US2070889A

US2070889A - Rail treatment method

Info

Publication number: US2070889A
Application number: US660544A
Authority: US
Inventors: Royal E Frickey; Arion S Kalenborn
Original assignee: Welding Service Inc
Current assignee: Welding Service Inc
Priority date: 1933-03-13
Filing date: 1933-03-13
Publication date: 1937-02-16
Anticipated expiration: 1954-02-16

Description

Feb. 16, 1937. R. E. FRlcKEY ET Al. 2,070,839

RAIL TREATMENT METHOD Filed March 13, 1933 4 Sheets-Sheet 1 FIE. J

mer/0N .sf fran/30g Feb. 16, 1937.

R. E. FRICKEY Er Al. 2,070,889

RAIL TREATMENT METHOD` Filed March 15, 1953 4 Sheets-Sheet 2 l ATTORNE Feb. 16, 1937. A R E FR|CKEY ET AL 2,070,889

RAIL TREATMENT METHOD Filed Maron 13, 1953 4 ysheets-sheet 3 N Mfmrg A TTORNE YS.

Feb. 16, 1937. R. E. FRICKEY Er AL 2,070,889

RAIL TREATMENT METHOD Filed March l5, 1933 4 Sheets-Sheet 4 FIIE E r l i ATTORNEYs Patented Feb. 1e, 1937 l 2,070,889

, UNITED STATES PATENT OFFICE RAIL TREATDIENT METHOD Royal E. Frickey, Stan Francisco, and Arion S.

Kalenborn, Redwood City, Calif., assignors to Welding Service, Inc., San Francisco, Calif., a corporation of California Application March 13, 1933,- Serial No. 660,544

6 Claims. (Cl. 148-21) This invention relates generally to methods for paratus shown in?" Figure 4, in transverse crossthe treatment of railroad rails, to effect hardensection. ing of the same. It has particular application Figure 6 is a side elevational View, in transto the treatment of rail joints, to harden the upverse cross-section, showing apparatus utilized to per surfaces of the adjacent rail ends. eiect quenching of that area of the joint or rail 5 I In the past it has been proposed to harden rail which is heated by an electric arc. ends by generally heating the sameto a relatively Figure 7 is an end view of the apparatus shown high temperature of say 1500 F., by an oxyin Figure 6, certain portions beingbroken away acetylene torch, followed by rapid chilling with for clarity. water. After chilling a reheating was necessary Figure 8 is a plan view, showing parts of the are 10 to secure a proper temper. Such methods have heating apparatus.

not met with universal approval, due among Figure 9 is a diagrammatic vlew showing a other reasons to lack of uniformity of the degree portion of the path traced by the heating arc. of hardness produced, and to frequent breakage Figure 10 is a curve drawnto three dimensions,

of the heat treated portion caused both by severe showing a desirable heat distribution pattern. l5 stresses imposed by sudden quenching with water, The present specication is a continuation in andv by locked up stresses of large magnitude part of subject-matter disclosed in our application which result. Serial No. 612,066, entitled Rail treatment ap- It is an objectA of the present invention 'to proparatus, and application Serial No. 641,714, en-

vide a method for the hardening of railroad rails titled Heating apparatus. In said application 20 which will make possible uniformly good results Serial No. 612,066 we have disclosed and claimed in successive hardening operations, and which will an apparatus for the chilling of heated rails be well adapted for prevailing eldconditions. with oil, which can be utilized in conjunction with A further object of the invention is to provide the present method. Application Ser. No.

a method of the above character which will pro- 641,714, discloses and claims an apparatus utiliz- 25 duce a predetermined hardness pattern. ing an electric arc, for the heating of rails A further object of the invention is to provide preparatory to a chilling or quenching? operation. a method of the above character which will per- This machine can likewise be utilized in carrying mit the use of oil as a liquid chilling medium, but out the present method, as willbe presently .30 which will conserve the oil utilized for each explained.

30 treatment. When our Amethod is carried Vout in its pre- Another object of the invention is to provide a ferred form, it consists of four general steps rail hardening method which will not cause which are carried outin sequence. Thus as diadeleterious effects upon the rail being treated. grammatically illustrated in Fig. 1, the step l0 Further objects of the invention will appear is to preheatasection of the rail, which contains 35 y from the following description in which the the area or areas tobe hardened. The next step preferred embodiment of the invention has been following the pre-heating, is to heat the limited set forth in'detail in conjunction with the acarea or areas of the upper surface of the rail to companying drawings. The appended claims are4 be hardened, as indicated at Il. As` will be preseto be accorded arange of equivalents consistent ently explained, this heatmg can be accomplished 40 with the state of the prior art. e by traversing an electric arc o ver the area to be Referring to the drawings: IadenedhFollllownettietheatmlttlpggj Figure 1 1s a dmgram mustmtmg the preferred ture is chilled as indicated at I2, and following successive s teps l1n carrying out ourmethod. this chmingthere is a drawing Operation I3 to, 45

Flgure 2 1s a side elevational view, showing ap temper the hardened layer of metal paratus for eiectlnga preheating of the rail secwith respect to the sc caned Stel; of preheat ti.n or 30m? to be treatefi' ing, this can be accomplished in a number of Figure 3 is a cross-sect1onal view taken along Ways other than by .the use 'of the apparatus y the Ime 3 3 0f Figure 3 which we shall presently' describe. "Assuming 50 Figure 4 iS a View.` in transverse Cross-Section that the upper surfaces of `adjacent rail ends at illustrating a portion of the apparatus utilized to a rail joint are to be hardened, thepreheating eiect a heating of an area 0f the uppersurface should -extend for a substantial distance on` of the rail, by the use of an electric arc. either side of the center of the joint, beyond the 55 Figure 5 is a side elevational view of the aplocalized area to' be hardened. 55

. The preheating facilitates subsequent heating of the localized area of the upper surface of the rail by an electric arc, and makespossible cer- 4tain additional advantages, as will be presently explained. Although there is no specific critical I temperature to which the rail section must be preheated, in practice with rails now commonly which can be utilized with good results, is con- I1 is provided, which can be formed to afford structed as follows: A laminated magnetic core side depending. magnetic legs I8, a central magnetic leg 20, and an upper leg 2I adjoining the legs I8 and 20.- 'I'he laminations ofv the ,core are held together by suitable means, such as the end plates 22,'connected by tie rods 23. A winding 24 surrounds the central leg 20 and is-adapted to'be'connected to a suitable source of alternating lcurrent, such as a supply circuit having a frequency of 180 cycles. The lower edges of plates 22 are shown extended to engage the upper surface of the rail, thereby maintaining an air gap between the lower ends of the magnetic legs I8 and 2 0 and the upper surface of therail. Both Figs. 2A and 3 show the preheater positioned upon I arail at a rail joint, for heating the same. When the winding24 is connected to a source of alternating current for exciting the same, the -ball I9 of the rail forms la flux path between thelegs I8 and 28, and the varying magnetic flux which is thus caused to pass thru the'rail causes heating Aof the rail ball both'by induced e'ddy currents and hysteresis loss. In order to enable an o erator to gaugethe amount of heat input into the rail,

it is desirable to include a watt-hour meter in the exciting circuit. Knowing the amount of watt-hour consumption-required for a definite desired amount-of preheating under certain con# diticns, the operator can terminate the preheating operation in accordance with the reading of the watt-.hour meter; with the knowledge that a predetermined temperature level has. been attained. It is also possible for the operator to continue the preheating until the temperature has risen to the desired value, as determined by a pyrometer, thermometer, or other suitable heat indicating o r recording instrument.

Apparatus, utilizing an electric arc, for heating a limited area of the upper surface of the rail, has been described in` detail in the afore-Q said application Ser. No. 641,714, and a part of such apparatus has been illustrated in Figs.l 4

. and 5. 'I'he parts illustrated in these figures inare connected to mechanism for traversing theelectrode 34 over the upper surface of the rail encompassed by the structure 3l. It may be explained that this actuating mechanism traverses the arc simultaneously in two directions, one being lateral of the rail, and theother longitudinally of the rail. In other words the movements of the electrode, when an arc is maintained between the lower end of the electrode andthe upper surface of the rail, causes the arc to repeatedly traverse the upper surface of the rail in accordance with a predetermined pattern, so that this upper surface and the layer of metal adjacent the same is heated to a relatively high temperature. Reciprocating movement of plate 33, in conjunction with electrode 34, is permitted by having this plate supported in part upon a longitudinal rollerl 39. The ends of this roller are pivotally carried by spaced support members 4I, which are also connected to the box structure,

. and to the frame of the remainder of the ma-4 chine. Transverse lrollers 42 serve. to engage roller 39, and are pivotally carried by the outer end of plate 33.

Suitable means for reciprocating the electrodes 34 with respect to the rail has been illustrated particularly in Fig. 8. Thus af carriage 44 is provided, having its ends slidably supported by bars 46. These bars extend parallel to each other and longitudinally with respectto the rail, and have their ends secured to the main frame 43. Supported by carriage 44, are the cams 41 and 48, which are fixed to shafts extending from a gear box 49.- "."he train of gears housed witliin'box 49 are driven from a suitable source of power, such as an electric motor 5I. The groove of cam 41 is engaged by a roller 52, which in turn is journaled and connected to the end of a reciprocable rod 53. The end of rod 53 nearest the rail being operated upon, hasa pivotal connection 54, to arms 31. Cam 48 has its groove engaged by a roller 56, which in turn is-journaled to a stationv ary bracket51. Rotation of cam 48 at a predetermined speed reciprocates carriage 44 longitudinally of the rail and thus reciprocates the elec` trode 34 in the same manner., Rotation of cam 41 reciprocates rod 53 and electrode 34 laterally odd ratio, rather than even. Therefore in its travel acrossthe rail, electrode 34 follows azigzag course, but in successive passes over the rail in a longitudinal direction, the paths traced by the arc overlap. Thus during a normal period o f operation substantially every portion of the lsurface of th'e rail over vthe area -being heated, is contacted by the arc. In Fig. 9 the line I indicates the zig-zag course for the arc, as has been explained.

In operating the apparatus of Figs. 4, 5 and 8, the current input to the arc is maintained'substantiallyconstant. Therefore the input of heat tothe rail will'depend largely upon the ,manner in which cams 4,1 and 48 are formed. Since uniformity of resulting hardness is desired over4 a substantial area of the rail ends at a joint, cams 41-and 48 should be so designed that the resultlng heating of the rail surfaces, followed by chilling and drawing in accordance with Vour method,

produces a desired hardness pattern. By uniformity of resulting hardness we have reference not only to uniform surface hardness in directions lateral and longitudinal of the rail, over the area being treated, but also substantial uniformity with respect to the depth of the hardened layer of metal. We have found that heat imparted to the side edges of the railtends to dissipate into the atmosphere and cool more rapidly than intermediate surface portions. Likewise We have found that the longitudinal end portions of the area being heated by the arc, require considerably more heating than other portions to secure the desired heat and ultimate hardness patterns, due to rapid conduction of heat to the cooler portions of the rail. We therefore so proportion cams 41 and, that a greater amount of heat is transferred from the arc tothe side edge portions of the rail, as compared to the intermediate portions, and also a considerably greater amount of heat to the end portions of the area being traced by the arc, as compared `to both the intermediate area and intermediate side portions. This 'can-be explained more clearly by reference to the heat input curves of Fig. l0. which are plotted with respect to three dimensions. Curves 2, because of their upwardly curved ends, show that a considerably greater amount ci heat is being imparted .to the side edge portions oi the rail. Curve 3 on the other hand shows, because of its upwardly curved ends,

a considerably greater amount of heat input in the end portions of the area being traced by the arc. Curves 2a show that even at the end portions of the area beingtraeed by the arc, a somewhat greater amount of heat input occurs near y the side edges of the rail, as compared to intermediate portions. Curves 3a show that even along the side edge portions of the rail, the ends receive considerable more heat. Thus in general, considering a section lateral of the rail, the side edges of the area traced by the arc probably receive from 15 to 25% more heat input, than intermediate portions. Considering a longitudinal section intermediate'of the rail, the end portions of the 'area being traced by the arc likewise receive from 15 to 25% more heat input than intermediate portions. A considerable part of the area traced by the arc, lying within both the ends and side edges of this area, receives heat comparatively uniformly. The proper design to use for cams 41 and 48, to secure the results desired, will vary somewhat for varying conditions of operation and the hardness pattern desired.

In Figs. 6 and '7, we have shown a part of the l apparatus or machine disclosed and claimed in our aforesaid application 612,066, and which is preferably utilized in `chilling the metal heated by the electric arc. The parts illustrated include a pair of open-bottomed boxes or receptacles 66, the lower edges of which are provided with s'ealing rings or gaskets 61 to engage the upper surface of the rail ball. Oil as a chilling medium is introduced into boxes 68. Oil can be removed from the boxes after being introduced into the same, through pipe fittings 69. These fittings may communicate with the interior of the boxes 66, thru check valves 1 I. As

explained in said copendin'g application 612,066,

in the complete machine of preferred form, oil is introduced into the boxes 66 thru'iitting 68 under a substantially constant head and at a predetermined temperature from a storage reservoir. Shortly thereafter, when pools of oil have been formed within the boxes 66, oil is withdrawn thru lthe boxes thru fittings -69 at a predetermined rate, and eventually returned to the storage reservoir for reuse. After a predetermined amount of oil has been introduced into the boxes thru fittings 68, further flow of oil is discontinued, but the withdrawal of oil thru fittings 69 is continued until substantially all of the oil has been removed. When these operations are properly controlled, Leither manually by an operator, or automatically, a predetermined amount of chilling of the rail by oil can be accomplished. In other words the time period of chilling, and likewise the amount of heat removed by the oil from the rail, can be 66, by way of pipe fittingspredetermined and controlled, assuming given temperature conditions for the rail at the beginning of. a chilling operation.

Our method can now be reviewed in entirety. The joint to be hardened is first faced off, as by means of a grinding wheel. Such facing removes any decarb'onizedv surface film, and reduces the upper surfaces of the rail ends to the same level. The operator then positions the preheater over the joint, in the manner illustrated in Figs. 2 and 3. Preliminary heating is continued until the rail section has attained a predetermined temperature level. preheater covers a. section of the rail which is substantially longer 'than the combined length of the areas on the adjacent rail ends to be hardened.

Assuming that the joint or section being treated has been preheated to a given temperature level. the operator then commences the next operation with the apparatus indicated in Figs. 4 and 5. As the electric arc established between electrode 34 and the upper surface of the rail traverses the area or surface encompassed by box structure 3l',

- it is evident that the layer of metal forming the upper portion of the rail ball, and underlying the is heated to a'relatively practice good results have been secured by continuing the heating by the arc until this upper layer of metal has attained a temperature of about 1500 F.

Following heating by the electric arc, as ex plained above, this apparatus is removedl from the joint, and the apparatus illustrated in Figs. 6 and 7 is placed over the heated area. The operator then causes introduction of oil thru pipe fittings 68 to establish a pool of oil upon the heated areas encompassed by boxes 66. The operations followed during chilling of the rail have been specied and need not be repeated.

At the end of the chilling operation, that is after oil has been removed from boxes 66, considerable heat remains in the adjacent portions of the rail. It has been found that this heat is sufficient to effect tempering of the hardened layer or. layers of metal. Thus to effect tempering, the chilling apparatus is removed fromthe joint being treated, and heat flow permitted to occur back into the chilled and hardened layers of metal. During this tempering or drawing operation, the joint c-an be covered with an asbestos blanket, or other suitable heat insulating means, tov prevent too rapid dissipation of heat to the surrounding atmosphere.

While rails can be hardened without the rst step of preheating, as described herein, preheating is desirable' for several reasons, some of which are as followsz-Preheating tends to avoid shock from the high temperature arc, it tends to minimize stresses or strainsl betweenv the high and low temperature zones, and it facilitates establishment and maintenance of the arc. Furthermore if preheating were not employed, a relatively high rate of heat ilow would occur between the layer of metal heated by the electric arc, and the colder portions of the rail. In other words the relatively cold portions of the rail adjacent'the heated layer of metal would tend to participate in the chilling and hardening operation. By preheating we minimize to a substantial degree, any

' participation in the chilling operation by the It should be noted that the.

the layer of metal being `heated by the are can be more readily brought to a predetermined value, irrespective of climatic conditions, following preheating to a predetermined temperature level .substantially above atmospheric. c

It may be further explained that there is an interrelationship between preheating and drawing. In general the higher the temperature level .to which preheating 1s carried, the greater will be the available drawing after the chilling operation. However the heat for drawing is suppii only in part by preheating, since a certain amount of heat input from the arc is also available for drawing after the chilling operation, particularly since the chilling is accomplished, by contacting only a limited area of the upper surface of the rail with the chilling medium. Under certain conditions, as for example during warm weather,

the method can be carried out without preheating,

but the amount of drawing secured (which will then be by virtue of remaining heat from the arc) will not be as great as is desired for best results. LikewiseY during cold Weather it is possible to carry out the process by an amount of preheating merely suillcient to warm the rail.

It is evident from the above that our method makes possible successive hardening operations under prevailing field conditions, with uniformly that it is somewhat `ure the temperature good results and. to a predetermined hardness pattern, provided the different factors affecting the degree of final hardnessare properly controlled in accordance with'prevailing conditions it has been-found and experience. In practice that with all factors remaining the same, varying degrees of hardness may result due to varying composition of the rails. We therefore prefer to so carry out successive heating and chilling operations as to produce undue hardening of certain rails (e. g. rails having high carbon content) with a hardening of other rails (e. g. rails of lower carbon range desired. The subsequent tempering or drawing operation then brings the hardness of all treated joints within the desired range, because its' softening effect is most pronounced upon metal which has been hardened to a high degree.

With further reference to control,` and particularly with respect tov controlling the heating by the electric arc, it has been previously stated that the electrical input to the arc is preferably maintained substantially constant. We have found difcult to accurately measof the metal to be chilled, under field conditions. Withy our method, the archeating apparatus is preferably kept in operation until a predetermined amount of watthour consumption has taken place, 'and therefore the total heat units imparted to the joint will be the same forl successive operations upon the same rail. `Likewise since the area traversed by the arc isconstant for successive treatments, the mass of metal heated likewise remains constant. With these factors being constant, the same change Y upon said area content) within the hardnessessity of measuring the temperature of the metal ation.

We claim:

1. In a method of treatingv rails to effect hardening of the same, heating a localized area of the upper horizontal surface of the rail ball, causing a stream of 'chilling liquid to be directed upon said heated area, and confining said area so that the liquid from said streamforms a pool upon theI same.

2. In a method for the treatment of rails ta effect hardening of the same, the steps of heating of the rail to be hardened over a localized area o 'the same, causing a stream of chilling liquid to flow upon said area for a predetermined period of time, confining said chilling liquid wherebyA a pool of said liquid is formed from saidstream, and removing liquid from said pool at 'a predetermined rate which will exhaust the pool after a predetermined interval following termination of flow to said the upper surface area.

3. In a method of treating rails to elect hardening of "the same, preheating a portion of the rail, effecting a further heating of a localized area. of the upper horizontal surface of the rail ball within said preheated portion, causing a stream of chilling liquid to be directed upon sad heated area, confining said area so that the liquid from saidy stream forms a pool upon the same, removing the pool of liquid after a predetermined period of' time, and thereafter permitting tempering of the chilled area by flow of residual heat back into said area.

4. In a method of treating rails to effect hardening of the same, heating a localized area of the upper horizontal surface of the rail ball, causing a stream of chilling liquidv to be directed upon said heated area, conningsaid area so that the liquid from said streamforms a pool upon the same, removing the pool of liquid after a predetermined period of time, and thereafter permitting tempering of the chilled area by flow of residual heat back` into said area.

5. In av method of treating railroad rails to -effect hardening of the same, the steps of heating a limited -area of the upper surface of the rail by rapidly traversing an electric arc over the same,

saidv area extendingsubstantially the full width of theA rail ball and for a substantial distance end edges of said area than tothe intermediate portions of the saine, and them-chilling the heated area. y l

6. In a method of treating rails to effect hardening of rail ends, heating-an upper layer of metal in the rail ball, over an area extending for asubstantial Ydistance back from the end of the rail, applying'a stream of chilling liquid to the heated area, and confining the liquid from the stream to afford a liquid blanket of substantial depth upon said area.

RJYAL E. FRICKEY. ARIoN s. KALENBORN.