US1082359A - Process of making steel. - Google Patents

Description

I it sirATEs PAUL r. REESE AND SAMUEL s. WALES, or MNNHALL, PENNSXLVANIA, ASSIGNORS T cARNEGIErs'rnEL COMPANY, or PITTSBURGH, PENNSYLVANIA, A conronea'rxoNor New, JERSEY.

rnoonss orv MAKiNe 'sTEEL. I

Be it known that we, PAUL P. REESE and SAMUEL S. WALES, both; citizens of the United States, residing at" .Munhall, in the county of Allegheny and State of Pennsylvanla, have invented a new and useful Process of Making Steel, of which the following is a specification.

Our invention relates to the manufacture of open hearth steel of all grades in which the cost of making the steel is not necessarily the governing factor, and while not restricted to such uses, more particularly relates to the manufacture of high grade spe cial steels and alloy steels, andespecially those employed in making armor plates, protective deck plates, and like materials.

'One object of our invention is to provide an improved process of making steel whereby the temperature and composition of the bath are regulated and the interval of time required in making or completing the heats ofsteel is varied to the end that the changes in temperature and composition are at all times under the control of the melt'er and thedesired composition is obtained at the time the requiredpouring temperature of the bath is attained.

A further object of this invention is to provide a novel process of making steel whereby the rate or speed at which the carbon i's removed or lessened is regulated and controlled andj the too rapid elimination of carbon; is prevented, the necessity of pigging back the heats is avoided and overcome and the time required in making thesteel is lessened or increased as desired.

Another object of our invention is to provide an improved process of making alloy steel by theuse of which the necessity of carbon "additions other than the amount contained in, the final addition of manganese,

chrome, or other'a'lloy addedat the comple- 'tionjof, the heats; is avoided and rendered ei fe e r n; In'c'arrymg out the steps of our improved process, charges, preferably havlng itlper ,cenhgiron as a minimu1n,"are put into the nemesis the usual, manner. No ore, mill- 50.

scaleor "o xid" is used 'iirma'king'up the charge, and iron is not employed later in pigging back the heats.

After the charge has been completely melt Specification of Letters Patent.

Application filed January 23,19 2. Serial No. 672,970.

Patented neclae, 1913.

ed, (which is preferably effected asrapidly' as possible) and the lime has risen to form the slag, an analysis is made and the carbon content of thebath determined. This carbon content will vary largely and should ordinarily be above .75 per cent. An ore addition. is then made to the bath of'an amount approximating .01 of 1 per cent. of

ore for each point of carbon to be removed.

Should, after the ore has been thoroughly worked into the bath, the carbon remain at the same or a higher point, a further addition of ore is made at the rate of approximately one-half the amount of the first'ad' dition ,per point of carbon, and the carbon is lessened to approximately .35 to .45 per cent. Additions of ore are not made after the carbon is lessened to about .65 per cent.

When the successive carbon determinations, which are taken'at frequent intervals, show the carbon content of the bath to be lessened to about .40 per cent, additionsof' manganese are made to the bath, the amount of these additions being equal to about .2.

of 1 per cent: of. manganese or at'the rate of about ,two pounds of per cent. ferro manganese to each one thousand'pounds of Preferably,

vals after the carbon has been reduced to-between .35 and .45 per cent.,'or a totalof .8

per cent. in all. 1In'this way further dropping or elimination of the carbon is retarded, and the removal of the last fewpoints of carbon is caused to extend over a con. siderable time interval justprior tothe'tapping operation. I 7

Instead of making the last one or two manganese additions in amounts of .2 of 1 per cent, these amounts may be split up into separately added quantities of .1v of l per cent. each. i

The additions of manganese-are. made. from'time to time soas to preferably pre-v vent the heat of steel being-finished when,

the carbon'content is dropping faster. than at a rate of one'point (1.01'.per cent.) carbon I ina time interval of three minutes. I y As it is desired to, tap the heats of steel when the desired carbon content is reached, (the amount of carbon added by the additions offerro alloys being taken into conand in making alloy steels, the alloying metals are added as are desired, being added I in the usual manner, eitherin the furnace or in the ladle.

The residual manganese will orilinarily provide the desired amount of' manganese in the finished, steel. Manganese-may be added in the ladle or at the time ofitapping when found necessaryor desirable. Should it becorse necessary to hold a heat of steel after being ready to tap, further additions of manganese aremade from time to time, the quantity added and the number of additions made depending upon the time interval elapsing between the time the heat reaches the tapping vtemperature in readiness totap and the time of tapping.

The process of making high carbon steels is substantially the same as hereinbefore described, the charge being calculated to give a melting point sufficiently high to avoid the necessity of carbon additions other than the amount obtained from the carbon contained in the final addition'ofmanganese,

the chrome, or other alloyingmetal.

In making ordinary steel, the above described steps will be carried out, the additions of manganese being regulated so as to bring the carbon content to the desired point about the time the temperature of the the manner before described; I

The advantages of our invention will be apparent to those skilled in the art. By the use of ferro manganese during the refining bathreaches the right point for tapping in of the metal in the furnace, the reduction or elimination of carbon in the bath is-at all times under the control of the melter and.

the making of heats in which the carbon falls below the desired content and requires carburizing is prevented, while the making of heats which are at a proper tapping temperature before the carbon has been reduced to the desired point is avoided.-

The use of successive additionsofmanganese in the bath results ina more thorough and complete removal of sulfur.

The use of ore, cinder or other iron oxid in forming the charge is rendered unnecessary, and the necessity of using coal is over- Variations in the steps of our process maybe -made without departing from our invention as defined in the claims. The number of additions of manganese may be increased or decreased, and a change in the amount of manganese in each addition may or may not be made as desired, and the tapping the steel when We -claim:

1. The process of making steel consisting in melting the metallic charge, making additions of ore to the bath to remove carbon therefrom, and then making additions of manganese thereto to check and control the further removal of carbon. 7 1

2. The process of making steel consisting in melting a charge of scrap steel and iron in. which the ercentage of steel predominates, making additions of ore to the bath to remove carbon therefrom, and then making additions of manganese thereto to checkand control the further removal of carbon.

3. The process of making steel consisting in melting a charge of scrap steel and iron, making additions of ore to the bath to re-. move. carbon therefrom, and then making successive additions of manganese thereto to thereby check and control the further re-- moval of carbon.

4. The process of making steel consisting in rapidly melting a charge of scrap steel and iron in which the percentagejof steel making additions of ore to predominates,

and other metalloids in the remove carbon charge, and'then checking further removal of carbon therefrom by the addition of successively added quantities of manganese.

5. The process of making steelconsisting in melting a charge of scrap steel andiron in which the percentage of steel predominates, making additions of ore to remove carbon and other metalloids therefrom, and

' then preventing further removal of carbon by the addition of manganese thereto and tapping the steel when the tapping point is reached. v

6. The process of making steel consisting in rapidly melting a charge of scrap steel and iron in which the percentage of steel predominates, making additions of ore to remove carbon and other metalloids therefrom, then retarding further removal of carbon by additions of successively added quantities of manganese while bringing the bath to the tapping temperature and then tapping.

7 The process of making steel consisting in melting the metallic'charge, making additions of ore to rapidly remove a portion ofthe carbon, then adding manganese in separate successive quantities to retard and prevent further removal of carbon and then the tapping point is reached, the manganese being added in separate quantities to thereby first retard and then for a short time intervalprior totapping the steel substantially prevent further removal of carbon therefrom.

8. The process of making steel consisting in making additions of ore to the molten charge. of metal to rapidly remove a portion of the carbon, then adding manganese to reterd and prevent further removal of carbon and then tapping the steel when the taping oint is reached the manganese being adde in separate quantities .to thereby sub stantially, prevent further removal of carbon for a short time interval prior to tapping the steel.

In testimony whereof, we havehereurito set our hands.

PAUL P. REESE. SAMUEL S. WALES.

Witnesses:

GEO. B. BLEMING, R. D. Lrrrm,