US1978222A - Method of and apparatus for treating metallic materials - Google Patents

Description

Oct. 23, 1934. o. M. OTTE METHOD OF AND APPARATUS FOR TREATING METALLIC MATERIAL-s I l l I I I I I I l I l I I I I I I I I I 2 Sheets-Sheet l I I I I I I I 77ZINVENTOR Wfi/WWM Oct. 23, 1934. o OTTE 1,978,222

METHOD OF AND APPARATUS FOR TREATING METALLIC MATERIALS Filed Sept. 24, 1952 2 Sheets-Sheet 2 Patented Oct. 23, 1934 UNITED STATES PATENT OFFICE METHOD OF AND APPARATUS FOR TREAT- ING METALLIGI! IWIATERIALS Pennsylvania Application September 24, 1932, Serial No. 634,713 1 9 Claims. (Cl. 175-21) This invention relates to methods of and apparatus for producing metallic materials, starting with the pouring of the metal in its molten state and concluding with the finished product which of course may take various forms.

The invention may be practiced on metal in general, whether diamagnetic or paramagnetic, and in particular on metals such as iron, steel, or the ferrous alloys where it is desired that the finished product shall have uniform and im-- proved physical and/or magnetic properties.

In the manufacture of metallic products such as are rolled from ingots, the ingots are formed by pouring molten metal from ladies into moulds. Most ladies in general use, are provided with tapholes in the bottom thereof so that in the pouring operation, the ladle is positioned with ingot when solidification takes place. These oxides are detrimental and impair the quality of the ingots.

An object of this invention is the provision of a method of forming ingots that shall be substantially free of impregnated oxides.

Another object of the invention is the provision of a method of treating a molten mass of metal to improve the molecular structure and the arrangement and formation of the crystals 40 in the solidified mass.

A further object of the invention is the provision of a method of producing ingots or the like so as to impart properties thereto that shall result in improved physical and/or magnetic properties in articles of manufacture made therefrom.

A still further object of the invention is the provision of a metallic mass, such as an ingot, having improved grain and molecular structure, from which metallic articles, for example, electrical sheets and core materials, may be made, the formation and arrangement of the grain and molecular structure of the ingot having much to do with the physical and/or magnetic properties of these products.

In the prior art, it was the usual practice in the pouring of ingots to let the metal cool inthe moulds until it was solidified and frozen, after which the moulds were stripped from the metal and the ingots placed in soaking pits where they could take on heat over a long period of time, causing the entire ingot to be heated to a uniform temperature throughout. When so forming an ingot, the arrangement of the molecules and'the crystals was more or less of a random nature.

In order to impart physical and/or magnetic properties which were desired in a given product made from such ingots, it was the practice to roll the ingot into bars or sheets. These bars or sheets were then rolled or worked, either hot or cold into their final form and in some cases heat treated depending upon the physical and/ or magnetic properties desired in the finished product. Thus, in the prior art, aside from the analysis of the ingot, the ultimate physical properties sought in the finished product were attained by working or rolling, either hot or cold, coupled with various kinds of heat treatment.

In the production of electrical sheets, it has been the practice to start with an ingot of a given analysis and to roll the ingot, through one or more passes, into break-downs, suitable for pack rolling. Such sheets were given heat treatment between the various passes or at least between some of the passes, and after giving the final pass or passes to a pack, it has been customary to anneal the sheets at a predetermined temperature.

It has been found by observation and experience that electrical sheets produced under these conditions will vary widely in their physical and/or magnetic properties, and that even in the case of sheets taken from the same pack. wide variations have been found between different sheets of the pack, bothin respect to the physical and or magnetic properties thereof. It is also quite common to find portions of areas of the same sheet which vary widely in the magnetic properties, such as the watt loss and permeability.

Based on observation and experiment, I have drawn the conclusion, and it is my belief, that metallic materials when worked either hot or cold, undergo fundamental changes which have much to do with the physical and or magnetic properties of the material. It is my belief also that different portions or areas of material undergoing working or rolling offer greater resistance to the occurrence of these fundamental changes than other portions, with the result that wide variations in the physical and/or magnetic properties result.

One of the causes for these variations may be traced to the formation of the ingot, that is, it is my belief that the molecular system and the crystal formation of the ingot as made in the prior art are not orderly and regular, either in size or directional arrangement.

Thus, if in the formation of the ingot the molecular system be placed under the influence of forces other than heat and pressure that will cause orderly arrangement of the molecular sys-' tem and directional arrangement of the crystal formation, it is my belief that finished metallic articles produced from such ingots will have far superior properties, both in respect to the physical and the magnetic or electrical properties, than it has heretofore been possible to attain in similar products made in accordance with prior art methods.

It is therefore an object of the invention to provide a method whereby molecular arrangement and the crystal formation in ingots may be so controlled that when solidification of the ingot occurs, the molecular structure and the crystal formation will in the production of metallic products, greatly improve the physical and/or magnetic properties thereof.

Other objects f the invention will, in part, be apparent an will, in part, be obvious from the following description taken in conjunction with the accompanying drawings, in which:

Figure l is a pictorial view illustrating the pouring of molten metal into moulds having inert gas supplied thereto for preventing oxidization of the metal;

Fig. 2 is a top plan view of a series of moulds and apparatus adapted to carry out the method embodying the invention;

Fig. 3 is an enlarged view in section of the apparatus shown in Fig. 2, taken on lines III--III thereof; and

Fig. 4 is a fragmentary view partly in section, of one of the moulds and a part of the apparatus illustrated in Fig. 3.

Throughout the drawings and the specification, like reference characters indicate like parts.

Generally stated, the method embodying the invention includes the pouring of molten metal from a ladle into a mould and, while the metal is molten, the passage of electric current, either alternating or direct, through the metal. In a preferred form of the invention it is proposed to introduce a medium, such as a non-explosive inert gas adapted to prevent oxidization of metal, into the moulds prior to pouring of the metal and to introduce such medium into the bottom of the mould. Thus, when the molten metal strikes the bottom of the mould, the inert gas being heated to a high temperature, expands many times its original volume so as to envelop the stream of metal pouring into the mould. It is also proposed to continue the supply of such medium to the mould until the pouring operation is complete. When the mould has been poured, the mould may be capped to exclude oxidizing agents therefrom such as atmospheric air.

By pouring the ingots in a non-oxidizing atmosphere, the ingots when solidified will be free, or substantially so, of impregnated oxides.

While the metal is molten and at a temperature above that at which solidification commences, the molecular system is relatively free to move and easily affected by such agencies as electric current. By passing electric current of sufllcient density to impart or induce orderly arrangement of the molecular system, this arrangement will become more or less fixed when the metal approaches the solidification stage.

If the flow of electric current through the molten mass be maintained continuously without interruption as the temperature of the mass drops, the resistance thereof to current flow decreases, permitting an electric current of greater intensity to flow, thus providing increased electrical energy for molecular alinement. This increase in electrical energy partially compensates for the reduced freedom of molecular motion, in the cooling mass.

As the temperature of the molten mass continues to fall toward the temperature at which the first stages of crystallization and segregation occur, the electric current has sufficiently influenced molecular arrangement and structure so as to cause orientation of the crystals. The electric currents tend to induce directional arrangement of the crystal axes with the axes disposed in the same general direction as the current flows through the molten mass.

As solidification commences, for example, at temperatures around 2650 F. for the iron silicon alloys, the freedom of molecular movement is materially diminished which phenomenon is manifest by an evolution of heat. Therefore, greater energy is necessary to accomplish further rearrangement of the molecular structure as the metallic nass drops to temperatures below the freezing temperature. ance of the mass decreases with decreasing temperature, the current fiow is increased so that greater or increased energy is applied to the molecular system to effect the beneficial rearrangement referred to above.

When the temperature of the cooling mass is approaching the temperature at which it begins to manifest attraction for a magnet, and preferably at a temperature well above this critical temperature, I propose to subject the mass to magnetizing forces sufllcient to permeate the same with lines of force, thereby increasing the energy required to promote the occurrence of these fundamental changes. It is preferred to so arrange magnetizing forces that the magnetic lines of force will permeate the metallic mass in substantially the same direction as the current flows therethrough.

The magnetic critical temperature range of metal varies with the particular analysis thereof. For example, iron silicon alloys containing about 4% silicon become non-magnetic at a temperature of approximately 1460" F. Between 1460 F. and approximately 1200 F. such alloys are increasingly magnetic, but the permeability is somewhat less than obtained when the temperature is below 1200 F. Thus in this application the critical range is to be understood as that range in which the permeability is materially less than at a temperature below the lower limit of the range and which material is substantially or completely non-magnetic above the upper temperature of the range.

In accordance with this method, I propose to subject the mass to magnetizing forces at a temperature above the critical range and to maintain such forces in action on the mass as it cools down through the magnetic critical range and below.

The flow of current and magnetizing forces may be maintained in active association with the metallic mass throughout the entire process, or the flow of current may be interrupted either Since the ohmic resistslightly before the magnetizing forces are applied or slightly after. The intensity of the current and the magnetizing forces may be varied throughout the entire process or may be held constant depending upon the ultimate structure and properties desired in'the finished product.

The magnetizing forces and the electric current through the mass may also be continued until the ingot has cooled to a temperature at which there is substantial stability in the molecular system.

After the ingot has cooled as above described, the mould is stripped therefrom and the ingot placed in a soaking pit, which is maintained at a predetermined temperature, until the entire ingot is at a uniform temperature throughout. When the ingot is in such condition it may be rolled into breakdowns in accordance with standard mill practice.

If the ingot is adapted or intended to be manufactured into electrical sheets, the practice is to roll the ingot into breakdowns suitable for pack rolling. When the breakdowns have been rolled and folded to form a pack, the finished rolled pack may be given an annealing treatment at a temperature which will further improve the physical and/or magnetic properties thereof.

In order to further improve the magnetic and/or physical properties of the material, especially in the case of electrical sheets, I propose to roll the metal in a magnetic field as disclosed in United States Patent No. 1,909,887, granted May 16, 1933.

For a clear understanding of the invention reference may be had to the drawings in which the method embodying the invention is pictorially illustrated from the pouring stage to and through the solidification stage.

With reference to Figure 1 a plurality of moulds 1 are shown into which molten metal is poured from a ladle 2 having a taphole in the bottom thereof as indicated by the stream 3 of molten metal discharging therefrom.

In pouring these moulds it may be assumed that the pouring is started with the mould farthest to the right as seen in Fig. 1. Prior to pouring it is preferred to introduce a medium into the bottom of the mould which serves to prevent oxidation of the molten metal. It is preferred to utilize an inert gas such as nitrogen. In order that the gas may be introduced into the bottom of the mould, a pipe 4 having a long nozzle 5 is provided, the pipe being connected to a supply line 6 leading to a source of supply of nitrogen gas, not shown. The relatively long nozzle 5 extends downwardly into the mould as shown in Fig. 1 so that the gas initially-introduced will be delivered to the bottom of the mould. After the initial charge of gas has been introduced nto the mould the long nozzled pipe is withdrawn and a pipe 7 having a short nozzle 8 is hung over the upper edge or the top of the mould.

When the molten metal is first poured into the mould it strikes the bottom thereof vigorously and because of its exceedingly high temperature, the initial charge of inert gas in the bottom of the mould is quickly heated to a high temperature causing it to expand many times its initial volume. As the gas expands it rises and envelops the stream of metal entering the mould. While the pouring is in progress inert gas is introduced through the short nozzled pipe '7 until the mould is milled with metal. The moulds may be poured in this manner one after another.

As each mould is filled it is capped by means of a cap 9, so as to exclude, as far as possible, oxidizing agents such as atmospheric air.

While the metal is still molten in the mould and at a temperature above that at which solidification substantially the same general direction asthe current was flowing through the mass.

As solidification takes place, which is at a temperature of approximately 2650 .F. for the iron silicon alloys, freedom of molecular movement is greatly diminished, such being manifest by evolution of heat. I

When the mass of metal is at a temperature below freezing, greater force is required to effect" the occurrence of fundamental changes and structural molecular rearrangement. When freezing occurs, the current flowing through the mass of metal is increased, as stated above, thereby increasing the force. Below this point it is proposed to subject the mass to magnetizing forces in addition to the force exerted by the current flowing through the metal. It is preferred to so arrange the magnetizing forces that they shall permeate the metal in a direction parallel to or linearly with the flow of current. By varying the intensity of the current and the intensity of the magnetizing forces either separately or jointly, the qualt-ity of the desired properties of the metal, as manifest in the finished product, may be greatly influenced.

It is preferred to apply the magnetizing forces to the metal before it has cooled to a temperature within the critical magnetic range of the particular metal under treatment.

It is preferred to maintain the magnetizing forces applied continuously to the mass while and as it cools from above the critical magnetic range to a temperature of say, below 1260 F. or lower. The current may also be passed continuously through the mass as it cools down through the critical magnetic range and to or below the temperature above mentioned. If the density of the current is sufliciently high, the cooling period may be delayed or prolonged which will beneficially improve the quality of the ingot.

It is my belief, based on experiment and experience, that the passage of current through the mass while molten and as it cools, has a tendency to increasethe length of the crystals in the direction of the flow of current and to accentuate growth thereof, and the effect of the magnetizing forces and the flux permeating the mass is to accentuate crystal growth and molecular rearrangement. Thus, while the metal is molten, an orderly distribution and arrangement of the molecules is induced and becomes fixed when the metal freezes.

Alternating current, as stated above, may also i be utilized which when flowing through the molten metal causes agitation and orderly arrangement of the molecular structure. Such current tends also to drive out foreign occluded substances such as gases.

The means for passing current through the molten mass and for subjecting the mass to magnetizing forces are illustrated more particularly in Fig. 3. As shown in Fig. 3, means are provided for treating rows of mouldshaving molten metal therein. The moulds of this type are placed on base plates 11 which are in turn carried on partition walls 12 and 13 arranged to form a series of rectangular pits 14. The walls, as indicated,

are preferably made of a material such as concrete. The base plates 11 have apertures 15 through which metallic plugs 16 of magnetic material may protrude. These plugs are supported on housings 17 of substantially U-shape in section, but insulated therefrom by means of insulation 18. Plugs 16 are insulated from base plates 11 by means of insulation 19 and the space between the plugs and the bases is filled with a refractory clay 20 to prevent molten metal from flowing into the pits and on the metal housings 17.

In order to prevent plugs 16 from freezing to the ingots, metal caps C are provided. The edges of these caps extend into the clay 20 and effectively seal plugs 16 from the metal in the moulds. When the moulds are raised from the base plates, the caps being frozen to the ingots, are pulled away from the plugs 16.

Each plug 16 is connected by a conductor 21 which is insulated, to a plurality of conductors 22 which in turn are connected to a series of bus bars 23 of the same polarity. As may be seen in Fig. 4, each conductor 21 is of large cross-sectional area so that it may carry very high current, for example 2000 amperes and upwards.

In order that current may be passed through the molten metal in the moulds 1, a yoke 24 is provided. This yoke is made of magnetic material and of sufiicient cross-sectional area that it may carry the maximum amount of current that may be passed through the metal in the moulds. The yoke terminates in a wedge-like portion 25 adapted to be received in a wedge-type terminal 26 which is connected by conductors 2'? to a plurality of bus bars 28 of the same polarity but of opposite polarity with reference to bus bars 23. Each terminal 26 includes a housing 29 which is stationarily mounted in an aperture formed in a wall 30 of concrete or other suitable material. it being insulated from the wall by means of spacers 31 of insulating material.

Each terminal 26 includes a movable contact block 32 which is backed by a spring 33 disposed about a guide rod 34, this rod, as shown, being threaded into one end of the housing 29.

Each yoke 24 is provided with a lifting eyebolt 35 so that a crane may be employed to mount the yokes in operative relation to terminals 26 and the moulds. The opposite end of each yoke is shaped so that it may extend through an opening or aperture 36 in the mould caps 9 and into the metal. In order to prevent freezing of the portion of yoke 25 that extends into the molten metal, a cap 37 is provided which is pressed over the end of each yoke so that after the ingot has solidified and cooled the cap will be frozen in the metal and thus allow the ingot to be stripped from the yoke when it is lifted away from the mould and out of the associated terminal 25.

In order that magnetizing forces may be applied to the metal as above described, a core 38 is attached to each yoke about which a magnetizing winding or windings 39 is wound. The terminals of the windings are taken upwardly through a conduit 40 and thence to terminals 41 which may be removably connected to terminals 42 and 43 to which direct or alternating current potential may be supplied, depending upon which is best suited to the treatment of the metal. The

lower end of each core 38 is threaded to accommodate a cap 44 adapted to seat on a plug 45 of magnetic material, insulation 46 being interposed between the cap and the plug. Each plug 45 is connected by means of a core 48 of magnetic material to its associated plug 16 so that a magnetic circuit, including plugs 16 and 45, cores 38 and 48, yoke 24 and the metal in the mould, is formed.

Plugs 16 and 45 are preferably made integral with core yoke 48 and may be provided with diametrically opposed lugs L and L' for supporting the yoke and plugs on housing 17. These lugs are insulated from the housing by means of insulation 18. Insulation 18 may be extended into the housing, as indicated in broken lines in Fig. 3, to insulate yoke 48 from the side walls of the housing.

While the metal is molten it does not manifest attraction for a magnet, nevertheless the molecules composing the molten mass will be influenced by the magnetic flux developed in the circuit above mentioned. As the metal solidifies and later becomes permeable, the magnetic lines of force passing through the metal will increase with the permeability in accordance with well known laws. The magnetic lines or flux may, of course, be maintained continuously in the metal as it cools from a temperature well above the critical magnetic range, through the magnetic range down to a temperature at which the molecular structure of the solidified mass is stable.

As is apparent by inspection of Fig. 2, any number of moulds may be treated at the same time by providing a sufllcient number of units of the apparatus required for magnetizing the mass and for passing electric current therethrough. As is apparent by inspection of Figs. 2 and 3 there are two rows of moulds each provided with apparatus for passing current and/ or magnetic lines of force through the metal in the mould.

It is to be understood that the particular apparatus employed for treating the metal in the ingots beginning with the pouring thereof until the metal has frozen into a solid state may be varied without departing either from the spirit or the scope of the invention. It will also be appreciated that the particular form of the apparatus employed for treating the molten metal from its molten state to its solid state may also be varied to suit particular or special methods under consideration.

After the ingots have solidified and cooled down to a temperature preferably below 1260 F., the yokes 24, the cores 38 attached thereto and coils 39 are lifted bodily (as a unit) by means of the eyebolts 35, away from the moulds and the terminals 26. Thus core 38 and terminal 25 of each unit, are disengaged from core plug 45 and terminal 26, respectively, by this operation.

The moulds are then stripped from the ingots after which the ingots may be placed in soaking pits. The purpose of placing the ingots in soaking pits is to cause the ingots to be heated to a predetermined uniform temperature throughout the entire body thereof prior to rolling or working into articles of manufacture.

In treating metal from its molten state, in accordance with this invention, the use of inert gas to prevent oxidation may be omitted where the final product will serve its intended purpose even though the ingot from which it was made contained impregnated oxides.

It is to be understood also, that I may treat the molten metal with current only, or with magnetizing forces only, when either one of these forces acting alone will induce the desired properties in the finished product, and it is to be understood that I do not intend to limit the inventionv to the use of both agencies together as either may give the desired results in certain cases, and to a more or less pronounced degree in all cases.

Since this method lends itself particularly to the production of electrical sheets, the method of producing metallic articles in accordance with this invention will be described from the ingot stage through the various steps which are taken to produce electrical sheets. While the description will be confined to the production of electrical sheets it is to be understood that I do not limit myself to the production of such materials only.

In the rolling of electrical sheets it is desirable to roll the ingots in a direction such as to produce elongation in the direction of the crystal axes, that is in the direction of the grain. Ingots formed in accordance with this method will have the grain disposed in the direction in which the current and the magnetic lines of force are passed through the ingots while in the moulds.

The direction of the current and the magnetic lines of force are indicated by the arrows in Fig. 3. The ingots are rolled into bars of approximately thirty inches in width and about 0.16 inch thick, which bars are cut into pieces approximately thirty inches longand thirty inches wide, the thickness being 0.16 inch thick. These pieces are known as breakdowns in rolling mill parlance.

The breakdowns are rolled to about double their length with the grain as formed in the ingots. These breakdowns are then paired, that is by placing two rolled bars one on the other, and rerolled to further elongate the same. Two such pairs may then be placed one on the other, making four single matched sheets, and reheated in a furnace after which the two pairs are rerolled. After rerolling the matched two pairs, the four sheets are doubled to form a pack comprising eight single sheets. Each pack consisting of eight single sheets, is then reheated and rerolled.

The finish pass may be given to the pack without being reheated. Each of these passes of rolling, starting with the rolling of the ingot, may be effected in a magnetic field as disclosed in United States Patent No. 1,909,887, granted May 16, 1933.

In any case, whether all of the passes are rolled while subjected to the action of a magnetic field, it is to be understood that it is preferred that the rolling be made in such a direction that elongation takes place in the direction of the grain as formed in the original ingot.

While the material may be subjected to a magnetic field during each pass of rolling, it is to be understood that for the sake of economy some of the passes may be rolled without subjecting the material to a magnetic field, particularly in cases where the properties in the finished product need not be of extremely high quality. 7 1

In some cases any two or more of the above mentioned steps of rolling may be combined in a single pass or a combination of passes into a single pass provided the reduced number of operations will give the results desired and produce a product having the desired physicakand/or magnetic properties.

In some cases, it may be sufilcient to subiect the pack to a magnetic field when given the final or finishing pass.- The method of subiecting the material to a magnetic field while being rolled is fully disclosed-in Patent No. 1,909- 887 referred to above.

While a preferred form of the method has been described harem and apparatus illustrated whereby the method may be carried into effect, it is to be understood that the method and the apparatus employed may be varied and modified withous departing either from the spirit or the scope of the invention It is desired, therefore, that only such limitations shall be placed on the invention as are imposed by the prior art and the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. The method of producing metallic material that comprises introducing inert gas into the lower portion of a mould, pouring molten metal into the mould whereby the heat of the metal causes the gas to expand and envelop the metal being poured, passing electric current of relatively high density through the ingot while molten, and subjecting the .ingot to relatively strong magnetizing forces while the ingot freezes and cools to and through its critical temperature range.

2. The method of producing metallic materials that comprises passing electric current through a molten mass of metal, and, as the molten mass commences to freeze, supplementing the action of the current with magnetizing forces of sumcient intensity to permeate the same with magnetic lines of force.

3. The method of producing metallic material that comprises inducing regular and orderly crystal formation in a mass of molten metal by passing electric current through the same until the temperature thereof drops to a value at which the mass is frozen, and then in subjecting the mass to'magnetic lines of force until cool.

4. The method of producing metallic material that comprises pouring molten metal in a mould having an initial charge of inert gas therein, supplying more of such gas while pouring to prevent oxidation of the metal, passing electric current through the molten mass, so as to agitate the molecules and effect uniform directional rearrangement of the crystals and enlargement thereof, until solidification occurs, and thereafter subjecting the frozen mass to magnetizing forces of high intensity acting in substantially the same direction as the current was flowing through the mass.

-5. The method of producing metallic articles of manufacture having improved physical and/ or magnetic properties, that comprises pouring molten metal into a mould having an initial charge of gas therein adapted to prevent oxidation of the metal, supplying more of such gas to the mould and in such quantities as to envelopthe stream of metal entering the same until the pouring is complete, capping the mould to exclude oxidizing agents such as atmospheric air, then while the metal is still molten, passing electric current through the entire mass in the mould, supplementing the action of the current with a magnetic field in which the lines of force permeate the material in the direction of current flow, thereby to induce molecular stability and polarized directional arrangement of the crystals, allowing the metal to cool, while being subjected to said lines of force and current, to a temperature at which substantial molecular stability occurs, stripping the mould from the ingot thus formed and heating the same to relatively high temperature for a period of time sumcient to produce substantially uniform temperature throughout, rolling said ingot in the direction of the grain into strips of predetermined width, cutting the strips into plates or singles of predetermined length,

cross rolling the plates to widen the same, pairing said plates and rolling with the grain to elongate and reduce the same, doubling the rolled pairs to form a pack, annealing the pack at a temperature above the magnetic critical range thereof, then finish rolling the pack in one or more passes and subjecting the material to the action of a magnetic field while being so rolled.

6. The method of producing metallic articles of manufacture having improved physical and/or magnetic properties that comprises pouring molten metal into a mould having an initial charge of gas therein adapted to prevent oxidation of the metal, supplying more of such gas to the mould and in such quantities as to envelop the stream of metal entering the same until the pouring is complete, capping the mould to exclude oxidizing agents such as atmospheric air, then while the metal is still molten, passing electric current through the entire mass in the mould, supplementing the action of the current with a magnetic field in which the lines of force permeate the material in the direction of current flow, thereby to induce molecular stability and polarized directional arrangement of the crystals, allowing the metal to cool, while being subjected to said lines of force and current, to a temperature at which substantial molecular stability occurs, stripping the mould from the ingot thus formed and heating the same to relatively high temperature for a period of time sufllcient to produce substantially uniform temperature throughout, rolling the ingot into breakdowns suitable for pack rolling, forming a pack of said breakdowns, heating the pack to a temperature at which molecular rearrangement occurs and then rolling the pack in a magnetic field.

7. The method of producing metallic articles of manufacture having improved physical and/or magnetic properties that comprises pouring molten metal into a mould having an initial charge of gas therein adapted to prevent oxidation of the metal, supplying more of such gas to the mould and in such quantities as to envelop the stream of metal entering the same until the pouring is complete, capping the mould to exclude oxidizing agents such as atmospheric air, then while the metal is still molten, passing electric current through the entire mass in the mould, supplementing the action of the current with a magnetic field in which the lines of force perass meats the material in the direction of current flow, thereby to induce molecular stability and polarized directional arrangement of the crystals, allowing the metal to cool, while being subjected to said lines of force and current, to a temperature at which substantial molecular stability occurs, stripping the mould from the ingot thus formed and heating the same to relatively high temperature for a period of time sufilcient to produce substantially uniform temperature throughout, rolling the ingot into breakdowns suitable for pack rolling, forming a pack of said breakdowns, heating the pack to a temperature at which molecular rearrangement occurs and then rolling the pack in a magnetic field through one or more passes.

8. The method of producing metallic articles of manufacture having improved physical and/or magnetic properties that comprises pouring molten metal into a mould having an initial charge of gas therein adapted to prevent oxidation of the metal, supplying more of such gas to the mould and in such quantities as to envelop the stream of metal entering the same until the pouring is complete, capping the mould to exclude oxidizing agents such as atmospheric air, then while the metal is still molten, passing electric current through the entire mass in the mould; supplementing the action of the current with a magnetic field in which the lines of force permeate the material in the direction of current flow, thereby to induce molecular arrangement and polarized directional formation of the crystals, allowing the metal to cool, while being subjected to said lines of force and current, to a temperature at which substantial molecular stability occurs, stripping the mould from the ingot thus formed and heating the same to relatively high temperature for a period of time suflicient to produce substantially uniform temperature throughout, rolling the ingot into breakdowns suitable for pack rolling, forming a pack of said breakdowns, heating the pack to a temperature at which molecular rearrangement occurs, then rolling the pack in a direction to produce elongation with the grain and while the pack is being rolled subjecting the same to a magnetic field arranged to permeate the material at the point of rolling pressure.

9. The method of producing metallic material that comprises inducing regular and orderly crystal formation in a mass of molten metal by passing electric current through the same, and, while said mass cools and freezes, supplementing the effect of the electric current by subjecting the metallic mass to strong aperiodic magnetizing forces.

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