US1730918A - Tempering apparatus - Google Patents

Description

Patented @et 8, 1929 JAMES CAREY DAVIS, F CHICAGO, ILLINOIS TEMPERING APPARATUS v Application filed November lily present invention relates to the art ot tempering in general, more particularly to the tempering of metal and epecilically to 'the localized. hardening oi" steel castings containing' a modifying agent Broadly considered, the invention comprehends an improved method for tempering an aimaratue tor carrying out the tempering' method and the resiihzantl improved product.

ilhile e invention has a broad iield of ueeifilnc ,tor changing the state ot Various article@` of different composition, l have tound it ot peculiar utility tor producing east steel ear wheels containing manganeseaa a modifue' agent7 and I therefore lind it convenient to describe the'invention in connection with auch product; it being understood that such llimited .fieldeI oi specific description are emploj'd purely tor purposes Ot' an example Le utility of the invention in its Several phases. f

ifhe principal objects oi the present invention are the provision of an improved method et temiiering, the provieion et an in'iproved apparatus t'or tempering, the provision oi' an inmrored tempered product; the provision ot e method eftempering characterized by a localization oi the tempering; the provieion ot' a method of tempering wherein the area of the tempering may be substantially controlled within predetermined limits; the provision of a method ot te npering characterized hy the direction oit fluid upon predetfzrmined pointe' until all the article be tempered and I a c lization of the tempering; the

provision ot' a method of tempering characterized by a differential or progressive temperingoifthe article gthe provision of a method ot tempering characterized by the employment o't means to prevent theaction by one treated l art upon another part of 'the article it ie deaired to temper; the provision. ot a method ot tempering characterized by So treating the surfaces ri'ing' out the Steps y t; n parte ofAx the articles upon which the open ation ie performed as to produce diiierential qualities; therein; the provision of a method f oit temp-eri j characterized hy the direction et' the treating fluid upon the article to be 1, ieee.

may be tempered characterizedby localized areas and then treating other areas to be tempered and car-y ot tempering with cer- Serial N'o. 145,509.

tempered in general, and in paiticular means 'for directing such fiuid upon the precise area to be acted upon; the provision of a method oil", tempering characterized by the employment ot a plurality ot streams of different volume or intensity, combined with means tor controlling the tempering characteristic et the metal whereby areas oit the article may be tempered differentially; the provision ci a method ot tempering characterized by the employment oft an ununit'orm quantity of tempering fluid whereby areas of the article differentially; the provision et a method of tempering characterized by the etepe of initially treating localized areas and subsequently treating the article whereby areas thereof may be differentially tempered; the provision of a method of ten periug characterized by initially treating one portion and subsequently tempering other portions including Said first portion without affecting the first portiontreated; the provision ot a method ot tempering whereby localized areas are initially treated and then other areas treated together with said first mentioned yareas, whereby differential qualitice may be obtained by a single treatment; the proiisionoi a method for the heat treatment o't'mctal, whereby localized areas are treated and then subsequently utilizing the heat of the main body oi the article for varying' the property of the areas initially treated so that the areas first treated will be ot setter character than the other areas; the provieion'of a rtempering method whereby localized areas are Succcesively treated, wherein the first treated area is of softer character than the subsequently treated areaa; the provision of a tempering method changing the character Ot' with said localized areas to produce a dit'- f'erentially hardened effect in which the subsequently treated areas are harder than the initially treated localized areas.

The invention also has for its further 0bject the provision of a temperingapparatus including means for localizing the tempering/action upon the article which it is desired to change; the `provision 0f a temper- 100 Cil ing apparatus characterized by the horizontal ejectionrot' tempering fluid so that parts may remain unmodified; the provision tempering apparatus characterized by the einployinent of a plurality of streans olf tempering fluid whereby dierential tenipering may be imparted to an article; the provision of a tempering ayjfparatus characterized by the einployinent oi treating ineans for articles to be tempered, and in the further provision olineans for l ing tempering liuid'upon other areas oi arti e; the Vprovision oi tenipei" ig ratus including ineans Jroi' projecting; teinpering' iiuids upon localized areas and in cluding inea-ns tor tempering` other areas; and the provision of iinproved nieans for carrying' out the aforementioned processes.

ln the attainment of the tor-enjoin@ jects and certain additional benet and advantages to be herein disclosed, convenient to carry out iny rnethod by means ora an apparatus, the einbodinients o which are illustrated 'n the accompanying drawing'. On inspection ot this drawing', it will be observed that as above suggested? I have for purposes of convenience 'in disclosure and description illustrated apparatus in forni adapted Jfor the treatment of a disc-like metallic casting7 to wit: in the present case. a iianged cast manganessteel wheel of a carbon content of. .32% to .38%.

The invention is peculiarly adapted for the treatment of such objects as will be manifest when it is considered that a great desideratuna in the hardening ot wl el treads is that such hardening be unit-erin in' order that the wheel may wear both uniorrnly in service and not lose its circular character and t the saine time th i hardening' be localized to that portion ot the tread and throat which is most usual in contact with the rail head in order tl i the riin of the wheel inay wear uniformly and not becoine curved in cross-section in service.

To this end, therefore, it is most desirable that the outer surface ot the naneje ot the wheel which orcinarily is 4quite or" suiiicient hardness Without tempering. be not further hardened Aand similarly. that the outer marginal portion or heel ol the tread which is opposite to the liange receives much less wear owing to its rel vely less Contact with the Vrail head be lett less inedifiefl and relatively soft, so that the wheel and tread in service will wear down uni fornily.

It is likewise desirable that the web ot the center of the wheel be le'it tree from hardening and in its normal relatively soit state.

In my application. Serial No. 674.485 l have described a method and apparatus toi' obtaining a differentially hardened tread surface by shielding portions or said tread against the action ot the tempering` fluid. Vllhough this process has certain advantages outlined in the application aforementioned, it has been l'ound that aside troni the neces sity or" the use of inovingl partis of the agpz. tus descrised and the necessity `for manually or otherwise applying this shield to the article to be tempered, that the desired shielding ehect is not obtained to the degree desired due to conduction of heat to roi the article treated vfitn which the shield inust corne into Contact, or by reason oi' the tempering; lluid finding' its wa'v to the article past the iiroteciin i` shield.

lhe word tempering as employed heren, relates to changing' the state or. the inetal rested. that is it may apply to either harding or softeningor changing' lbe relati *c tate or condition et various portions oi a single casting' as will r-.pnear the example illustrated and described being; for the purof producing; a castingr or various 'ees of hardening in a particular region ereot. ln' the accoinpanyingr drawing, Fie'. l is a side elevation taken in section of one torni of niv teinperir apparatus;

l" 2 a Ytragrnentarv view similar to l, showingF the treatment of another portion o an article;

Fig. 3 is a side elevation talren in section an apparatus for projecting' tempering an article;

is a iraginentr-iry view of the apparatus shown in. Fig. l'or treating an article different position; M

.is a further embodiment of the apparatus shown in Fifi.

c (i is a fragmentary view or the api-Lian. tus shown in Fig'. 5 with the article in the reverse position;

lling. 4" is a transverse sectional vieiv oit the wheel tread;

Fig. 8 is a carbon iron diagram shoving;r the variation in temperatures and the state ot the carbon.

ln order to obtain steel wheel having a erentially ternp d tread portion. l ina v suhiect localized potions ol the tread c riin `oi' wheel cac i o' which is still above the critical i to partially vmj action for a short period of' time; iny preferred einbodinient where a wheel is to be te. ered. the heel porot the tread is treated with a teniperinoj has reached a substantially below the critical i temperature range.

l have 'found that in the ordinary torni of cil-st wheel. the heel portion will reach this Midition in about troni l0 to l5 seconds.

r this initial treatment. the casting is troni the influence ot the tempering removed.

y the soft portions fluid for a period of time sufficient to permit the heat of the main body of the casting to reheat the initial portion treated. Preferably this reheating is attained'by conductionfrom the main body of the casting to the portion initially treated.

I have found that sufficient the initially treated re-heating of portion is' obtained by the casting' such as is herein preferably dealt with, in a period of about 30 seconds, and that this period of time is suflicient to overcome any structural changes which may have talfen place at the initial quenching to render the heel portion unduly hard.

After air exposure or after the second step permitting the transference of yheat by conduction from the main body of the casting to the portion initially quenched, the entire tread surface ofthe casting is then given a quenching treatment, rendering the inner surface of the flange, throat, and tread por tions extremely hard, whereas the heel por-- tion first treated will be found to be of such softness as will give best. operatingl results in the preferred use herein described. The effect is similar to that produced by quenching at lower temperatures. n I have found that quenching" .from 4. to 4% minutes is sufficient to impart the desired hardness to the flange and tread areas and a softer effect is obtained at the heel portions or the portions which have been given .initial quenching action.y

For purposes of carrying out the proces above described, I have found the apparatus shown in Fig. 1 to admirably serve the purpose. i

Referring to Fig. 1, I have there illustrated a quenchimY apparatus which I have found to be particularly `suitable for treating car wheels and as therein shown 1() is a pan having an annular depression, 11, defined by the upstanding walls 12 and 13 an intermediate pedestal 14 arranged concentrically with the upstanding walls 12 and 13. or supplying quenching fluid to this pan,`I provide fluid conduits 15, 16. 17 and 1S arranged on either side of the annular grooves defined by the pedestal 14. There is also provided an overflow outlet 19 which may be located to give any desired depth of overflow. The process is practised preferably as follows 1-T he casting, for example a car wheel, is treated while at a temperature which is above the critical range in a manner such as will be recognized to be thebest practise in suchl cases, depending upon the chemical composition of the steel that is used. For giving the wheel the'initial treatment, the quenching' bath may first be prepared so as to have a constant level of quenching fluid. The wheel is then placed into the quenching pan, so that. it rests upon the pedestal 14 exposing' that portion desired. to be treated to the quenching fluid, and in one embodiment of lng fluid, I have found that a and having f ycasing of the same general form as the my invention the heel portion 21 is first immersed into the quenching bath. As has been previously described, the wheel is left in t-he quenching bath for a period of 10 to 15 seconds, where y water is used as a quenching fluid.

Though I i have described my preferred method of operation as carried out in conn stantlevel quenching bath, I may first position the casting upon the pedestal 14 and then ygraduallv supply the quenching fluid for serving the initial quenching operation. This method of quenching will have the function which will be apparent as the discussion proceeds.

After this initial treatment the casting is removed from the influence of the quenching fluid to permit the re-heating of the heel portion 21 by conduction of the heat of the body of the casting which in practice I find is ac- Coinplished satisfactorily in about 30 seconds as is above described. Thereupon, the combined areas forming the initially treated heel portion 21 and the tread surface 22 is quenched, and where I use water as a quenchperiod of from 4 to 41/2 minutes will give excellent results.

Theprocess above outlined may be either for initially treating the heel portion 21, or if desired, I may initially treat the flange portion 23 as shown in Fig. 2.

In this way, by a single heating of the casting, the 'separate parts may be quenched by a series of steps, the length of time necessary for carrying out the steps being sufficient to permit that change in temperature which will obtain best results upon subsequent quenching action. i

In Fig. 3, I have illustrated a quenching bath for treating the combined areas of the wheel treated initially as above described, and this apparatus is preferably of anature described in my application Serial No4 670,486 in `which 24 is a casing adapted to' receive quenching fluid from the inlet 25 and having a plurality of series of nozzles 26, 27 and 28 for projecting the quenching fluid, all this' preferably in accordance with the apparatus described in my application aforementioned.

In Fig. 4, I have illustrated the apparatus above described in Fig. 3, but shown with the wheel in a reverse position, so that the flange 23 is downwardly directed and the heel portion 21 is upwardly directed, thereby permitting the quenching fluid to gravitate away from the heel portion 21 downwardly upon the flange portion 23.

InF ig. 5, there is illustrated a further embodiment of my invention in which 29 is a casing above described and in my prior application previously mentioned.'` This casing is divided preferably.horizontally by the partition wall 30 forming an upper chamber 31 and a lower chamber 32.' These chambers are adapted to have separate quenching fluids fed from independent feeding means or conduits not shown in the drawing. The Vupper chamber 3l has a plurality of series of nozzles 33, 3f 85 similar to those shown in the embodiments illustrated in Figs. 3 and Il. VThe lower chamber 35 has a series of nozzles 36. By this form of apparatus, the process may be carried out as follows The casting vis taken up at the accustomed temperature for tempering and is then introduced within the confines of the tempering device 29, care being taken by vsuitable means to have it concentrically positioned with the general aXis of the apparatus. rlhe initial localized ytreatment is then given Vto the casting by means of a series of jets 36,the tempering fluid bei-ng directed against the heel portion 3l in the instance where the casting is positioned with the heel portion downw rdly directed as shown in Fig. 5.

Upon the application ofthe tempering fluid 36 for a period of time, as above described, the flow of the liquid is discontinued for a period sufficient to permit re-heating of the initially localized area that has been treated, that is to say, to permit re-heating by conduction. Subsequently, upon the expiration of the period necessary to produce this effect,the jets 33, 34: and 35 are turned on to direct the quenching liquid upon the `entire tread surface, or all the jets 33, 34, 35 and 36 may be turned on to have the combined tread surface 22 and heel portion 2l submitted to the quenching action.

The series of jets 33, 34, 35 and 36 are pref erably arranged as in my application aforementioned so that the uppermost jet supplies a larger `quantity of quenching fluid than the lowermost series of jets. ln this way if desired the lcontinuous surface exposed will be affected by a uniform amount o quenching fluid.

In the embodiment shown in 6 the casting may occupy a reverse position so that the flange portion Q3 is downwardly directed and is first subjected to the initial treatment by the lowermost series of jets 36.

In Fig. 7 there is illustrated a section of the periphery of the cast wheel showing the effect of the differential tempering action in terms of the Brinell hardness scale. Thus, it will be observed that those portions of the tread surface which are required to be toughest indicate the lower figures while those portions which receive the greatest wear have the higher figures. These may be made gradient from the outermost portion receiving the greatest shock to the innermost portionwhich is apt to receive the greatest wear' in accordance with practice which will be obvious to those skilled in the art. By thus grading the hardness in accordance with the treatment above out-lined, uniform wear will be had in use to retain perfect yroundness of the wheel contour throughout all of the tread surface.

ln Fig. 8 there is shown a carbon-iron diagram, the curves on which indicate the transitions of carbon in steel when subjected to heat, followed by cooling. The upper divergence of the curve, as laid upon the scale, indicates the approximate temperature at which the carbon content of the steel goes into solution with the iron. The lower divergence of the curve indicates upon the scale the approximate temperature at which the carbon goes out of solution with the iron, at which time pcarlite is formed.

is at a temperature above the upper critical point, since in the application of a quenching medium, after the temperature has fallen below the lower critical point and the carbon has gone out of solution, only a comparatively y When steel slight hardening action results. has been heated to a temperature above the up per critical point and is then subjected to the action ofa quenching medium, a very substantial increase in the hardness of the steel is established and it remains in such state until the re-application of sufficient heat to modify the sai-d hardness. The critical points of steel are modified by variations in the chemical constitution of the steel, and therefore the curves on the carbon-iron diagram show relate to a special composition of steel which l have found best suited to the production of the articles herein mentioned.

lt is readily understood that the results obtained by me in producing a car wheel casting having a tread surface of harder characteristics than the localized initially treated surfaces having softer areas,-that is the heel portion or the outer tread portion,-can be and are ascribed tothe fact that the heel or rim portion has been quenched at a temperature above the pper critical point, and would be as hard as the center of the tread portion were it not for the fact that the application of the quenching medium is of such short duration that the main body of the casting is not affected thereby, with the result that upon cessation of application of the quenching medium to said heel portion of the tread th is a substantial reheating or return of l by conduction to the said heel portion wher eby the hardness thereof is substantially modified, even though the said reheating or turn of heat increases the temperature of the heel portion to exceed the lower critical point as indicated on the diagram. The subsequent application of a substantial volume of water to the main tread portion of the wheel causes great hardness thereof, but previously to this application the heel portion has been brought below the thermal point at which the further application of water would confer great hardness.

` The result of following the various steps lt isfknown practice to quench steel to obtain hardness while the steel x of the procedure herein indicated is that I produce an integral car Wheel Whose main tread or Wearing surface is of great hardness, and at the same time the heel or outside of tread portion of the rim is softer and more ductile, thereby establishingT a car Wheel structure Which is much stronger under impact and which Will Wear more evenly in the regular service Which it performs, than otherwise would be the case. y

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent, is:

l. A tempering apparatus comprising in combination a source of tempering fluid, means for supporting a casting to be tempered on its side and means for applying the tempering fluid to the periphery including means for limiting the range of application of the tempering fluid from said last named means to the edges of the peripheral surface of the casting.

2. A tempering apparatus for car Wheels comprising in combination a source of tempering fluid, means for directing a plurality of strean'is of fluid from such source upon the periphery of the car wheel to be tempered,

said strean'is being' operable independently of f keach ether to effect gradient tempering by application of independently controlled streams of tempering fluid.

Atempering apparatus for car Wheels or the like comprising in combination a source of tempering fluid.v means for directing` a stream of fluid from such source upon the peripheral portion of the article to be tempered, said means having independent means of controlling the flow of fluid to direct gradient quantities of such tempering fluid to the periphery whereby an edge portion of said peripheral portion may be independently' treated.

et. In a tempering apparatus adapted to temper a car wheel casting, means for directf in a tempering fluid in a plurality of streams to the periphery thereof comprising independent chambers, one of said chambers including means for directing a plurality yof series of streams.

5. In a tempering apparatus adapted to temper a car Wheel casting, lying on its side, means for directing a tempering fluid to independent portions of the periphery thereof comprising independent chambers, one of said chambers including means for direct-ing a plurality of series of streams arranged one above the other. f

G. In a tempering apparatus adapted to temper a car Wheel casting, lying on itsside, means for directing a tempering fluid to independent portions of the periphery thereof, from independent sources comprising independent chambers, one of said chambers including means for directing a plurality of streams arranged one above the other, the uping the application riphery of said car permost series having' the largest volume of streams.y y

7. A tempering apparatus for car Wheels comprising in combination a source of tempering fluid, means for directing a tempering fluidto the peripheral portion of the car Wheels and means for directing and limitof the tempering fluid to outer edges of the peripheral portion foil tempering the peripheral portions with different intensity to other portions of the periphery.

8. A tempering apparatus for car Wheels comprising in combination means for directing a'plurality of streams of fluid to thepe- Wheel including means to direct and independently limit With different intensity the application of the tempering fluid to outer edges of said periphery.

9. A tempering apparatus for car Wheels comprising in combination means for directing a tempering lfluid in independent streams to different portions of the periphery of the car Wheel, tempering fluid, one of which being arranged for directing the tempering fluid to an outer edge ol the periphery for tempering the periphery of said casting with different intensity.

l0. A tempering apparatus for car Wheels comprising in combination means for directing a tempering fluid in independent streams to different portions of the periphery of the car WheelA independent chambers for said tempering fluid, one of which being arranged for directing the tempering fluid to an outer edge of the periphery of' said casting, the other of said chambers being provided with means to independently direct the tempering fluid to inner portions of said periphery of said casting whereby temperingof different intensity of the entire periphery may be obtained.

In testimony whereof, I have hereunto signed my name this 29th day of October,

JAMES CAREY DAVIS.

independent chambers for said

Images