US16082A - Improvement in the manufacture of iron and steel - Google Patents

Description

I 4 Sheets-Sheet, 1. H. BES'SEM'ER.

MANUFACTURE OF IRON AND STEEL. No. 16,082. Patented ov. 11, 1856.

4 Sheets-Sheet 2.

H. BESSEMER. MANUFACTURE OF IRON AND STEEL.

No. 16,082. Patented Nov. 11, 1856.

'rz llllllllllzlnll I Il/II/IIIIIIIIIIIIIIIIIIIIIIA 'H. BESSEMER, MANUFACTURE OF IRON AND STEEL.

7 No. 16,082. Patented-Nov. 11, 1856.

4 Sheets- Sheet 3.

. e e eee BESSEM MANU URE OF IRON STEEL. No. 16, 082; Patented Nov. 11, 1856 i I l. KTW

9 Th Wm To (all whom it 771/1, concern,

thereotth'at is to say:

from the blast-furnaces in which the iron ore ,fire brleks or other slow conductor of heat. jV jlgrerif'the chamber or yessel is about filled, I

1. asyme gaseous fluid or matter containing 'inthe iron, and thereby to keep up the re- 1 or No. 2. foundry-iron, to which last-named UNI ED STATES PATENT OFFICE;

HENRY. BESSEMER, OF LONDON, ENGLAND.

Specification f n-min; part 0i Lett rs Patent No. l6,02., dated Novi-mlu-r ll, 1856.

- Be it known that I, 1 "[EXRY Bl&\'.SlL\[l-IR, of Queen Street Place, New Gannon Street, in the city of London, civil engineer, a subject of the Queen of Great Britain, have invented or discovered'new and useful Improvements in' the Manufacture of Malleable or Bar Iron and Steel; and I, the said HnxuY Bnssnnnn, do hereby declare the nature of the said invention and in what manner the same is to be performed to be particularly described and ascertained in and by the following statement Myinvcntion consists in the decarhonization or partial dccarbonization and refinement ot the crude iron which is obtained in a fluid state is usually smelted, or the decarbonization and refinement bf'crude pig-iron or finery iron,

formed."

ypreterence of iron, and lined with bio or. force into and among the fluid metal r'onsfsmall jets of atmospheric air in a 'rgiu a' previously-heated state, or I use (juiceiable of evolving suflicient oxygen to cause the combustion of the carbon containedquired temperature during the process. The size or number of the jets or tuyerepipes by which the air or other gaseous matters are conducted into the molten metal should be proportioned to the quantity of fluid metal operated upon at a time, and may also vary withthe condition or quality of the metal. Thus forged pig or refined plate metal will not require so much oxygen to complete i ts decarbonization and conversion into steel or malleable iron as is required for the conversion of crude iron oft-he qualities known as No. 1

qualities of iron I prefer to use tuyeres hav-,, ing an outlet of about twenty per cent; more in ..area than those which are used for the white qualities of iron. It is, howeve r,.ditlicult to' give a precise or fixed rule for the size of the jets or fuyere-pipes, because the quantityof air passing through them depends so much on the force or pressure of the blast.- The quantity should depend also on the quality of the iron and the heat of the air or other gaseous matters used with the air, or in lieu thereof; but as a guide to the workman, I will give an example which I have found in practice to answer well: \Vhen using foundry-iron or the .qulility known as No. 2, Irun one ton of it into the converting-vessel, in which it rises to a. height of about one foot above the orifices of the tuyere-piries; I then force into the fluid metal atmospheric air, in itsnatural or unheated state, under a pressure of about ten pounds-per square inch, and I employ from six to twelve .tuycre-pipcs for-the distribution of the air, the united area. of the tuyeres being equal to two square inches. Thequa-ntity of blast admitted by this area of inlet will in general be found suflieicnt to efiect the conversion of the crude iron into a malleable condition in about thirty minutes; but should it be preferred to use a mixture of oxygen gas with atmospheric air or steam, or to use steam alone or any other gaseous fluid capable of evolving oxygen in lieu of atmospheric air, then the size of the tuycrepipes should be regulated according to the quantityfof oxygen contained in such gaseous fluids. Any excess of oxygen over that usually contained in at mospheric air will admit of a. diminution of the tnyere-pipcs, while a deficiency of oxygen will render-necessary a corresponding increase in the size of the tuyeres.

The interior of the vessel may in some cases be' heated by the waste gases of the blastfur nace or byany other convenientmeans, pre vious to the crude iron being poured or run therein; but this heating up of the vessel wifl only be necessary I at such times as the yessel is used witha newlining, which should be well dried, or at such' other times as the vessel may be used after the process has for "several hours been discontinued, in which case I prefer to reheat the vessel, although the process may be conducted successfully in avessel thatris perfectly cold previous to the running in ofthe molten iron. Now, it is well known that molten crude iron, under or-' dinary.circumstances, will soon become solidiheat of the most. powerfulifurnaces; but 1 have discovered that it atmospheric air 01 oxygen-is thus introduced into the metal in suliicient quantities, it will produce a vivid combustion among the particles of fluid metal, and retain or increase its temperature to such a degree that the metal will continue fluid during its' transition from the state of crude iron to that of cast-steel or malleable iron without the application ofan y fuel; the requisite high temperature of the metal by such mode of action being obtained by the oxygen uniting with and causinga combustion of the carbon contained in the crude iron, and also by the combustion of a smallportion of the iron itself. In carrying my invention into practical operation, I prefer to mount the refining vessel or chamber on axes not situated at or near the center of gravity of the said. chamber, by which means the pouring out of its contents will be facilitated, and the spout kept in a proper position in reference to the mold during the time of pouring the fluidmetal therein. The air may be introduced at the sides or ends of the vessel through small holes formed in pieces of well-burned fire-clay, so

, that by moving the chamber or vessel on its axes the-holes in the fire-clay may be made to descend beneath the surface of the metal or be raised above it, as desired It must be ob served that the air or other gaseous matters must be compressed with a force greater than will balance the weight of a column of fluid metal of a height equal to the depth of im-.

mersion of the jets below the surface of the fluid metal.

In order that this particular form of apparatus may be fully understood, I have hereunto annexed a sheet of drawings (marked A) on which the same is represented, Figure 1 being an end elevation thereof; 111g. 2, a longitudinal elevation, and Fig. 3 a-longitudinal section, of the vessel or chamber; and Figs. 4., 5,

and 6 are crosssect-ious of the same in different positions. The tuyere-pipesare also shown in detail on alarger scale at Figs. 7, 8, 9,- 10, 11, and 12. The cylindrical vessel ais formed.

' of stout vplatc iron, secured by angle-iron They are bored out truly, and fitted and'keyed to the axes b and b, on which the converting: vessel a is made to move when required. 0 c are iron frames, secured by bolts d to the ma sonry or foundation on which the whole apparatus rests. The frame 0' rises higher than the others, and has plummer-blocks eebolted to it, in which the'shaftf revolves. Awormwheel, 1 is keyed firmly onto the axis 1; and receives motion from the worm it whenever the handle i and shaft'f are moved round.

''The interior of the vessel a is lined with-firelining is exposed when thevessel is in use.

Thcbricks or fire stone may, however, be protected and mended or patched from time to time by a coating of loam, road drift, iron-ore slugs, orsueh other matters as are commonly employed for mending and protecting the walls of furnaces used in the manufacture of iron. The lining may be renewed from time to time, when worn out, by removing either of the end plates, (1', which may again be bolted onto the vessel as soon as the new lining is completed; or a man-hole (not shown in the drawings) maybe made in one side of the vessel,through which the lining or. repairs may be effected without removing-the end of the vessel. At a there is formeda projectingspout or lip for the purpose ofrunning outthe fluid metal. This lip is made to project from the vessel so far as to bring itirra line with the axis, so that into whatever position the vessel or may be moved the extremity of the lip u may retain the same position or nearly so, and thus allow the stream of metal flowing over it to fall into the ingot-n1old, vhich would not be the caseif the axis were placed in a. line with the center of the cylindrical vessel. By reference to Fig. 6 it will be seen that at m the lining is formed so as to prevent the metal from carrying out withit the slags .or other matters floating on its surface until.after the metal has run out.

On-each side .of the spout a there isaca passage, 1), by means of which the flame and gaseous products evolved during the process may escape, but the splashes of metal thrown up by the jets of air are for the most partprevented from escaping from the vessel by't he serpentine form of these outlets.

At 1' there is a pipe which is made to com-- municate with a blast-engine or with a steam= boiler; or it may be made to communicate with V a reservoir containing oxygen gas, 'or a mixture of oxygen with other gaseous fluids, or

with any gaseous matter eapableof evolving. oxygen, any or all of which gaseous fluids may be used for'the purpose of my invention,either in a cold or heated state. althoughl prefer to use atmospheric air at its natural temperature on account of its cheapness and efficiency. The pipe 1- is fitted at one end to the trunnion or axis b, which is made hollow, and is provided with a stuffing'box or other joint, so as to allow the movement of the axis,withou't in terfering with the passage of the air or other matters through it. The pipe 8 is also con nected to the hollow-axis b, and has a rightangled elbow or bend at its opposite end, and then continues along the outside of the.vessel throughout its whole length. That portion of the pipe is marked 8*, and is turned truly on its exterior surface, and has fitted upon it several small'branch pipes, u, each of which has a T- ,:piece, at, connected to them, which. is boredout truly, and madeto 'fit accurately to the exterior of the pipe 8*. so as to admit of the pipe a'being" moved on the pipe s* into the position shown by dots in Fig. 5. Along one side of the converting-vessel there is a row of square holes, into which small blocks 7/ of Well-burned fire-clay are loosely fitted. They are held in position by ramming a little loam well into the joint formed between them and the lining m. At one end of these blocks or tuyeres the pipe at is fitted by a simple conejoint. The other ends of the tuyere-blocks have several small holes made in them leading into one larger passage which communicates with the pipe 10, so that a communication .is thus established between numerous points of the interior surface. of the converting-vessel and the blast-engine or reservoir of gaseous matters before referred to, and by means of which numerous small jets or currents of air or other gaseous fluids may be forced into the converting-vessel when required, asluice-cock on the pipe r-(not shown in the drawings) enabling the workman to turn off the supply of air when required; In order that the way in which the pipes and the pipes u are arranged may be better undeistood, I have shown detached viewsof them at Figs. 7 and 8. where it will be seen that the pipe 8* has a hole .in it at x, which is pposite the orifice of the pipe u.

' Throughfthis hole the air may pass freely whenthcpipesat occupy their ordinary positions; but whenever any of the tuyere-blocks require renewing the pipe u can be turned up on the oint forinedat its union with the pipe 8*, as own by dots in Fig, 5, and in which positiph the-1191c win the pipe 8* will be closed whilefree access to the tuyere is obtained.

. I have also shown at Fig.9 auend view, and at Fig. 10 a longitudinal se'ction,- ot a tuyereblock, where z '5 show: the small apertures through which the airescapes into the metal,; all of which, inpassages, unite in the larger? one z*, the orifice of which is made conical Iso asto fit the end of the pipes u. I have also found that a single outlet in each tuyere-block' will answer well in practice, as representedin end elevation atFig. 11, and-in longitudinal section at Fig. 12. where a single parallel pas sage, y,-'leads direetfrom the pipe a into the metal, as these passages sometimes get obstructed. I fit a screw-plug. g; at the back of the elbow of the pipe n, which plug may be removed, if required, while the apparatus is l in use, 'and a steel rod introduced at the ap; erture,which shouldbe thrust entirely through the tuyere-block, and any accidental'accumulation of matter will be thus removed. By refereuc'e-toFig. 1 of the annexed dram the point of junction of two of the webs,which verting-vessel. Into this boss a stud may be attached, for the purpose of suspending a counterbalanc'e-weight, .the chain passing over a pulley supported by the roof or other convenient part of the building,so that the vessel a may the worm-wheel gearing before described.

Having thus pointed outthe manner in which the converting-vessel and the apparatus connected therewith is constructed, Iwill proceed to describe in what'manner the conversion of -molten, crude, orfinery iron is to be effected therein.- I'however wish it to be distinctly understood that although I prefer to use the cation'spf the convertingvessel may be used may either be made movable or it may befixed. The apparatus 'should, by preference, be placed near to the discharge-hole of the blast g'ron'is obtained. The interior of the convertng-vessel may be heated by burning gases wood charcoal or coke may be introduced at the passages p, and a blast of air 'turned on -through the tuyeres, by which the combustion of these substances may be kept up. \Vlien the fuel is consumed and the vessel dried, the air or othergaseous matters maystill continue to be forced in duringthe'timethat the crudeiron is runni 11g from the smelting-furnace into the vessel. For this purpose the vessel is put in the crude-iron, and producing thereby a vivid combustion, while the flame and gaseous productsh'esulting therefrom make their escape by the passages '1). If the crude iron is run into the vessel 'at a low heat, or only a littlcabove its fusing temperature, it will be found rapidly to increase in temperature and at the expiration of about fifteen minutes from the time of .com mencing the process large out of the passages 12, accompanied by 'a rush of bright flame. Afterafew minutes duration copious flame still continues to escape by the jugs it will be seen that a boss, 1;,- is formed at are formed on the end plates, 0., of the coufixed, to which a chainortension-rod may be be more easily moved on its axis by means of above apparatus for the purpose of carrying,

out my said invention, other forms or modifiwith more or less advautage, and that the same or remelting furnace from which the crude fluid thereimin amanner well understood; or some. 1

in the position shdwn in Fig. 3}, amovable at numerous points with .the carbon containedfrothy slags will begin to be thrown violentlythis eruption of slugs entirely ceases, but a.

passages 11. The crude metal at this stage of the process has thrown oil the bulk of its purities and in a few minutes more is in the condition of cast-steel. The exact state of the metal may, however, be ascertained by turn ing the handle and shaft f, so as to bring'the vessel on its axis into the position shown in Fig.6, and thereby discharge a-small quantity of metal into an ingot-mold, which should be quickly cooled and examined; and if found to be not suii'iciently decarbonized, the handle should be reversed, the vessel lowered, and the process' be continued until the metal is decarbonized and purified to the desired extent.

lroln five to ten minutes additional blowing is generally found sufficientito bringthe metal from the condition of caststeel to that of soft malleable iron. Whenever it is desired to suspend the operation of blowing for a short period, the vessel should be broughtinto the position shown in Fig. 5,.whereit will be seen that the upper surface of the metal is below the orifice of the tuyeres, so that the forcing iu-of the air-may cease without the tuyeres becoming stopped up with fluid metahwhich would be the case immediately the blast of air is stopped, provided the orifices of the tnyere-blocks were not raised above the surface of the metal in'the manner described. In. making malleable iron from crude pig-iron of No 1 or2 quality, about thirty to thirty-five minutes is required for the whole process; but the exact point to stop the process so as to obtain metal of any degree of. hardness between hard'steel and soft malleable iron will soon be acquired in practice by the workmen, since the color and volume of the flame issuing from the passages 2 varies with the condition of the metahand forms a good guide for'the workman to judge by. Hecan also take a trialdngotiu.

the manner described at any stage of the pro cess,i f necessary. I have found thatsuch an excess of heat isproduced in the process that the metal continues to 'boil even after the blast of air has ceased, and althoughreduced to the condition of malleable iron is still so far above the melting-point of that metal that it is desirable to lower its temperature before casting or pouring it into molds. Forthis purpose I bring the vessel into the position shown in Fig 5. I then stop oh: the supply of air and place a fire-tile over the orifice of the passages p, so as to prevent the heat from escaping too rapidly, arid thus' cooling and solidifying the surface of the metal. In'this way the metal may subside and be gradually lowered in temperature and be brought into, a proper condition for pouring or casting; or, in place thereof, it maybe allowed to cool down and be stirred or worked and taken out of the vessel in masses.

I would here state that 1 am aware that it has before been proposed to subject crude melted iron to the action of streams-of air or steamwhen flowing in a trough from ablastfurnaceor from a refinery-furnace, also when' in pig-beds; and it has been further proposed to apply streams of air and steam when pud-.

dling iron, heated and kept heated in a pud- -dling1urnace; but in all cases heretofore the r V sion ofthe iron into steel or malleable iron by the simple applicationof streams of oxygen applied to such a mass of melted iron; and I mention thesefacts in order the more fullyto ascertain and define the peculiarity of.this my inventiomwhich I declare to consist in'acting on a mass of melted, crude, or cast iron, (when in a suitable vessel,) by streams of oxygen, (contained in atmospheric air or otherwise,) and without-the further consumption of fuel for heating the vessel or the iron, toconvert such fluid crude or cast iron into steel 01' 'mal-' leable iron. During the interval occupied in cooling down the boiling metal the workman should get his ingot-molds, when they are to be nsed, in a position to receive the stillfluid' 'metal. A-convenient way of doing this is to place them in an iron truck mounted on wheels, which may be moved under the spout of the vessel, and pass outunder the arched openings left in the frames 0 cfor that purpose. Ihave not shown a truck with molds in the drawings hereunto annexed, because them'ode'of constructing it and its size and. form maybe varied to suit anyparticular form of ingot or mold that may be used; and which may be easily arranged. by anyintelligent workman. As

soon as the casting of the ingots is completed, the mold should he removed and" thevessel again lowered down into the position shown in Fig. 4, when the blast of air maybe again turned onto the pipesu and s,.and another charge of crude iron be runinto the vessel to be treated in like manner. 'I.he process of decarbonization and 'refinementpf the metal may thus be carried on until the metal is reduced to the condition of hard or soft steel,or to the condition of steel y or soft malleable iron. In either state, the metal so refined may be poured from the vessel br chamber into suitable ingot-molds, for the purpose of into barS,- rods, or plates by the processes already known andpracticed in the manufacture of iron and steel, I would,however, remark that I have found in some casesthat the ingots of metal contain cells 'or cavities. In such cases I subject the ingot at'a welding heat-to the action of a squeeaer, suchasis' used in the shaping of puddle-balls; orI'subject the ingot to repeated blows in a swage or die under a Ipowerful hammer, so that the parts are forcibly squeezed, pressed, or. driven together, and the pores closed and the surfaces united or welded together prior to subjecting such ingots to the rolling-mill or tilt hammer. In carrying into practical operation this part of my said invention,,it will be necessary for the workman to bring up the in got or mass of metal to such a temperature as will soften it sufiiciently to allow the cavities v in its interior to close up and unite, so as to form it into a compact solid body When using a machine of the kind used for squeezing puddle-balls, I prefer to form transverse grooves both on the lower and upper jaws/of the squeezer, as represented at Fig. 1, Sheet 13, of drawings hereunto annexed, which rep:

resent so much of a squeczer as isnecessaryfl to show the peculiarity described, A A' being'- the grooves or hollows, and B an ingot placed bet-ween the jaws. A similar efiect on the ingot is produced by first hammering it in a swage, as shown at'FigsL- 2 and 3, Sheet B,

of the annexed drawings,- where 0 represents the lower portion of -a steam-hammer having a grooved block or swage, D, fitted :to it. A similar block, E, is'secured ato aheavy'mass of metal, F, which forms the bed of the ham- 1 nier: The workman, after having heated the ingot G, will hold it with a pair of tongs in the groove of the lower -block, while the-upperone falls upon'it with such force as the man who works the hammer may consider necessary. By the use of these grooved surfaces or swages the cast ingot of metal-isless liable to be broken than'when hammered be-' tween two parallel flat surfaces, which do not afiord any support to the sides of the ingot.

The workman will move the ingot backward and. forward, and turn it .over on its other side,- and thus work and compress the metal until he judges that it is suificientlysolidified to be suitable for the tilting or rolling mill.

Figs. 4 andh represent a similar arrangement to the foregoing, the shape of the ingot being hexagonal in cross-section, instead ofsquare, as in the former case. A more perfect'support to the sides of a square bar is, however, obtained by using a swage of the form shown at Figs. 6 and 7, in whichasquare or nearly square notch -or groove is formed at H, Fig.6.. -In the lower blocka corresponding raised projection, J, is formed on the upper or hammer block, by means of which thetendency of the sides of the ingot to crush out is toa great extent prevented. -However, it will be found that'in all these shapes or modifications of the swage or forging surface, the metal, although 'consid-' .erably protected from spreading and giving way laterally, is at. liberty to extend itself in the direction of its length, and is, therefore,

liable to be driven out in that direction, and

- thu's escape from much of the force of the blow andalso to become broken. To obviate these disadvantages, I use a die-or cavity in which the metal is placed, so that when an ingot'or "other mass of metal refined, as hereinbeforedescribed in a softer welding state, s putinto the die, it may receive the most powerful blows or pressure without its parts, being broken or scattered about; but it will, on the *contrary, be retained within the said die cell or cavity and become there consolidated and have its pores so closed and united, so as to be in a condition suitable-for the ordinary forgingor rolling process, This efiect may be apparatus,the details of which are not of much importance, provided thatthe dies are so consp'ongy malleable metal; whether iron or steel,

ity that when a plunger or liammer'is forcibly brought in contact with it, it may thereby be prevented from being'dispers'ed or spread out, but will, on the contrary, be so retained in the said die, cell, or cavity that it will, by theforce gether, and the pores closed an'dthe surfaces meansby which this part of my said inven: tlon may be carriedpinto practical operation may be understood, I have shown-on Sheet B theapparatus as is required to render the following description thereof intelligible,-

Fig. 8 represents an elevation'of thedie or cavity, in which the metal is pressed. It consists of a massive ring or hoop, M, made of wrought-iron, with a lining of steel; or it may be made of chillcdxcastiron hooped with wroug"ht=iron. .It has asquare holepassing such away that the hoopM may slideireely up ordown. 0 represents a portion: of the .bed or foundation plate of a steam hammer', to which the anvi1-block.N is secured. The hammer-block P has attached to its. hammer or plunger fitted also to the hoop'M.

At Fig.1 0, a section'of the die' is shown By reference to the drawings it will be seen down freely through holes formed in the bed 0, and by means of which the hoop may be raised or lowered, as required. In using the die under a steam or other"suitably worked hammer, the hoop is raised by a lever attached to the rods S, so as to keep it in the position again lowered and the highly-compressed ingot removed, in order that-the apparatusnnay be made to operate in like manner upon other ingots. The upper ends ofthe ingots are sometimes too unsound to form a perfect bar, in which case I cut or break them off and reproduced by several'ditterent modifications of structed that the ingot or mass of cellular or bego confined within the said'd'ie, cell, or cavthus-brought to act, upon imam its various parts forcibly squeezed, pressed, or driven tounited or welded together. In order that the of the drawings hereunto annexed so *much of throughit whichis parallel,='or nearly so. nto this hole the anvil-block N- is fitted inhaving a block of metal, R, placed within it, ready to receive a blow from'the'hammeni that the hoop M is supported by two guiderods, S, which are bolted to it, and which pass shown in Fig. 10. The heated ingot or mass got be repeated, after which the hoop may be turn such scrap or waste pieces to thedecan .bonizing-chamber at the times! refilling it for another operation; and so, in like manner, other scrap metal resulting from the spilling or splashing of the fluid metal and also the bar or crop ends and ,shearings from the plates or bars of rolled metal may thus be brought into use by remelting them in the fluid metal contained in the converting-vessel without the use of any fuel forthat purpose. I

have herein described how malleable ingots of 'iron or steel are to be made by a'direct process of refinement from crude iron without the application of heat-or fuel to the iron during the process,' except such heat as is generated by the introduction of oxygen into the metal; and I will-now describe a modification of the process by which I prepare the iron for conversion into steel of asuperior quality. For this purpose I proceed in the first place to refine the crude iron in the manner hereinbefore described, carrying on the process until the most complete refinement is effected and the iron isasnearly pureas may be. Ithcn pour the fluid iron into water, by which it becomes granulated, and thegrains or shots soproduced are afterward to be cbnverted int'o steel bythe process of cementationwith charcoal in uprightretortsin the manner described in a patent granted to me in (:reat Britain ibr improvements in the manufacture of cast-steel, and mixtures of steel and east-iron and hear ing date the 18th day of June, 1855. The

'blisteusteelso produced .may be. melted in crucibles, as at present generally practised in the manufacture of cast-steehorby any other suitable mcans.-

Having thus described my invention and the manner in which the same may be carried into practical operation, I desire it to beunderstood that I do not confine myself to the precise details herein specified, provided that the pe-t culiar character of my said invention be re tained. I do not claim injecting streams of air or steam into molten iron for the purpose of refining iron, that'beinga process known and used before; but

Witnesses:

JNO. swoon, Lincolns Inn, London. THOS. BROWN, p

2 George Yard; LnmbardSh, London.

HENRY BEssEMEa I

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