US938892A - Process of treating manganese-steel ingots. - Google Patents

Description

- Processes of Treating To all whom it may concern:

, UNITED STATES PATENT OFFICE. WINFI ELD S. POTTER, F MAHWAHEVTJERSEY, ASSIGNOiB, 'IO MANGANESE STEEL RAIL COMPANZ OF MAHWAH, N1 ]W ERSEY, A CORPORATION JERSEY.

PROCESS OF TREATING MANGANESE-QTEEL ,INGOTD.

Specification of Letters Patent.

Application filed January 31, 1907.

No Drawing.

Be it known that I, W INFIELD S. Porrnn, a citizen of the United States, and a resident of Mahwah, in the count of Bergen. and

State of New Jersey, have made and invent ed certain new and useful Improvements in Manga11ese-Steel lnQ gots, of which the following is a specifica- I sectional area. Many attempts have hereto is firstslowly heate a temperaturebetween 315: C. and 540-'C.; in case, however, the mgot ls to be subjected tlon.

My invention relates to the'production of manganese steel,'an d more particularly to the production of ingots hav1ng a large cross fore been made to work what is commonly known and referred to as manganese steel, by rolling 01' forging, but with no success in the case of large ingots, or with finished articles having a largecross sectional area, and

with only partial success in the case of plain shapes,'such as bars and flats having a relatively small cross sectional area.

I have discovered that the failure to roll or forge large ingots, to large and diflicult shapes, such as rails, has been due to the treatment to which the metal has been subjectedyand the object of'my invention is to so treat the metal as will provide a manganese steelingot of any desired dimensions and possessed of such characteristics as will enable or permit the same to be subsequently rolled, forged, pressed, or otherwise formed into an) desired shapes, and of any desired dimensions, such for instance asrailway rails, fparts of crushing and other machines, also ats and sheets from which to form screens and bottoms and sides of chutes for sizin and handling crushed ores, etc. without an er' of rupture inthe subsequent heating an forming. These ingots are produced by the novel method or process hereinpresent invention.

, In practice the ingot to be treated, if cold, to a dull red heat or to to the treatment'hereinafter described immesov - necessary. After; arriving at the dull red.

-diately afterb'eing cast or while still at temperatures above the recrystallization point throughout from the" heat of casting, this preliminary lieati iig" step is of course unheat or lower temperature, the metal is heat Serial No. 855,082.

temperature somewhat belowthe pointwhere the ingot begins to weaken,-and which point I termthe upper-critical point of the metal.

Patented Nov. 2, 1909.

ed either slowly or rapidly as desired, we

The temperature of this upper-critical point, 7

' will, of course, vary-according to the analysis of the metal, say from approximately 1050" C. to 1120? C. Froma temperature slightly below the upper-critical point, say for exam; ple, about 1M0 0., the ingot is slowly heated in anon-oxidizing fluid to atemperatur'e the temperaturev at this stage of the process,

to a point between 1150? G. and 1205 0., al-' though itwill be understood that this higher temperature may be greater or less according to the analysis of the steel, and the facilities at hand for quickly and expeditiously han i dling the metal at? its different stages of treatment, and also the facilities for obtaining accurately the temperatures of the metal at all times, it being essential only that the temperature of the entire mass of metal shall be above the upper-critical point and below the melting point, that is, that the metal shall be in a soft and plastic condition.

After the ingot has been subjectedto a temperature ator above the upper-critical point, preferably to atemperature between 1150 C. and 1205 (1, and after the mass'of metal has been uniformly heated throughout, tho temperature is'then lowered rapidly to a point below the upper-critical point, preferably to a temperature just above the recrystallization point, which will, of course, vary according to the analysis of the metal.

from approximately 600 C. to 700 C. If

,stream of cold gas or steam therein, and

around the metal, although of course, such cooling may be effected in a-se'paratecham-a bar or compartment designed for the purpose. This rapid lowering of the tem erature cools the skin .or outer surface 0 the ingot. I This vrapid lowering of the. tempera- I 10, metal and also the cohesion ofthepartieles thereof, and renders the metal of such a na- -ture'as to be much better adapted for subsequent rolling or forging. After the metal has been rapidly cooled to the desired temperature as .above described, the cooling is arrested in orderthat :thebody' of metal may become of uniformtemperature throughout, whereupon the rapid cooling is continued if necessary until the entire mass is finel crystallized; it may then be reheated .for t e rolls or allowed to cool'to the temperature of the atmosphere.

The rapid cooling, however, should not be continued much below the dull red heat nor below 425. C. to 480 C.- to avoid the setting up of internal strains in the ingot, and the coolin below the dull red heat should be carrie on uniformly until the temperature of the ingot reaches the temperature of the atmosphere.

As before stated, both the heating andinitial cooling steps are preferably e cted in a non-oxidizing fluid, either liquid or gas, the object bein to prevent the burning and consequent wea ening of the outer layer-s ot metal and 'to preserve a strong, tough, continuous, unbroken or unchecked skin or surface, in order that the latter shall retain the necessary strength and toughness while 40shrinking to cause the welding of the interior mass of metal while in its soft or plastic condition, and in order also to prevent the breaking or disintegration of the metal in its subsequeht treatment of forging 5 or rolling, which isiliable to occur when the outer skin or layers of metal are crackedor checked.

Ihave found in practice that when an ingot of manganese steel 13 thus treated, it.

59 'is of such a nature and possesses such characteristics as will enable it to be subsequently re-heated to a higher and more desirable temperature for the rolls, than is otherwise possible, permitting it to be rolled or forged into any desirable shapes of any suitable di-" mensions. The metal is of increased densit the metal being more tightl and closelywe ded together, and possesse of greater eohesive'power, while at the same time it retains the desirable fine crystallization and an outer. strong, toughand unchecked skin.

I While I have above mentioned .thetem peratures to w i'ehgI have found in practice themetal is," referably raised or lowered,

v yet Iw/ou' l ave/it understood that good results may be obtained atvlower tom ra-' times and prolonging the time to whic the metal should be sub ected thereto; ood re-n sults may also be obtained with big or tamperatures, and therefore I do not limit or? aestrict my claims to the temperatures given,

Having fully described my invention, what I claim as new and desire to secure by ters Patent, is: i 1 5 1. In the treatment of manganese ste'el'thc processherein described of rapidly cooling the exterior of the metal from a temperatur above the upper critical point.

2. In the treatment of manganese steoha br the process herein described of rapidly coolit ing the exterior of the metal while the interior is at a temperature above the upper.

critical point.

3. In the treatment of manganese steel the 35 process herein described of rapidly cooling the exterior of the metal in a non-oxidizing fluid while the interior is at a temperatun above the upper critical point, .4. In the treatment of manganese steel,

the )rocess herein described consisting in t rapi ly cooling the exterior of the metal from a temperature between the upper- 1, critical point and the meltingtemperatur' to a dull red heat and above 425 (3. and,- then uniformly cooling the metal to atmos- 1 pheric temperature. a v

The treatment of manganese steel which consists in arresting the rapid cooling of the metal at the temperature described maintainin said temperature until the metal-is of substantially uniform temperature throughout, and finally cooling the metal to atmospheric temperature.

6. The treatment of manganese steel 10. whih consists in heating the metal to the highest predetermined temperature, then rapidly cooling the metal to a temperature between the upper critical oint and a dull red heat, then arresting t e cooling, flnd lli. then finally cooling the metal to atmospheric; temperature.

7. In the treatment'of manganese steel,"- the process herein described-pf arresting thew; cooling of the exterior of the metal at a temperature slightly above the recrystallization point. while the interior is in a Soft and plastic condition.

8. In the treatment of manganese steel,.

the process herein described of rapidly cool- 1 ing the exterior of the metal to a temperature sli h't-ly above the l e-crystallization point w iile the interior is in; a softand; plastic condition, and then permitting the nmss of metal to "become of uniform. tem

perature throughout. I A p 9. In" the treatment of manganese steel, the process herein described of rapidly cool: ing the exterior of the metal to a tempera ture slightly above the recrystallizati0n 0 point while the lnterior is in a soft and plast c condition, maintaining thetempera- "in a non-oxidizing fluid uniformly and then cooling the metal to the temperature ing the exterior of the metal to a tempera- .determined point above 450 degrees (1, main- I'nass of metal to atmospheric temperature.

metalto the desired temperature.

point while the, interior is. in a soft and plastic condition, then permitting the mass of metal to become of uniform temperature throughout, and then rapidly cooling the metal to atemperature below the re-crystallization point. 10. In the treatment of manganese steel, the process herein described'of rapidly cooling the exteriorof the metal to a tempera ture slightly above the re-crystallization ture until the mass of metal becomes of uniform temperature throughout, then rapidly cooling the metal to a temperature above a dull red heat. 4

11. In the treatment of manganese steel, the process herein described of rapidly coolture slightly above the re-crystallization point while the interior is in a soft and plastic condition, maintaining this temperature until the mass of metal becomes of uniform temperature throughout, rapidly cooling until the temperature of the exterior at a pretaining this temperature tintilithe mass of metal becomes of uniform temperature throughout, and then slowly cooling the 12. The process of treating manganese steel which consists in heating the metal to a temperature below the upper critical point, then heating the metal slowly and uniformly to a temperature above the upper critical point and below the melting point and maintaining said temperature until'the metal is in a soft'and plastic condition throughout and then cooling the metal to the temperature desired.

13. The process of treating manganese steel which consists in heating'the exterior of the metalrapidly to a predetermined temperature below the upper critical point, then heating the metal throughout to the said predetermined temperature, then heating the metal.uniformly and slowly to a. temperature above the upper critical and be-' low the melting point and then cooling the 14. The process of treating manganese steel which consists in heating the metal in a non-oxidizing fluid uniformly throughout to a predetermined ten'iperature below the upper critical point, then heating the metal slowly to a temperature above the upper critical point and below the melting point, and maintaining said temperature until the metal is uniformly heated throughout and desired.

15. The process of treating manganesesteel ingots which consists in heating the ingot to a temperature above the upper- .ing the temperature rapidly to below said 'hpper-critieal point of the metal, and maintaining the temperature at a predetermined ture throughout.

- upper-critical pointof the metal, and lower-" I point until the ingot is of uniform tempera- 17. The process .of treating manganese steel ingots. which consists in slowly heating the ingotmfr'om a point below the uppercritit-al point to a temperature above sald upper-critical point and below the melting point of the metal and rapidly lowering the temperature to a temperature below the upper-critical pointand above the re-crystallization point in a non-oxidizing mediumand maintainingsaid temperature until the ingot is of uniform temperature throughout, substantially as described. I

18. The process of treating manganese steel which consists in heating the metal throughout to a' temperature belowthe uppercritical point, then heating the metal uniformly to a temperature above the upper critical point and then cooling the exteriou of the metal rapidly to a temperature below the upper critical point and below the interior of said metal.

1.9. The process of treating manganese steel, which consists in heating the metal to 'a temperature below the upper critical point, then heating the same uniformly to a temperature above the upper critical point, then cooling the exter or of said metal rapidly below the upper critical point, causing the same to become of uniform temperature throughout, and then cooling the same to a temperature below the recrystallization point.

20. The process of treating manganese steel which consists in heating the metal .to a' tcmperature below the upper critical point heating the same uniformly to a temperature above the upper critical point, then rapidly cooling the exterior of said metal toia temperature below the upper critical point, causing the same to become of uniform temperature throughout, and then rapidly coohng the same .to a temperature below the recrystallization point where themetal is finely crystallized throughout.

21. The process of treating -manganese steel which consists in heating the metal to a temperature below the upper criticalpoint, heating the same uniformly to a temperature above the upper critical point, then rapidly coolingthe exterior of said metal to a temperature below the upper critical point, causing thesame to become of uniform temperature throughout, then rapidly cooling the same to a temperature below the re-crystallization point where the metal body is terior of the metal to a temperature below the up er critical point, and above the recrystal ization oint, arresting the cooling until the metal becomes of uniform temperature throughout, and then rapidly cooling said metal to a temperature below the .recrystalli'zation then rapidly heating the metal to a tem eraperature below the sai point where the metal 'is finely crystallize I 23. The process of treating manganese steel ingots which consists in slowly heating the-ingot to a temperature above 450 0.,

ture below .the upper-critical point, s owly heating the same in a non-oxidizing medium to a temperature below the melting point and then coolin the ingot to a temg upper-critical point.

24. The process of treating manganese steel ingots which consists in heating the ingot to a temperature between the uppercr tical point and the meltingpoint, rapidly cooling th same to a temperature below the upper-critical point and above'the recrystallization point, then causing the same to heating the heating the become of an even tem erature throughout and then finally rapid y cooling the same to produce a fine crystalline structure.

25. The process of treating a manganese steel ingot, which consists in'heatin it to a temperature above the upper critica point of the metal, rapidly cooling the inlgotto a temperature above that of re-crysta ization retaining the ingot at this temperature until of equaltemperature throughout, and finally lowering the to erat-ure to a that of re-crystal ization.

26. The process of treating manganese point below to a temperature below 1050 then uniformly heating the same in a non-oxidizing fluid to a temperature below its melting point, and then cooling the same.

27. The process of treating manganese steel, which consists in uniformly heating the metal from temperatures above 1050 C. to temperatures below the melting point,

the metal I in a non-oxidizing atmosphere, then rapidly a cooling the same to a temperature above 450 0., and finally cooling the metal to atmospheric temperature. i.

Signed at New York borou h ofManhattan in the county of New ork and State of New York this 24th day of January A. D. 1907.

WINFIELD S. POTTER.

Witnesses:

GEORGE CooK, A. M. AUSTINu