US1909887A

US1909887A - Rolling in a magnetic field

Info

Publication number: US1909887A
Application number: US622335A
Authority: US
Inventors: Otho M Otte
Original assignee: HARRY F PORTER
Current assignee: HARRY F PORTER
Priority date: 1932-07-13
Filing date: 1932-07-13
Publication date: 1933-05-16
Anticipated expiration: 1950-05-16
Also published as: DE627952C; FR758252A; GB422347A; BE397538A

Description

May 16, 1933. o, oTTE ROLLING IN A MAGNETIC FIELD INVENTOR.

R: W Hill!" Filed July 13, 1932 Ala/1 TTORNEYS.

May 16, 1933. o. M. OTTE #909,887

' ROLLING IN A MAGNETIC FIELD Filed July 13. 1932 4 Sheets-Sheet 5 INVENTOR.

$ 144 fTORNEYS.

May 16, 1933. o, M oTTE ROLLING IN A MAGNETIC FIELD Filed July 13, 1932 4 Sheets-Sheet 4 INVENTOR. m 772 @655 .44}, A TTORNEYS.

Patented May 1& 1'933 UNITED STATES OTHO I. OTTE, 0] TARENTUM, PENNSYLVANIA, ASSIGNOR OF ONE-BALI PORTER, OI BRACKENRIDGE,

PATENT OFFICE TO HARRY I. PENNSYLVANIA BOLLIN G IN A. MAGNETIC FIELD a plication filed m 13,

core. materials and include all metals or metal alloys having the characteristics or qualities which render them suitable as core materials.

Other magnetic materials to which. thisinvention is directed are those suitable for use 'inthe make-up of permanent magnets.

{lVhile I have directed my studies primarily to magnetic materials, I believe that the underlying method or procedure hereinafter outlined, if utilized in the manufacture or treatment of metallic materials other than magnetic materials, will produce certain desirable qualities or characteristics therein, or at least enhance the value of such materials for use in situations where the maximum of certain qualities ortcharacteristics is desired. i a

The term metallic material as used herein is intended to include metals and metal alloys and particularly ferrous metals and alloys having a ferrous base, but is not intended to exclude other metals or alloys.

Critical temperature-range as used herein designates that range .of temperatures through which a magnetic material passes when changing from the non-magnetic state to the magnetic state and vice versa, and includes that temperature at which molecular v rearrangement within any metal or metal alloy occurs.

The properties of all metallic materials, with which I am familiar, undergo fundamental changes when the material-is heated to a temperature well above its critical temperature range and allowed to cool-down to a point below said range and it is my belief 1932. Serial No. 622,835.

that these changes occur because of molecular rearrangement Within the material.

At temperatures above the critical temperature range, all metallic materials known to me are non-magnetic." At temperatures below the critical temperature range many metallic materials are magnetic and the" magnetic properties of such materials become more pronounced the lower the temperature of the material. I I Hot working, such as rolling or other forgmg of metallic materials is preferabl carried on (at least to a major extent while the material is at a temperature well above its critical temperature range.

This invention fundamentally consists in sub ecting metallic materials to the influence of a-relatiyely strong magnetic field and while so influenced in-rolling or otherwise forgmg the same during the period while it is within its critical temperature range. Spethe invention consists in rolling or otherwise forging a metallic material throughout a period which starts at a point well above its critical temperature range and continues until the temperature of the material has dropped to .a point below its critical temperature range and during such working, in subjecting the material to the influence of a relatively strong magnetic field.

While the treatment thus broadly described is applicable to the manufacture and/or finishing of various metals and metal alloys I am primarily interested in magnetic materials'used in certain parts of electrical apparatus having alternating magnetic fields such as transformer cores, pole pieces and magnetic kinds. These are preferably or necessarily of laminated structure and sheets or plates therefore are usually employed in building up the same. g The material used for transformer cores and to a lesser extent that used in alternatlng current genera-tors must be characterized poles of various armature cores, 1,

brittleness.

.the provision of a method characteristics or An object of this invention is the provision of a method of improving metallic materials for use as magnetic materials.

Another object. of this invention is the provision of a'method of manufacture for or 'the production of magnetic ma-' terials either in the form of sheets or plates for use in the make-up of parts of electrical apparatus or as permanent magnets f which latter use the material will not be in the form of laminae, whereby such materials are greatly improved for the uses to which they are tobe put.

A still further object of this invention is the provision of a method of treatment whereby finished or semi-finished sheets or plates of magnetic material such as silicon steel may have their watt-loss values materially decreased below the values of the best magnetic material manufactured today and 'with'which I am familiar. A still further object of this invention is whereby desirable qualities of alloys in the form 'of sheets, plates, tubes, bars, wire, etc., may be obtained therein without affecting the material of such products in any undesirable manner. s

A still further and more, limited object of this invention'is to providea method whereby the resistance to corrosion of certain alloys maybe increased. Some of these alloys are knownto the" trade as Allegheny .Metal, KA-2, 18-8 and Enduro.

These aswell as other objects which will appearto those skilled in the arts to which this invention relates, I. attain by means of the method or treatment or processing broadly described above and hereinafterspecifically described in. connection with the manufacture of sheet material and that for use in making up permanent magnets.

Since the method of my invention broadly consists in performing work (such as rolling or forging) on a metal or metal alloy while the same is. lowering in temperature from a temperature above the. point or range at which molecular rearrangement therein oc-v curs to a temperature belowsuch pointf-or range and whilesubjected to the. influence 'of a relatively strong magnetic flux or field, it (the method) is out in numerous ways.

Since standard methods of hot rolling or forging and standard apparatus for'heating the material and working, rolling or hammering the same, as the case may be, can be utilized, it is only capable of beingcarried necessary to provide the relatively strong correlate the same to the rolls or hammer and thework done thereby (such as reducing the gauge of partially finished sheet or plate material or the finishing of a forging or obtaining the final pass in a bar mill or tube mill) that such work takes place within such magnetic field, or so nearly adjacent thereto that the material being hot worked is beneficially influenced by said field or flux.

In order that a complete understanding of m invention in connection with certain types be had, I have included certain drawings in this application which illustrate certain apparatus by means of w ich the method of my invention may be carried into effect. For instance, I have illustrated a two-high finishing mill equipped for subjecting to the influence of a relatively strong magnetic field, packs of semi-fini ed magnetic sheet material.

I have also schematically illustrated two stands of a strip finishing mill equipped for racticing my, method as well as a hammer or performing forging operations and equi ped for, carrying out my method. In the rawings: I I a Figure 1 is a view in front elevation of a two-high finishing mill equipped for carrying out my invention;

Fig. 2 1s a view in end elevation of said mill, as seen looking from right .to left in Fig 1; Y

ig. 3 is a more or less diagrammatic view and represents the reducing rolls of two stands arranged in tandem adapted for the rolling of strip material and being equipped for the practice of my invention;

Fig. 4 is a view in front elevation looking toward the entrance side .of one of the pair of rolls embodied in-the two stands of Fig. 3;

Fig. 5 is a more or less diagrammatic view illustrating a pair of'reducing rolls and the mechanisms for feeding material to'and from a pair of rolls equipped for the practice of my invention; and i Fig. 6 is a. pictorial view illustrating a forging hammer so equipped as to be suitable for the practice. of my invention upon forg- .%l1en plates or-sheets' are to be rolled or finished in accordance with my invention, may use a paratus such as that disclosed in Figs. 1 an 2, wherein is disclosed a two-high mill, generally of conventional type, suitable for rolling or' finishing either sheet packs or [plates as the case may be.

g It is in the finishing pass or passes that I preferably utilize my'invention, because it is in these passes where the benefits derived from the methodof my invention are most pronounced.

' When practising ing pass-or passes in magnetic field and to so the method in the finishthe rolling of 'either 'tem sheets or plates, the plates or packs are raised, as is now. ordinarily done, to rollin tem rature, that is, a temperature above t e critical rature range of the material. e apparatus of Figs. 1 and 2 comprises a mill housing made up of the customary parts 10 and 11, each rovided with the customary window '12, r0 1

neck brasses

13 and 14 mounted within the windows and rolls 15 and 16. v I

The roll neck brasses being non-magnetm, Egovide and maintain substantial air aps tween the roll necks and the mill housings, thus largely confining the magnetic flux before referred to within the rolls, the necks and the material being worked on by the rolls.

In such a two-high mill which is ordinarily of the jump variet the lower roll is the driven roll and in t e case of the mill 1lll1S- trated in Figs. 1 and 2, a non-magnetic coupling member 17 is provided for connecting the roll neck end 18to a driving spindle (not shown). I t

Since a relatively strong magnetic field or flux is desirable for influencing the material being rolled, I preferably provide two relatively powerful electromagnets so, as to obtain two co-operating magnetic fields and throu h which the material being worked on or rol f ed passes during the period of roll reduction. l l

Each of these electromagnets has a generally horseshoe-shaped core 20 which maybe solid if direct current is to be used for energizmg the sameand laminated if alternating current is to be used forthis purpose.

Each magnet is provided with a suitable winding 21 adapted to be connected to a source of supply of electric current (not shown). The lower le of each ma et is formed so asto provi e a snug slidin fit with the extended cylindrical end 22 o the lower roll 16. The portions of 'the magnet core or rather the end of thelower leg of each magnet is split as shown at 23 in order that the magnets maybe readily assembled on the extended necks of the lower roll 16.

Since the upper roll is so mounted'as to be capable of jumping or rising above the lower roll 24 of the magnets are provided with side aces 25 which are flat and smooth and are adapted to bear against of the roll necks of the smooth, flat ends 26 upper roll 15. 7

While an appreciable distance-is shown in Fi 1 of the drawings between the ends of the nec ksof roll 15 and the'adjacent faces 25 of the upper legs of the electroma ets, this distance 1n actual ractice is ma e as small as possible and in act a metal to metal contact,

plus the necessary oil film, which is preferably and normally maintained to reduce friction'caused byothe pull of the magnets on the roll necks of th rolls. In practice, the ends when materia enters the pass between the rolls, the upper le vlsse'cured at its forwar of the magnets are 'preferablly water cooled whereby no appreciable heat is transferred 7 from magnet torolls or viceversa.

Each magnet is referably. mounted in place by means of a aterally extending support foot 27, a support base 28 and a roller ulcrum 29. Such a structure minimizes the slidin friction between the bore of the lower legs 0 the magnets and the extended necks 22 of lower roll16; the osition of 'laterall extending support foot 2 being chosen with this 'end in v ew.

Lifting eyes 30 are preferably provided whereby the magnets may be readily'transported from place to place and located in operative position with relation to the reducing rolls.

The roll necks, as is now common, are preferably furnished with an adequate sup ly of water through pipes 31 controlled by valves 32.

The mechanisms more or less diagrammatically disclosed in'Fig. 5 are adapted to permit magnetic material to be fed throu h the roll pass and to scrape from the rol s any material which may adhere thereto.

The material being reduced bythe'rolls 15 and 16 is marked 33 and in the set-up illustrated in Figs. 1 and 2, the ma 'netic field or flux lines created by the two e are indicated by the arrows. It will beseen that when the ma'gnets'are arranged as in Figs. 1 and 2, the magneticlines pass per nectromagnets cally, "i ustrated. mechanisms for idingi rofil s of a material 'to and from the reducing mill. Such mechanismswith suitable modifications can be used for either a two-high finishing mill or'a strip mill of'either the '14s in ig. 5, Imayemply'a frame 34, which supports a. fore table 35 made of nonmagnetlc material and a cover 36 preferably two, threg or four high variety.

upwardly c'urved its entrance side. as at 3 cover are preferably pro- The table and vided with scrapers 38" and 39 yieldingly held in contact with the u reducing rolls respectively, y some means, such as springs 40 and 41. Cover 36 is prefper and lower erably provided with a to member 42 which cover 36 and adjacent its -rear end rests on anupwardextension 44 of frame 34.

At the outlet side of the rolls,

strippers

45 and 46 are employed and these P ably formed with angled'arms, as shown in Figure 5', whereby they are yieldin lyheld in contact with the rolls b means of

springs

47 and 48. The material lining the

rolls

15 and 16 passes between non-magnetic members49and50.

endas at 43 'to are prefer The material being rolled is designated 33 terial. Themechani first to feed the ma reducing rolls and to around the rolls during the roll reductio ducing rolls stripp (1 particles of in material from Member 49 is pr guide member 51.

51 are useful in conne finishing mill or by me they serv roll in p of the mi ing tion applie dem such as employe \Vhen my inve nection with two s the magnetic field ing its red the grain of the mate nally of the piece as Fig. 3, for example.

this form of connect the lamina cessive pairs of r said cores with sui way, the magnetic field ins the piece acr grain as in F assuming that th the direction of the arrow magnetic field gitudinally and pa ll and upwardly to the piece rearwa behind and thence dow again. Above the piece, the core, into the upper r piece, along the piece re behind and thence upw roll 54. In both Figs. represent the direction of th case oftandem mill means for the cores are of the core piece able holes 57 wh necks 58. The equiva ro along be maintained between the supporting fra netic bearings or br stood.

In Fig. 6, I hav of the princi 60 plication tion with a forge,

in connec suitable piece of be the practice, f it is preferably netic base 61 and intermediate its frameoccurs and then mechanically working said Guide members e to guide the d to two stands set-up in the ma notion is disposed alon rial, that is, is clearly in ls 53 and 5 table windings oss or perpen rain in the longitudi 35 held through th through the core traverses th sses into the s may be provi ich suitably rece orm or use of. the .appar sins of Fig. 5 are adapted work a suitable core 62 is interposed which terial to and from the is provided with windi-ngs'68 1n the usual revent it from curlway and as will be understood from the foreue to ma netic pull going. 64 represents the material being op- 11, next, to eep the reerated upon and as indicated by the arrows from adhering the magnetic field passes along the core into and next to strip the the framework of the machine, downwardly the rolls as is now common. thereafter and through the material being ovided with an inclined operated upon and then back through the 42 and framework tov thecore by the shortest and ction with a two-high easiest path as is characteristic of magnetic hen operated by hand fields. i mechanical manipulator as While my invention is particularly apmaterial overthe top plicable to the finishing of sheet, plate or the catcher side strip material, it will be apparent that it Her side of the mill.

have shown my invenbars, tubes, wire and the like.

arranged in tan- It is not necessary that the method of my inuous rolling. invention be utilized in the standard mill mployed in conpractice of finishing sheets, strips or plates, tands arranged in tandem, but if desired, finished sheets, strips or plates ter1aldl 1rmay be treated in accordance with this ing or w1t h vention and in the case of finished sheets, it longitudiis vpreferable to apply the method to two, dlcated In three or four sheets. These may be placed may also be utilized in the finishing of rods,

as in a pack, raised to the proper temperae invention, I suitably ture and then given one or more passes withted or solid cores 52 t0 P in the magnetic field. The reduction made 4 and provld on the finished sheets may be only slight, if

55. In thl desired. d of traversing I find that in some cases a material addlclllally t0 the vantage is obtained evenif the material beows along the mg treated is not raised to atemperature nally Set-u]? mag above the critical range for such material. bove the ple e 3 and In fact, the material may be treated cold or -Conseq1 1en 1y, at room temperature or above. In some e materlal 1S tra ng 111 cases, the reduction made in the pass or (Fig. 3) h lower passes whereinthe material is subjected to '6 lower Core 1011- the magnetic flux, may be as slight as 1% or forward lower f 1% t 3%. lec and thence I find that advantages are obtained where h lower You the material is stretched as by means of a n the core stretcherv leveler during the time it is subth fie d P e along jected to the action of magnetic field.

dOWIl Into the Due to the tendency of the reducing rolls y t0 the You to move one toward the other under the iny Into the pp fluence of the magnetic pull, the mill hous- 3 n 4 the arrows ings are relieved of a material amount of e field- In strain and the spring of the rolls is materials no special supporting 1 l d; h ehfis I believe that I will be able to maintain fi Wlth sulta much flatter pass than has been possible W the You heretofore and for this reason, I believe that lent Of an hig P may magnetic sheets rolled in accordance with t roll necks a this invention will be much more uniform as k 59 e to magnetic and electricalproperties than asses 60 as wlll be underh t h t f d,

Having thus described my invention, what 6 Ill a fhFther {*P' I claim as new and desire to secure by Letples of my lllvehtloh ters Patent is P other 1. A method of improving characteristics Whatever may of a metallic material, which consists in heat- 7 etlls ing the material to a temperature above that supported on h n nm gat which molecular rearrangement therein I ment therein occurs'and then prior to rearrangement in subjecting said material to pressure suflicient to change the cross section thereof and while subjected to such pressure in subjecting said material to the influence of a magnetic flux of suflicient intensity to contribute to improvement of the material.

3. A method of improving the magnetic characteristics of metallic sheeted material, which consists in heating the material to a temperature above that at which molecular rearrangement occurs within the material, then in reducing the gauge of the sheeted material at about the time such molecular rearrangement occurs and during such reduction in gauge in subjecting the material to the influence of a magnetic flux of suflicient intensity to beneficially influence the magnetic characteristics.

4. A method of obtaining desired characteristics in silicon steel sheets which consists in carrying on the final reduction at that temperature where molecular rearrangement within the material occurs and during such reduction in subjecting the material to the influence of a magnetic flux of suflicient intensity to beneficially influence the magnetic characteristics.

5. A method of finishing ma etic sheets which consists in completing t e final mechanical reduction of a pack at a temperature not lower than the ordinary re-heating temperature, and while making such reduction in subjecting the pack to the influence of a relatively strong magnetic flux.

6. A method of finishing magnetic sheets which consists in completmg the final mechanical reduction of a pack at a temperature not lowerthan the ordinary re-heating temperature, and while making such reduction in causing a magnetic flux of'relatively great intensity to traverse the pack on lines perpendicular thereto.

7. A method of beneficially affecting the grain structure of ferrous material reduced to form by rolling or other forging which consists in heating the material to be rolled or forged to a temperature above that at which molecular rearrangement within the material occurs, in subjecting the heated material to the influence of a traversing'magnetic flux of relativel great intensity and in performing the rolling or forging prior to and during the time the material drops below the temperature of molecular rearrangement and while the same is under the influence of said magnetic flux.

8. A method of improving characteristics of a metallic material, which consists in mechanically working said material while at about the temperature at which molecular rearrangement therein occurs and while so working in subjecting said material to the influence of a magnetic field of such intensity as to contribute to such improvement.

9. A method of improving the magnetic properties of a metallic material, which consists in subjecting said material to pressure suflicient to change its cross sectional area.

while said material is at about the temperature at which molecular rearrangement takes place and while such material is subjected to the influence of a magnetic flux of'suflicient intensity to influence the molecular rearrangement. a

10. A method of improving characteristics of a metallic material, which consists in heating the material to rolling temperature, in mechanically working the material and in subjecting the same to the influence of a magnetic field of such intensity as to contribute to such improvement.

11. A method of improving the magnetic properties of a metallic material, which consists in heating the material to rolling tem-- perature, then in subjecting said material to pressure sufficient to change the cross section thereof and while subjected to such pressure in subjecting said material to the influence of a magnetic flux of suificient intensity to contribute to improvement of the material.

12. A method of improving the magnetic characteristics of metallic sheeted material, which consists in heating the material to rolling temperature, then in reducing the gauge of the sheeted material and during such reduction in gauge in subjecting the material to the influence of a magnetic flux of suflicient intensity to beneficially influence the magnetic characteristics.

13. A method of obtaining desired characteristics in silicon steel sheets which "con-. sists in carrying on the final hot reduction within the influence of a magnetic flux of sufficient intensity to beneficially influence the magnetic characteristics.

14. A method of finishing magnetic sheets which consists in completing the final mechanical reduction of a pack while the same is subjected to the influence of a relatively strong magnetic flux.

15. A method of finishing magnetic sheets which consists in completing the final mechanical reduction within a magnetic flux of relatively great intensity and traversing the pack on lines perpendicular thereto.

16. A method of improving characteristics of a metallic material, which consists in mea temperature within chanically working said material while hot and while so working in subjecting the same to the influence of a magnetic field of such intensity as to contribute to such improvement.

17 The method of producing changes in metallic'materials that enhance the proper ties thereof, that comprises mechanically working the material while hot and being subjected to magnetizing forces of such intensity as to permeate the same with magnetic lines of force.

18. The method of producin changes in metallic materials that make or improvement in the general properties thereof and pronounced improvement in certain specific properties that comp rises mechanically working the material while hot and being subjected to magnetizing forces.

19. The method of producing changes in metallic materials that enhances the properties thereof, that comprises mechanically working the material, as by rolling 0r forging, while hot and being subjected to magnetizing forces.

20. The method of producing changes in metallic material that make for improvement in the quality of its properties that comprises mechanically working the material, as by rolling or forging, and applying magnetizing forces to .the material in such manner as to permeate the material with magnetic lines of force at the points where the mechanical forces are applied.

21. The method of improving the physical and/or magnetic properties of metallic materials that comprises heating the material to a temperature such that the material will take a predetermined amount of'elongation, placing the material within a magnetic field, and elongating the material while in said field.-

22. The method of improvin the physical and/or magnetic properties 0 metallic materials that comprises heating the material to the range at which molecular rearrangement occurs, placing the material in a magnetic field, and mechanically stressing the material while in said field.

23. The method of improving the physical and/or magnetic properties of metallic ma-.

terials that comprises heating the material to a temperature above that at which molecular rearrangement occurs, placing the material within a magnetic field and stressing the material beyon the yield point 24. The method of improving the physical and/or magnetic properties of paramagnetic materials that comprises heating the material to a temperature within the range defined by the decalescent and recalescent points of the material, mechanically stressing the material while within said temperature range to produce a permanent set therein, and magnetizing the material in a direction normal to the direction of stress.

i 25. The method of improving the physical thereof. I

and/or magnetic properties of metallic materials that comprises deforming the material by mechanically stressing the material, and subjecting the material to the action of a magnetic field while under stress.

26. The method of improving the physical and/or magnetic properties of metallic ma: terials that comprises heating the material, placing the material within a magnetic field, and elongating the heated material while in said field.

27. The method of improving the physical and/or magnetic properties of metallic materials that consists in producing beneficial rearrangement of the molecular structure of the material by subjecting the material to the action of mechanical and magnetizing forces of suflicient magnitude to effect such rearrangement.

28. The method of improvingthe physical and/or magnetic properties of paramagnetic materials that comprises heating the material to a temperature within the range defined by the decalescent and recalescent points of the material, mechanically stressing the material while within said temperature range to produce a permanent set therein, magnetizing the material in a direction normal to the direction of stress, and allowing the material to cool while being so stressed and magnetized.

29. The method of producing electrical sheets each having substantially the same watt loss, per unit of weight, resulting from varying and /or periodic magnetizing forces, that comprises hot rolling a starting piece through the usual number of reducing and finishing passes, cutting the rolled material into strips or sheets, placing the sheets in a magnetic field and stressing to the point of producing a permanent set therein while in said field.

sheets each having substantially the same watt loss, per unit of weight, resulting from varying and/or periodic magnetizing forces, that comprises hot rolling a starting piece through the usual number of reducing and finishing passes, cutting'the rolled material into strips or sheets, placin the sheets in a magnetic field and stressin said sheets geygnd the yield point thereo while in said 31. The method of producing electrical sheets each having substantially the same watt loss, per unit of weight, resulting from varying and/or periodic magnetizing forces, that comprises hot rolling a starting piece through the usual number of reducing and finishin passes, cutting the rolled material into strips or sheets, heating said sheets to a temperature above that at which decalescence occurs, placing said sheets in a ma netic field, and then mechanically stressing t e sheets to or beyond the yield point.

32. The method of producing electrical sheets each having substantially the same watt loss, per unit of weight, resulting from varying and/or periodic magnetizing forces, that comprises hot rolling a starting piece through the usual number of reducing and finishing passes, cutting the rolled material into strips or sheets, heating said sheets to a temperature above that at which decalescence occurs, placing said sheets in a magnetic field and stressing said sheets in tension sufficient to produce elongation therein.

In testimony whereof, I have hereunto subscribed my name this 8th da of Jul 1932.

' OTH M. O'lTE.