral spread with a minimum amount of elongation of any given di0 ameter rod. For example, by using this process it is possible to obtain a strip having a final width of from about 1% to about V/2” from a A” diameter rod without subjecting the rolled section to a tension likely to injure it.

In accordance with this process, the angles

2,371,871 formed by the intersection, of the flat parallel middle sections and the inclined sides of the shaping surfaces of the rolls are constant in the successive spreading rolls, and the distance between the flat parallel middle sections is also 5 substantially constant. The shaping surfaces of the rolls are so formed as to cause a maximum of lateral spread of the metal with a minimum of elongation.

It will be obvious from an examination of Figs. 10 7 to 13, inclusive, that the metal is passed through successive rolls wherein a circular rod is first converted into a continuous length of metal having a dumbbell-shaped cross-section and thereafter pressure is mainly exerted upon the cylin- is droids at the ends of this cross-sectional area to cause a lateral spread thereof. This results in the production of an ever widening flat central section of the metal with cylindroids of diminishing sizes at the ends thereof. The cross-sectional 20 area of the'metal is substantially constant as it passes through successive rolls, although the cross-sectional contour is varied. The metal is finally passed through a pair of rails having flat shaping surfaces, wherein lateral spread apd 25 elongation of the metal both result, to form the metal into a strip of the desired width and having a rectangular cross-section.

Obviously, it may be necessary to include annealing steps in the above described processes. 30 The number of such steps, and the points at which they occur, will be governed by the type and size of the metal being shaped and the final size and shape desired. For instance, in the foregoing processes it may be necessary to anneal 35 the metal after it passes through each pair of rolls, or after it passes through every second pair of rolls.

This invention is not limited to the rolling of circular rods, but may also be employed to form 40 strips from symmetrical rods having square, hexagonal, octagonal or other cross sections. Obviously, the number of rolls may be varied, as may also the shape and size of the roll shaping surfaces, depending on the type and size of 45 the continuous lengths of metal to be shaped and the final size and shape desired.