US1080590A - Metal article. - Google Patents

Description

J. 0. RUSSELL. METAL ARTICLE. APPLIUATION FILED DEG.30,1912.

1,080,590, Patented Dec. 9, 1913.

'n uu Allegheny end State or 1,.os0,5oo.

Speolflcetion of Letters Patent. Application filed December-; 1912. Serial E0, 739,191.

Patented; Dec. e, 1913.

To-ail whom time concern-4 Be known that 1, JAMES C- RUSSELL, a resident of Pittsburgh, in the county of Pennsylvania, have rnvef ted a new and useful Improvement in Metal Articles; and I d following to'be 51 full, clear,- scxgfti on thereof;

y invention relates other steel articles and has special reference to such a; quot-y 0% article wherein the crystalline structure of the: metal oomand exact deprising the some willbe-brolren up and the unlikely to become broken by any sudden shocks or changes atmospheric ccnditione.

The object of my invention is to provide a cheap, simple and efi'rcient form of railroad mil which will be, treated. in such a manner that the same will lee-adapted to be I ditions so that used on any kind of a road and will, on ac" count of its tough durable nature, tend to eliminate the frequent and numerous acciden-ts of the present day ceased by the breaking of such railroad rails.

My inventioneonsists, generally stated, in the novel ua-li-tyof railroad rail and other steel a'rtic' es, wherein the interior of the same is composed of hard material known as martensite while the outer surface or exterior of the some consists of a soft, tough material known as troostite, although no break line between the different qualities will be apparent, as they gradually blend into one another.

My improved railroad rail and other similar articles such as bars, rods, etc, are subjected to treatment in an apparatus similar' to that described inmy U.- S. Letters Patent, No. 993,411, granted May'irOth, 1911, for an improvement in apparatus for treat ing railroad rails and other like articles.

It is well known that in the present method of rolling and manufacturing steel railroad rails the finished articles are likeli to heoome broken by any sudden shoe any sudden change in the atmospheric conby the breaking of rails on railroad tracks trains are derailed, pwssen gers oftentimes killed or injured b reason thereof on account of the heret ore imperfect, inherent, nature: of the some hereby declare the to railroad rails and about seven or The presence 5 When steel has been i is then allowed to cool it will first change or by,

is also well known that in the present qualrty oi railrosd rail used throughout the country the molecules composing the some generally appear to form a simple, homeoneous substance, but when placed under .a.

- microscope are seen to be e conglomeratlon 01E crystals of difierent'. substances. This crystallization, or, what is known as crys; talline structure, is broken up in my lin roved article and the whole really made to e what it appears to the ntthecl eye in the old mil, vie, a solid, simple homogeneous ,mess of metal.

mll thus rendered tough and durable and E vhaving is intended to produce a metal which will be 7 soft and tough on My invention. covers the treating of steel .36 or greater per cent. carbon, and

1 I the exterior end'hard on the interior, 1n order that the same cannot vbe crooked or particles chippedfromLtlie same and the tough exterior of the same will hold the inner pertlcles together and prevent the whole article from becoming disru oted or broken.

bteel when heated to a; temperature of eight hundred degrees centigrede willpresent a pearance and will be in what is known as aust'enite condition. Ifthis steel were allowed to cool slowly to atmospheric temperatu-re it would revert to its original quality, which is known as pearlite,

although e few molecules l of the austenite would remain; oi carbon in the steelg w'ill tend to prevent the reversion of the entire mass from eustcnite to pcarlite, so that high carbrightcherry red aphon steel in slowly cooling will sometimes I retain as much as 70% austenite molecules.

If, for instance, the steel could contair; n0

: carbon whatsoever it would revert from eostemi-te to peerlite absolutely. During the change from austenite to pearlite steel will pass through several transition stages which are not,

under ordinary circumstances, permanent conditions or qualities of steel. heated to austenite and If it then continues to cool to mertensite.

fi'rom martensitc :to troostite it will ch enge es before mentioned, the presence themolecules from reverting to peerlite.

To enable others skilled in, the art to which my invention appertains to treat and use my improved railroad rail and other steel articles I will describe the same more fully referring to the accompanying drawing in which the figure shows a steel railroad rail during the process of treatment.

The process by wlnch I obtain my improved steel article is as follows :The rail or other article which has been treated to austenite is first passed into abath of oil and passes slowly through such bath so that entirely passing through the same consumes but a few seconds of time. The rail then continues in a bath of oil but water is forced at a pressure through the oil and against the surface of the head of the rail so that by the time the rail emerges from the baths in the trough it is cooled almost to atmospheric temperature. When the rail or bar A is first passed into the oil bath its condition is austenite and as it continues through this bath the outer part a of the same, to a depth of about one-sixteenth of an inch, is brought down to troostite condition, while the material 1) within the inner layer is not as yet affected by the liquid bath. Now if the rail were at this point taken from the bath the hot inner metal of the same would bring the outer surface back to a red heat and the whole would be austenite at a temperature of about one hundred degrees, or thereabout, less than when entering the bath. But instead of withdrawing the rail it is allowed to continue through the oil bath 0 but water d is forced under pressure against the head of the same from'pipcs .g. The rail during this stage ofrthe treatment is shown in the drawing. As it is subjected to this bath or treatment the outside layer act the same being in a troostite condition, while the inner metal I) is still in anaustenite condition, the action of cold water d upon the surface of the same will tend to trap or i hold the troostite material in this same con- L 5 dition, while the rapid cooling of the inner austenite will bring the same to martensite. This is effected by the action of the cold water on the head of the rail and the martensite is trapped in the interior just as the troostite is trappedon the exterior. The web and flange of the rail A are allowed to pass through the oil bath, unaffected by water until they are almost entirely troostite, whereupon the water is forced againstsaid web and flange to trap the troostite so that there is only a small portion of martensite present. Thus the finished material will be martensite on the interior and troostite" on the exterior. This will give a material having a hard body covered by an outside layer or exterior of tough durable steel, and homogeneous throughout as to its chemical characteris- .tics.

Materials having a soft interior and ahard exterior have been made but they are objectionable in many ways because the hard outer surface can be cracked or particles chipped from the same, whilein my improved rail or other article the outer material of troostite will form a tough durable inclosure for the hard metal so that it cannot be chipped or broken and the troostite will tend tohold the particles or molecules comprising the martensite interior firmly together.

It is possible to carry out this treatment and produce my improved article without using an oil bath. This is accomplished by using first, a bath of warm or hot water and this will bring the outer surface down to a troostite condition-then a bath of Warm water having cold water under pressure forced through the same and against the surface of the article. This will tend to trap the troostite and will also trap the martensite within the same.

Although it is possible to obtain my improved article by using water baths of diferent temperatures, -I prefer the oil treatment as the water after being forced through the oil and against the surface of the article will immediately seek its level and pass downward through the oil where it will be carried off as explained in my United 5 States patent referred to above.

It will be readily seen that on account of the oil maintaining the higher level and the cold water being forced in at all times the oil will become heated to a higher tem- 10 perature as it will retain a great deal of the heat from the rail or article passing through it. The liquids being at differentv temperatures will tend to prevent the material from changing from austenite to pearl- 105 ite and by breaking up the erystallinestructure will produce a material superior to any heretofore manufactured and one which numerous tests and experiments have shown to withstand shocks which would break the 110 ordinary similar article before such treatment. In fact in the case of a rail placed under test before and after treatment, such as described, my new article was formed to withstand a shock twice as great as that 115 necessary to fracture the article before treatment. The need of an article of this kind,

- the inside or center of such article will be of a hard martensite material, which will allow the same to bend double without fracturin it. It will also be seen that steel of any s ape or size may be thus treated and the article produced will have the qualities 5 hereinbefore mentioned;

What I claim as m vinvention and desire t o secure by Letters atent is A steel articlehom'ogeneous asto its chemical characteristics having its exterior comfiosed of tough material and its interior of 10 ard material.

In testimony whereof, I the said JAMES C. RUSSELL have hereunto set my hand.

JAMES (J. RUSSELL.

Witnesses:

T. B. HUMPnmEs, J. N. 000KB.

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