US2960764A

US2960764A - Method of making metal shapes having thin webs

Info

Publication number: US2960764A
Application number: US804936A
Authority: US
Inventors: Reymond M Reichl
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-04-08
Filing date: 1959-04-08
Publication date: 1960-11-22
Anticipated expiration: 1977-11-22

Description

` R. M. RElcHL 2,960,764 METHOD oF MAKING METAL sHAPEs HAVING THIN WEBS Nov. 22, 1960 Original Filed Aug. 9. 1954- l I I l 1. l l l l l l I INVENTOR fj REYMa/va M. RE/c/L r'netal shape.

duce such shapes because the resistance to transverse flow Vdiameter of the metal shape.

desirable.

United States Patent-O METHOD F MAKING METAL SHAPES HAVING l THIN WEBS Reymond M. Reichl. 110-11 70th Road, Forest Hills, N .Y.

Continuation of abandoned application Ser. No. 448,060, Aug. 9, 1954. This application Apr. 8, 1959, Ser. No. 804,936

. 9 Claims. (Cl. 29-424) l Thisinvention relates to a method of making a metal shape which has a thin web surrounded by a peripheral T he preferred embodiment of the invention is a method for producing circular metal bodies of substantially fiat shape with profiled cross section, with a large jpart of the at area of the body comparatively thin.

Metal shapes or bodies of the character indicated are known as Wheel blanks and gear blanks, and they have been produced by die-forging, usually in a hot state; or by `die-forging and subsequent rolling in a so-called wheel rolling mill. Such methods have beenused principally for the production of low-carbon steel wheels, and

Yof related shapes where the final thickness of the body ,and the thickness of the rim are rather substantial as .compared with the overall diameter of the finished circular body.

The present methods of manufacture will not produce a metal shape having a diameter which is very large in proportion to the thickness of the web and rim of the Forging methods cannot be used to proof the metal increases at a progressively higher rate as n the section becomes thinner and the transverse cross section correspondingly larger. Where webs are to be manufactured with a thickness less than that which can be forged, it has been necessary to obtain the reduced thick- `ness by machining. With the advent of alloy steels of high heat resistance, the machining of any substantial ,thickness from the web is extremely costly and imprac- .tical It is an object of this invention to provide `an im- .proved method for making metal shapes which have webs surrounded by peripheral rims, and which have a web thickness which is small in comparison with the The invention is intended primarily for making the alloy steel, rimmed discs; but

,it will be understood that the invention can be used for 4making other parts and when rolling metal other than ferrous metal.

One advantage of the invention is that it can be used for shaping very hard metal, or metal or alloys which are resistant to deformation, even at elevated temperatures; and'that the metal shape can be brought close to the Yiinal desired dimensions at a minimum of time and cost.

In the preferred embodiment of the invention, the final ,step of the method includes a forging step which counteracts any irregularities in the metal liow in previous rolling operations, and which compensates for rounding of the edges of the work piece when such rounding is un- In accordance with one feature of the invention a work piece blank is provided, having substantially the weight 'of the finished metal shape, and preferably made by dieforgng or under a hammer. This blank has already the general configuration of the final shape and of the crosssectional profile, but it is thicker and therefore of considerably smaller area so as to be more easily produced, even if its material is highly resistant against deformavassembly shown in Figure 4;

2,960,764 Patented Nov. 22, 1960 ice tion at elevated temperature. Inserts are provided from a less expensive material for filling Vthe space on opposite 4sides of the web of the work piece blank to a depth substantially flush with the opposite side edges of the rim ofthe work piece. The work piece blank is heated to hot-forming temperature, the inserts are heated usually to a different temperature and are assembled with the work piece blanks so as to form a composite body presenting uninterrupted upper and lower faces without recesses or protruding portions. The composite body or assembly is rolled in a rolling mill with cylindrical rolls and subjected to such a Ipass schedule, and elongated in different directions in different passes, as to obtain a composite body of small overall thickness and of a large fiat area. The inserts are then removed and the finished shape has the desired thickness and outline, and is much thinner than could be obtained under a press orrhammer.

---Ot her objects, features and advantages of the invention will appear or bepointed out as the description proceeds. v

vIn the drawing, forming la part hereof, in which like reference characters indicate corresponding parts in -all the views;

Figure l is a sectional view through a work piece blank having a web and rim which are of substantially greater vthickness and diameter than the desired thickness of the `metal shape which is to be made by the method of this invention; p y

[Figure 2 is a filler piece for use on top of .of the work piece blank of Figure 1;

the web Figure 3 is a filler piece for use against the botto face of the web of the work piece blank shown in Figure 1; i

Figure 4 is an assembly view showing the work piece -blankof ,Figure 1 with the filler pieces of Figures 2 and 3 in place and ready for rolling of the composite ltion for a subsequent rolling operation;

Figure 9 is a view similar to Figure 8 showing the outline of the blank after the final rolling;

Figure 10 is a sectional view taken on the line 10-10 of Figure 9;

Figure 11 is a sectional view, similar to Figure 10,

but with the filler pieces removed;

Figure 12 is a greatly enlarged, fragmentary, sectional view showing one way in which the filler pieces are removed from the web; and

Figure i3 is an enlarged, fragmentary, sectional view through a forging die in which the rim of the work piece is shaped in the last step of the invention.

A work piece blank 10 has a web 11 surrounded by a peripheral rim 12. There is a depression 14 in the top surface of the blank 10 .above the web 11 and there is a depression 15 in the bottom face of the blank v10 below the web.

Figure 2 shows a filler piece 18 which is shaped to fit the depression 14 of the work piece blank. Figure `3 shows a filler piece 19 which is shaped to fit the depression 15 of the work piece blank. When these

filler pieces

18 and 19 are located in the

depressions

14 and 15,-respectively, the outside faces of the filler pieces are preferably Hush with the side faces of the rim 12, as shown in Figure 4.

The blank is heated to the required temperature for hot forming, the temperature depending upon the particular metal of which the work piece blank is made. The

filler pieces

18 and 19 may be made by cutting them out of plates of a related but less expensive material. The filler pieces are generally heated separately from the work piece blank and to a lower temperature. This difference in heating makes the metal of the composite body present a similar resistance to hot deformation, and even though the blank 10 is of tougher material than the

filler pieces

18 and 19, the composite body rolls as though made from a homogeneous substance as far as resistance to deformation is concerned.

Another advantage in having the

filler pieces

18 and 19 constructed of different material from the work piece blank 10 is that it prevents their welding to the blank. If required, a substance can be applied to the contact areas of the blank 10 and the

filler pieces

18 and 19 prior to their assembly for the purpose of preventing sticking, galling or welding during the subsequent rolling operations. Such substances are well known and usually consist of an infusable oxide or ceramic carried by a suitable liquid vehicle.

A modified way in which the method of the invention can be carried out, assembles the blank 10 and the

filler pieces

18 and 19 while all of these parts are cold. The filler pieces can be held in place by spot welding. The composite body is heated to a uniform temperature and to the temperature most suitable for the hot deformation of the work piece blank 10. After removing the composite body from the furnace, controlled cooling is applied to the exposed faces of the

filler pieces

18 and 19 to reduce their temperature in order to obtain a body with more homogeneous resistance to deformation during rolling.

'Ihe work piece blank, with the filler pieces in place, is preferably rolled in a mill stand having cylindrical rolls. The mill stand may be a two-high mill, or a three-high or four-high mill stand, or a succession of mill stands if it is desirable not to carry out the entire rolling schedule in one stand.

The opening between the mill rolls, and the consequent reduction in the thickness of the work piece blank, is controlled by means of screwdowns in accordance with conventional rolling practice. The iirst part of the roll schedule reduces the thickness of the work piece blank `and elongates the blank in the direction in which it passes between the rolls of the mill stand. The elongated work piece blank is designated by the reference character 10 in Figure 6.

The work piece blank 10' may be the result of a single pass or several successive passes depending upon the kind of metal of which the blank is constructed and depending upon the adjustment of the mill rolls. The blank 10' is substantially elliptical in outline with the major axis of the ellipse extending in the direction in which the work piece blank passed through the mill stand, and the minor axis of the ellipse extending at right angles to the direction of passage ythrough the mill stand.

In preparation for the subsequent rolling, the work piece blank 10 is rotated through an angle of 90 about an axis extending normal to the top surface of the work piece blank at the center of the ellipse. This turning of lthe work piece blank v10' is represented by Figure 8.

The blank 10 is then passed through a rolling mill stand in the direction of the minor axis of the ellipse. This subsequent rolling increases the length of the minor axis while leaving the length of the major axis substan` tially unchanged so that with suflicient rolling, the work piece blank is restored to a circular outline, as shown in Figure 9. This thinner and circular work piece blank is -designated by'the reference character 10. This restoration of the work piece blank to circular outline is obtained by having substantially the same percentage of reduction while rolling in the direction of the minor axis of Figure 8 as was obtained in the initial rolling which produced the elliptical outline shown in Figure 6.

The elongation, as the term is used herein, is a function of the reduction in thickness of the work piece blank. In the case of a 30% reduction in thickness, of a work piece blank having a length L before the rolling operation, the elongation is:

L man@ When rolling with a pass-schedule necessitating several passes in one direction, and several passes in the perpendicular direction, it is theoretically immaterial, whether all passes are first carried out in one direction, resulting ina strongly elongated ellipse, and followed by the full series of passes in the perpendicular direction, or whether the direction of rolling is changed during rolling, as long as the cumulative amount of the elongation along one direction is equal to the cumulative amount produced in the direction perpendicular to the first. It is also desirable to impart reductions to the blank by rolling it along several directions which are at equal angles to one another around the center of the blank so as to obtain more uniformly worked material provided that the cumulative eliect is such as to result in a round shape.

The results obtained by the rolling operation are afected to some extent by spreading of the material, particularly during the lirst passes when the composite body is vof greater thickness. As a result of the spreading, or transverse flow of the material, the minor axis of the ellipse shown in Figure 6 is slightly greater than the diameter of the work piece blank 10. With some metal there is also an extrusion effect which makes the ellipse of Figure 6 slightly egg-shaped. The pass-schedule can be modified to compensate for the spreading; and if the extrusion effect is substantial with a particular metal, a rolling pass in a reverse direction can be taken.

In the preferred embodiment of the invention the rolling is done with the metal heated, as previously eX- plained; but some metals can be rolled with the composite body in a cool state. Whether done with the metal hot or cool, the final cross section of the work piece blank 10' has a configuration which is generally similar to thatgof the original work piece blank 10, the thickness of the component members having been reduced pro rata and in accordance with the increase in the area of the body. The method is intended for use with work piece blanks of originally circular outline, but this is not essential.

Figure 12 shows a preferred way in which the

filler pieces

18 and 19 are separated from the web 11 after the rolling is completed. A hole or bore 23 is drilled through each of the

iiller pieces

18 and 19 for a depth suicient to reach the web 11. A hydraulic fitting 24 is then welded to the face of each of the

filler pieces

18 and 19. High pressure liquid, such as water or oil, is pumped through the fitting 24 and `forced against the area of the web. This pressure moves the

filler pieces

18 and 19 away from the web and thereby disconnects them from the work piece.

Figure.l3 shows the final step of the process of this invention. After the filler pieces have been removed, the work piece blank 10 is inserted in a forging die having two

elements

31 and 32. As the

elements

31 and 32 arebrought into contact with the work piece 10", the metal of the work piece is caused to llow slightly with a reduction in thickness and a transverse flow of metal in the rim to lill the cavity of the die. This gives the peripheral Aface of the rim the desired contour which is built into the forging die, and the forging compensates 'for the rounding of the face of the 'rim which results from the rolling operation. For most purposes, a rounded edge is not desirable.

This forging operation, illustrated in Figure '13, also compensates for irregularities in the fiow of the metal and makes a minimum of machining necessary where good dynamic balance is essential. The web 11 of the work piece is not deformed by the forging step but serves as a stop for the

elements

31 and 32 of the forging die. A fiash 34 is ordinarily thrown out by the forging operation, in accordance with conventional practice.

Although the invention has been described for the production of a round body with a profiled cross-section it will be understood that the method of this invention can be used also for the production of generally flat bodies of different configuration and outline, such as panels. When so used, a suitable forged work piece blank is produced under a press or a hammer and fitted with inserts and subjected to rolling with cylindrical rolls. The roll pass-schedule has to be established with a view, however, to not only decreasing the overall thickness of the work piece blank but also elongating it in predetermined directions. The influence of spreading and extrusion which occurs during the rolling, can be compensated by suitable modification of the original Work piece blank so as to obtain a body of the desired nal shape, size, and cross-sectional configuration.

This application is a continuation of my allowed application, Serial No. 448,460, filed August 9, 1954, now abandoned.

Other changes and modifications can be made without departing from the invention as defined in the claims.

What is claimed is:

l. The method of making a metal shape having a thin web surrounded by a peripheral rim of substantially greater thickness than the web, which method comprises forming a work piece with a heavy web surrounded by a peripheral rim of substantially greater thickness and less diameter than the intended thickness and diameter of the finished metal shape, filling the space beside the web with material to a level substantially liush with the side of the rim, and radially confined by the rim, rolling the work pieces to a thinner section and elliptical outline by rolling pressure applied simultaneously and directly to the flush surfaces of the rim and filling material, turning the work piece through 90 about an axis extending in a direction substantially normal to the plane of said fiush surfaces and rolling the work piece to a still thinner section and to a substantially circular outline, and then removing the filling from the space beside the web.

2. The method of making a metal shape from a work piece blank having a heavy web surrounded by a peripheral rim of substantially greater thickness and less diameter than the intended thickness and diameter of the finished shape, which method includes placing metal filler pieces, made of different metal from the work piece, in the space beside the web and radially confined by the rim, rolling the work piece and filler pieces to a thinner section and to an elliptical outline by rolling pressure applied simultaneously and directly to the surface of the rim and filler piece, and through the filler piece to the web, turning the work piece filler assembly through an angle of 90 about an axis extending in a direction substantially normal to the plane of the rolled surfaces, rolling the assembly to a still thinner section and until the assembly is again of circular outline, and then removing the filler metal from beside the web.

3. The method of making a metal shape, as described in claim 2 and in which the work piece and the filler metal are heated prior to rolling, and the filler metal is heated to a different temperature from the work piece to compensate for the different rolling characteristics of the different metals.

4. The method of making a metal shape having a thin web surrounded by a peripheral rim of substantially greater thickness than the web, whichmethodcomprises initially forming a work piece blank with a heavy web surrounded by a peripheral rim of substantially greater thickness and less diameter than the intended thickness and diameter .of the finished shape, filling the space across the full width within the rim and on both sides of the web with metal filler pieces that have their outer surface vsubstantially flush with the rim of the work piece, rolling the work piece while highly heated and under pressure to reduce the work piece to a thinner section and an elliptical outline by rolling pressure applied simultaneously and directly to the flush surfaces of the rim and filling material, then rolling the work piece in a direction at right angles to the direction of the original rolling to reduce the section still further and increase the minor axisof the ellipse' until the outline of the work piece becomes substantially circular, and thereafter removing the filler metal.

S. The method of making a metal shape, as described in claim 4 and in which the work piece, after having the filler metal removed, is subjected to a forging operation exerted against the rim to counteract rounding of the peripheral face of the rim by the rolling operations.

6. The method of making a metal shape from a work piece blank having a heavy web surrounded by a peripheral rim, the thickness of both the web and rim being greater than the intended thickness of the final metal shape and the diameter of the work piece being Substantially less than the desired diameter of the metal shape, which method comprises filling the space on both sides of the web with metal filler pieces constructed of different kind of material from the work piece, the metal filler pieces being of substantially the same shape as the spaces beside the web and bounded by planes covering the opposite side edges of the rim, rolling the work piece and fillers to a substantially reduced thickness and elliptical outline by rolling pressure applied simultaneously and directly to the fiush surfaces of the rim and filling material, then cross rolling the work piece to a still thinner section and to substantially circular outline, and thereafter removing the fillers by drilling a hole through each filler as far as the web o-f the work piece, welding a hydraulic fitting to the filler around the hole and removing the filler from the web by the application of hydraulic pressure through the fitting and hole and against the web.

7. The method of making a metal shape from a work piece blank having a heavy web surrounded by a peripheral rim with both the web and rim of substantially greater thickness and less diameter than the intended thickness and diameter of the filler metal shape, which method comprises filling the space across the full width within the rim and on both sides of the web with metal of a different kind from the metal of the work piece, the filler metal being sufiicient to come substantially flush with the side faces of the work piece rim, heating the work piece to a rolling temperature, rolling the work piece in one direction to reduce the thickness of the rim and web by rolling pressure applied simultaneously and directly to the fiush surfaces of the rim and filling material, cross rolling the work piece to reduce the thickness still further and to compensate for the elongation produced by the initial rolling, removing the filler material from both sides of the web, and forging the rim.

8. The method of making a metal shape having a thin web surrounding a center and surrounded by a peripheral rim of substantially greater thickness than the web whereby a side of the rim is elevated above the web, which method comprises making a work piece blank which has the web and peripheral rim both of greater thickness than the intended final dimensions of the metal shape, placing filler metal within the recess defined by the web and peripheral rim and up to a plane iiush with said side of the rim, exerting a rolling pressure against the rim and 'amore-4 7 s web `simultaneously along a straight ,line across lthe. blank andv at locationsprogressively along the blank ina directionfsubstantially normal to said'straight line, maintaining the rolling pressure sufciently high to deform the blank, exerting the rolling pressure against the web through said filler metal that is in said recess and with the filler metal radially confined by the rimaround the entire periphery of the filler metal, continuing the rolling pressure and deforming the thickness of the web and rirn substantially equally, and until they reach the intended dimensions, and after the work piece blank has been rolled to substantially its finished dimensions, removing the filler metal.

9, The method of making a metal shape as described inclaim 8, but with a metal shape in which the peripheral 15 2,655,716

rim is elevated above the web von both sides of the web so thatthere isa recess defined by the web and peripheral rim onboth sides of the metal shape, and in which filler metal is placed in both of the recesses defined by the web and rim and up to the planes flush with the rim on both sides of the metal shape, and rolling pressure is exerted against the filler metal on both sides of the metal shape.

References Cited in the file of this patent UNITED STATES PATENTS 1,060,361 Rea Apr. 29, 1913 2,386,091 Carlson Oct. 2, 1945 2,641,439 Williams June 9, 1953 DelMarinis Oct. 20, 1953