US2890975A - Method and apparatus for differential quenching of heat treated metallic articles - Google Patents

Description

28903 75 QUENCHING 4 Sheets-Sheet 1 INVENTOR. ML 715/? hhfiom LEA/z H. LENZ OF HEAT TREATED METALLIC ARTICLES June 16, 1959 METHOD AND APPARATUS FOR DIFFERENTIAL Filed April 26, 1955 E AA/M EWA June 16, 1959 w. H. LENZ 2,890,975 METHOD AND APPARATUS FOR DIFFERENTIAL QUENCHING OF HEAT TREATED METALLIC ARTICLES Filed April 26, 1955 4 Sheets-Sheet 2 W/ Mf A k IN VENTOR.

M1727? 6612010 [EA/Z MI? 55 w Arrows June 16, 1959 w. H. LENZ 2,390,975

METHOD AND APPARATUS FOR DIFFERENTIAL QUENCHING OF HEAT TREATED METALLIC ARTICLES 4 Sheets-Sheet 3 Filed April 26, 1955 w mn A TTORNEKS June 16, 1959 w H LENZ 2,899,975

METHOD AND APPARATU FDR DIFFERENTIAL QUENCHING OF HEAT TREATED METALLIC ARTICLES Filed April 26, 1955 4 Sheets-Sheet 4 INVENTOR. ML 727? 544F010 151/2 WA TOHNEYS United States Patent Walter Harold Lenz, Washington, 111., assignor to C ater- ?illar Tractor Co., Peoria, 111., a corporation of Caliornia Application April 26, 1955, Serial No. 503,935

11 Claims. (Cl. 148-2156) This invention relates to zone controlled quenching of heated metallic articles, and more particularly to the provision of a desired hardness pattern in a metallic article by quenching the article with a sheet of quench fluid that has coexisting zones of fluid with different heat abstraction properties.

When a metallic article having a non-circular cross section is heated and then hardened by subjecting it to uniform quenching, the article becomes distorted and it may even develop cracks. A particularly difficult problem is encountered with a severe quench, such as a water quench, which rapidly extracts heat from the metallic articlef As a result, severe quenches have not been employed to any appreciable extent in the quenching of articles that do not have circular cross sections, although such quenches produce a very hard metallurgical structure.

The distortion produced. upon uniformly quenching a metallic article having a non-circular cross section is caused by the difference in the cooling rate of surface portions that are adjacent sections of the article of varying size. When the mass or cross sectional area of a metallic article adjacent a perimeter portion of the cross section is comparatively large, a relatively large amount of heat will be contained in the article adjacent such perimeter portion. Since a uniform quench extracts heat at the same rate from all parts of the article, the surface portions of the article adjacent the thick sections will cool less rapidly than the surface portions adjacent the thin sections which contain the smallest quantity of heat.

Formation of a hard layer of martensite requires rapid cooling of the steel article. Consequently, a thin layer of hard martensite is formed on the thick areas of a metallic article that cools slowly, whereas the thin areas that are rapidly cooled to a greater depth have a relatively thick layer of martensite formed by the quench. The difference in the cooling rate of various parts of the article, and the resultantuneven layer of the hard martensite, which is of lower density than the remainder of the article, produce stresses which result in cracking and distortion. Articles that are of considerable irregularity cause the greatest problem, and the use of a uniform water quench with such articles has been unsatisfactory. As a result, irregularly shaped, elongated articles such as track shoes for tractors are usually made of high carbon steel, and they are quenched by placing the articles in a mild, oil bath quench. However, the hardness layer obtained in an oil bath quench is of uneven thickness, and the resultant stresses are undesirable.

To summarize this invention, it comprises controlling the hardness pattern in a heated metallic article by subjecting the article to a sheet of quench fluid that has coexisting zones of fluid with regulated heat abstraction properties. In this manner the rate of cooling of all portions of a non-circular metallic article can be controlled by abstracting heat more rapidly from thick areas that contain the greatest amount of heat. Best results in reducing distortion resulting from quenching of noncircular articles is obtained in accordance with this invention by subjecting the entire perimeter of a cross section of the article to a scanning sheet of quench fluid, and elfecting relative movement between the article and the quench fluid. The perimeter area of the article is then uniformly hardened progressively as the sheet of quench fluid passes over the surface of the article. However, if desired, the zone controlled sheet of quench fluid may also be employed to produce deliberate distortion or to produce any desired hardness pattern in an article of either circular or non-circular cross section.

The apparatus of this invention for directing a sheet of zone controlled quench fluid onto a heated metallic article has a manifold with an opening of sufiicient size to receive the article, orifice means communicating with the manifold for directing a substantially continuous sheet of quench fluid to said article, and zone control of the heat abstraction properties in the sheet of fluid. The orifice may be either an elongated opening or a series of closely spaced smaller openings which produce the effect of an elongated orifice as long as the sheet is substantially continuous or without cavitation as it strikes the heated metallic article. Control of the heat abstraction propcities in zones of fluid in the sheet is accomplished by varying the volume or temperature of liquid flowing into a zone, or by varying the orifice size in. zones to provide for a different volume of fluid in such zones, or by a combination of such means.

By employing a sheet of quench fluid with the heat abstracting properties controlled in zones, a non-circular or irregular article may be quenched with a severe quench, such as water, to produce a hard surfaced, distortion free article having a substantially uniform hardness pattern. The resultant new article has not been produced by any other method. As previously explained, uniform quenches cause distortion or cracking. Also, quenches directed to portions of an article from different sizes of relatively large, separated nozzles are not continuous or cavitation free unless arranged in accordance with this invention to provide a substantially continuous sheet. Furthermore, a quench that is progressively variable, with the volume either gradually increasing or decreasing along the length of a sheet of quench, can not produce the results of this invention in which separate zones are controlled independently of adjacent zones in the sheet.

For purposes of illustration, the present invention is disclosed in its application to the quenching cycle in the heat-treatment of track shoes of the type commonly employed on track-type tractors, though it will be understood from the following description that the invention is not limited to this particular type of article but is readily adaptable to other fields Where it is desirable to control the hardness pattern in an article.

In the drawings:

Fig. 1 is an isometric view, with parts broken away, schematically illustrating a progression of track shoes in end-to-end abutment propelled by a power conveyor through quenching apparatus embodying the present invention;

Fig. 2 is a vertical transverse section taken through the apparatus parallel to the quench block illustrating the relation of the quench manifold to the shoes;

Fig. 3 is a vertical section through the quench manifold taken substantially along the line III-III of Fig. 2;

Fig. 4 is a view in front elevation of the quench manifold with parts broken away to show the details thereof;

Fig. 5 is an enlarged fragmentary view of the quench manifold in elevation illustrating a modification of the nozzle formation thereof for supplying an increased volume of quench to critical zones of the track shoe;

Fig. 6 is a fragmentary section of the modified nozzle taken substantially along the line VI-VI of Fig.

Fig. 7 is a schematic view illustrating a further rnodification of the invention in which the heat abstraction properties of the quench are controlled by regulating the fluid temperature;

Fig. 8 is a vertical section taken through a track shoe illustrating quench pressures and orifice openings employed for quenching such an article. The numbers closest to the track shoe indicate the size of the orifice opening in inches, and the outer numbers specify gauge pressures of the quenching fluid in pounds per square inch; and

Fig. 9 is a vertical section taken through a quenched track shoe with phantom lines indicating the depth of the hardness layer. The degree of hardness in the Rockwell C scale of various parts of the track shoe appears on the drawing, and reference characters as well as cross hatching have been omitted for clarity.

Fig. 1 discloses the quench apparatus 10 positioned adjacent the discharge opening of a heating element 11, shown herein for the purpose of illustration as an electric furnace. Since the furnace forms no part of this invention, it is to be understood that any of the well-known types of heating elements, such as induction coils, or a gas furnace will function equally as well. A power conveyor 12, driven by a suitable driving arrangement, herein disclosed as a variable speed motor 13, feeds a continuous line of track shoes through the quench apparatus 10 at a preselected rate. The track shoes are preferably fed into the quench apparatus in end-to-end abutment to provide a relatively continuous surface of material passing therethrough.

A quench manifold interposed between spaced rollers 21 of the power conveyor 12 is provided with a suitable opening 22 to permit passage of track shoes therethrough. Quench water is supplied to the manifold 20 through a conduit 23 provided with a thermostatically controlled mixing valve 24 so that quench fluid returned to the manifold 20 through a conduit 26 from an accumulator tank, not shown, may be mixed with a supply of cold water entering said manifold 20 through a line 27, with valve 24 maintaining the quench fluid at a desired temperature.

Quench fluid is directed to the entire perimeter surface of the track shoe as it passes through the quench block. A flexible wiping member 28 secured to a plate 29 is adjustably retained in spaced relation to the quench manifold 20 to remove accumulations of quench fluid which cling to the top surface of the track shoe. This terminates the extraction of heat by the quench fluid within a given longitudinal distance from the quench block, thereby preventing undesirable continued cooling of the track shoe. However, satisfactory results may be obtained without use of wiping member 28 and it is not essential.

In Fig. 2, the manifold 20 is disclosed as comprising a supply tank 31 and a quench block 32 integrated therewith. Heated track shoes 15 are directed therethrough by way of opening 22 as previously described. The shape of the opening 22 is preferably varied to conform to the particular shape of any article to be treated but as herein disclosed, conforms to the general configuration of a single grouser track shoe.

Referring to Figs. 3 and 4, spaced quench directing chambers 33, are formed in quench block 32 and are arranged to generally parallel the shape of the opening 22. As best disclosed in Fig. 3, flow directors 36 integral with cover plates 37 are retained in said chambers 33 in. spaced relation therewith to provide a curved flow path terminating in a reduced elongated orifice or nozzle 38 formed by the edges 41 and 42 of the cover plates 37 and the bottom of chambers 33, respectively, which will direct a scanning sheet of water at an angle to the entire surface of the track shoe progressively .as it moves at a controlled rate therethrough. A plurality of small orifices may be substituted for elongated orifice 38 providing they are small and closely spaced to produce a substantially cavitation free sheet of quench fluid. This modification is readily accomplished by extending the cover plates 37 over orifices 38 and drilling a plurality of small openings. Variations in the size and number of such small orifices may be used to provide an additional zone control over the quench. However, best results are obtained with an elongated orifice which produces a more uniform sheet of quench fluid.

Generally speaking, the plate portion 45 of the track shoe 15 must be substantially flat, and free of distortions to avoid overstressing the shoe during operation. Due to the differences in the rate of heat abstraction of the disproportionate surface and volume variables inherent in an article such as a track shoe, and due also to the unequal rate of volume change resulting from metallurgical transformation during quenching, it has been economically impractical to prevent stress cracking or damaging distortion in certain zones of the plate.

In the present invention, in order to counteract these stresses, quench block 32 is provided with additional spaced chambers 46 and 47 which are divided into subchambers or zones 48 by suitable partitions 49 which extend into directing chambers 33 up to a short distance from orifice 38 for best separation of the zones. In this manner directing chambers 33 are divided into subchambers 50. Each sub-chamber or zone 48 is connected to supply tank 31 as by independent conduits 51. Suitable control valves 52 and pressure gauges 53 are associated with each conduit 51 to permit control of the pressure and volume of quench water supplied to each sub-chamber or zone 48.

Cover plates 37 are secured to block 32 as by capscrews 54. The greater portions of the faces of walls 57 of merging chambers 33 are spaced from cover plate 37 to provide channels 58 as indicated in Figs. 3 and 6 for communication of chambers 46 and 47 with directing chambers 33.

In operation, a continuous supply of quench water is pumped, by means not shown, into supply tank 31 to maintain it constantly under a desired pressure, while the thermostatically controlled mixing valve 24 maintains the quench at a desired temperature. Quench flows into the several zoned chambers 48 at a controlled volume and pressure in each zone as explained. From chambers 48 the fluid passes through the channels 58 and enters the subchambers 50 of directing chambers 33, with the fluid in each chamber having its particular controlled characteristics. The flow director 36 positioned in each cham ber 33 provides a curved path for the flow of water so that it is expelled from the quench block through elongated orifice 38 as an uninterrupted sheet with a minimum of turbulence and with zones of varying pressure and volume throughout its length. The separate zones of fluid automatically merge at their edges so that the change of quench characteristics between zones is not abrupt.

The orifice 38 may be adjusted to vary the volume and pressure of quench fluid by providing slightly elongated or enlarged holes 61 in cover plates 37 so as to permit movement of the plate before the cap screws 54 are tightened.

When conditions require, it may be necessary to further alter the character of quench in areas or zones where the area of the cross section is very large compared tothe surface area, as for instance, in the portion of the track Shoe opposite the grouser. In order that the rate of heat abstraction may be increased in such zones the portion of the nozzle opening directing quench water to these areas may be enlarged as indicated at 62 (see Figs. 5 and 6) to provide an increased flow of quench. If desired, the quench volume may be entirely controlled by mP ying an orifice .of carefully adjusted size in different zones without the use of the partitioned sub-chambers 48 and 50, and independent conduits 51. However, such an apparatus does not have the advantage of the flexible controls shown in the drawing. Variable controls for the heat abstracting properties of zones of quench are important for making adjustments for temperature variations in the steel and for different characteristics of various mill heats of steel.

As described to this point the effect of quench on different zones of the perimeter of an advancing article is controlled by delivering different volumes of quench to the separate zones. A similar effect may be obtained by varying the temperature of quench liquid delivered to the zones. Means for varying the temperature of the quench in different zones is schematically illustrated in Fig. 7. In this figure, a plurality of thermostatically controlled mixing valves 24a are interposed between conduits 26a and 27a to supply quench at selected temperatures through conduits 23a to each of a plurality of supply compartments 31a formed in the supply tank 31 by partitions 31b. Each compartment 31a registers with one of the sub-chambers 48 through its respective conduitSl; thereby providing a continuous sheet of quench with zones of different delivery temperatures. It is also possible to combine the two methods described so that temperatures and volume of quench liquid may both be controlled in zones to obtain a desired hardness pattern.

Thus, substantially distortion free parts are produced by employing a sheet of zone controlled quench that impinges the entire perimeter of a cross-section of the article and passes progressively over the entire article.

In some instances. it is desirable to more accurately define the rearward limit of the quench area and prevent quench fluid from splashing rearwardly outside the quench area. To this end quench block 32 is provided with an air manifold 63 (Fig. 3) having an inlet 64 and a plurality of aligned orifices 66 which are positioned adjacent to the elongated nozzle 38. A supply of air under pressure is directed through orifices 66 to maintain a wall of air adjacent the sheet of water to confine the quench within the area desired.

Due to the fact that the quench clings to the upper, relatively flat surface of the shoe and rapidly falls from the lower surfaces thereof because of gravity, a critical unbalance of internal stresses may exist, and cause distortion. To counteract these stresses, the quench block may be adjusted vertically relative to the plane of moving track shoes by the provision of suitable horizontal slots 67 (Fig. 2), formed in brackets 68 integrated with the quench block 32 and a vertically disposed slot 69 in one of the brackets 71 secured to the side plates 72 of quench apparatus 10.

By increasing the distance between the upper surface of the article and the quench nozzle, and decreasing the distance between the article and the nozzle along the lower surface, said lower surface of the article is impinged by the sheet of quench before its upper counterpart. In this manner the effect of quench falling more rapidly from the lower surface due to the efiect of gravity may be counteracted.

A plurality of manifolds 76 (Figs. 1 and 3) each containing at least one orifice 77, are positioned within the quenching apparatus prior to the quench block 20. As the track shoes are conveyed from the furnace 11 toward the quench block, jets of air or other coolant may be directed to critical areas, such as bolt holes and notches, normally present in articles of this character.

Air under pressure or other suitable quench fluid is directed to each manifold 76 through conduits 78 leading from a pressurized supply header 79. Individual control valves 81 in each conduit 78 permit selective control of pressure to its respective manifold. Thus, stress cracks usually caused by water quenching critical edges surrounding boltholes and notchm in, an article of this type may be avoided by pre-cooling these areas below the critical temperature, prior to quenching.

If desired, the apparatus of this invention may also be employed to produce a uniform scanning quench without use of the zone control features. The flow directors 36 and elongated orifice 38 produce a sheet of quench that impinges the heated metallic article at an angle, and the sheet encircles substantially the entire article. Such an apparatus for progressively quenching an entire article with a uniform quench is useful in many applications in which the cross section of the article is not of great irregularity, or when it is desired to deliberately produce distortion upon quenching.

Although any shape of metallic article can be quenched in accordance with this invention, the greatest usefulness is obtained in the quenching of elongated irregular articles. Such articles become distorted by uniform quenching, as previously explained, and the, problem has been particularly vexing. Even a regularly shaped non-circular article, such as an article with a square cross section, has less heat adjacent the corners than is contained adjacent other portions of the perimeter of its cross section. Thus, uniform quenching of such a square article produces the greatest depth of hard martensite in the corners of the article. This can be remedied by the zone controlled quenching hereof in which a zone of fluid having lower heat abstraction properties is directed at the corners. However, if desired, the zone controlled. sheet of quench fluid may also be employed to produce deliberate distortion or to produce any desired hardness pattern in an article of either circular or non-circular cross section.

The apparatus disclosed is particularly adapted to quench articles that have congruent parallel cross sections. As the article moves past the quench block in a direction normal to parallel, substantially congruent cross sections, the peri-meters of successive cross sections then are subjected to the same effective quenching. If the article is quenched successively along similar cross sections that increase or decrease in size, the depth of the hardness pattern will accordingly decrease ,or increase unless a timed proportional control for the entire sheet of quench fluid is employed.

Any heat treatable steel article may be quenched to provide a desired hardness pattern by the method hereof. Steel articles, particularly those of irregular cross section, that become distorted and cracked when water quenched by other methods, may readily be quenched without distortion or cracking by the method of this invention. If both the carbon content and alloy content of the steel are so high that water quenching renders the hardness layer undesirably brittle and deep, a zone controlled oil quench may readily be employed in accordance with this invention. As is well known in the art, oil is a milder quench and does not produce the degree of hardness that is obtained with a water quench. Also, it is commonly known that when identical steel articles of the same thickness and temperature are quenched with the same type of quench, the degree of hardness is primarily dependent upon the carbon content of the steel, and the depth of hardness depends upon the amount of other alloying compounds, such as manganese. Thus, the type of quench may readily be adapted to the particular steel that is to be employed.

Articles quenched by the zone controlled scanning sheet of this invention are preferably heated uniformly throughout to above the temperature of transformation of the article prior to the quenching. The resultant quenched article hasa tough, ductile center composed of products of transformation, such as martensite, ferrite and pearlite, and an outer hard shell of martensite. If only the surface of the article is heated to above the temperature of transformation for the steel in order to form austenite, which exists only above the temperature of transformation, then the interior of the article will not 7: be as tough and flexible after quenching as when the article is heated uniformly throughout.

After the article has been heated, it is quenched with the described sheet of quench fluid that has zones of controlled heat abstraction properties. It is well known that cold fluid has greater heat abstraction properties than warm fluid. Also, the greater the quantity of the liquid quench, the larger the amount of heat that is abstracted. As previously described, the quantity of quench is readily regulated by controlling either the pressure, or the size of the orifice, or both. The nature of the quench also determines its heat abstraction properties. For example, a water quench extracts heat much more rapidly than an oil quench. Consequently, the foregoing factors are controlled in zones to provide different desired heat abstraction properties in such zones.

A sheet of quench that is free of cavitation, or in other words, substantially continuous along its length of contact with the article, is desirable for avoiding stress producing voids in the quench sheet and in the resultant hardness pattern. One sheet substantially continuous along the upper half of an article, and another sheet substantially continuous along the lower half are generally employed. Also, in order to avoid distort-ion, a sheet of quench fluid is preferably employed that surrounds the article and quenches progressively the perimeters of parallel cross sections of the article. The use of a relatively thin scanning quench that progressively quenches the entire surface of the article, in combination with zone control of the heat abstraction properties in the quench sheet, enables quenching of very irregular articles without substantial distortion, even when a water quench is employed.

The zone controlled quench of this invention is employed to prevent distortion upon quenching articles of irregular cross section by providing a zone of quench fluid with the greatest heat abstraction properites for quenching the thickest portions of the article, since these portions contain the greatest quantity of heat. Zones of quench fluid of proportionally less heat abstraction properties are employed for the portions of the article that have smaller masses per unit of surface area, and which as a result contain less heat.

The final adjustments for providing a suitable balance of heat abstraction properties in the various zones of quench fluid are readily made by observing the distortion produced in the article upon quenching. The proportional heat abstraction properties of zones of fluid contacting portions of the article in which concave distortion was initially produced is increased to remedy such distortion, and the proportional heat abstracting properties are decreased in areas that have convex distortion. The distortion may be observed by comparin the quenched article with the original unquenched article, or by merely placing a straight edge along linear portions of the article. The. hard martensite layer produced by the quench is less dense than the remainder of the article. Therefore, when the martensite layer is not of uniform thickness, the resultant distortion is apparent and it may be corrected by accordingly adjusting the heat abstraction properties in the zones of quench fluid. In this manner, a substantially uniform hardness pattern may readily be produced in the article by adjusting the zones of quench fluid until the quench cools all surface portions of the article at approximately the same rate and to the same depth. Upon cutting a cross section through the quenched metal, the depth of the hardness layer is visually apparent because its color is lighter than the interior of the metal article.

When an irregularly shaped article is heated throughout and quenched by the method of this invention, 'a substantially uniform depth and degree of hardness is obtained in the article, and a tough inner core is formed that contains products of transformation, such as pearlite, ferrite, and martensite. The hardness layer is composed primarily of martensite, and the degree of hardness grad ually decreases towards the inner edge of the layer. As illustrated in Fig. 9, there is an abrupt decrease in hardness at the inner boundary of the hardness layer, and the inner core of the article is relatively soft and ductile. The chemical compositon of the article hereof remains the same throughout, although the metallurgical state is changed by the quenching.

If an irregular article is quenched by a uniform quench, such as by plunging it into a quench bath, an uneven hardness pattern is produced. Furthermore, although the well known carburizing method of hardening, which is expensive and time consuming, produces a uniform hardness pattern, the resultant carburized article is different from the article of this invention in other respects, such as in the decrease of carbon content towards the interior of the article. Consequently, the irregular elongated article of this invention having a series of congruent parallel cross sections along a substantial portion of its length, a uniform chemical composition, and which has been quenched to produce a substantially uniform hardness pattern, is a new and distinct article.

After the article has been quenched, it may be tempered as desired. The selective tempering disclosed in United States Patent No. 2,549,930 is particularly useful for use in tempering articles produced in accordance with this invention.

The following is a specific example of the use of the zone controlled quench of this invention as applied to the quenching of a track shoe for a track-type tractor.

A track shoe having a configuration of the shoe in Figs. 8 and 9 are quenched by the zone controlled scanning quench hereof. The track shoe was made from steel of S.A.E. specification #1039. In addition to iron, the steel contained the following percent by weight of other compounds: Carbon 0.36%, manganese 0.80%; sulfur 0.19%; phosphorus 0.031%; silicon 0.21%; nickel 0.05%; chromium 0.05%; molybdenum 0.02%, and copper 0.05%. The length of the track shoe is 24 inches, the width is 9 inches, the thickness of the plate portion inch, and the height of the grouser tip above the plate portion is 2 inches. A one foot length of the track shoe weighs 25.21 pounds.

The track shoe was heated throughout to a temperature of approximately 1550" F. in a furnace. As the track shoe was conveyed to the quench block on apparatus of the type illustrated in Fig. 1, the temperature dropped and it was about 1500 F. at the time of quenching. The rate of movement of the track shoe was 2.27 feet per minute.

The track shoe was then subjected to a water quench of a uniform temperature of about F. The size and location of the orifice openings are given in Fig. 8. Also, the pressure employed in pounds per square inch gauge pressure, and the zones of such pressures are specitied in Fig. 8. The total volume of quench employed was gallons per minute.

The resultant hardness pattern of the track shoe is given in the Rockwell C scale in Fig. 9. The phantom line on the interior of the track shoe in Fig. 9 illustrates the depth of the hardness pattern and the degree of hardness. It is apparent that the depth is substantially uniform. The hardness of the outer surface of the article is 59 to 61 on the Rockwell C scale. This hardness decreases slowly toward the inner part of the martensite layer. An abrupt change of hardness occurs at the inner port-ion of the hard martensite layer, and the interior of the article is relatively soft. The resultant article is substantially free of distortion.

I claim:

1. A quenching apparatus for directing fluid to a heated metallic article, which apparatus comprises a manifold with an opening of suificient size to receive the article, means for supplying into said manifold a quench fluid which is of the same kind throughout, orifice means communicating with said manifold for directing a substantially continuous cavitation free sheet of said fluid at an acute angle against the entire perimeter surface of a cross section of the article, means for controlling the heat abstraction properties of zones of fluid in said sheet substantially, independently of the heat abstraction properties of adjacent zones, and means for providing relative movement between said metallic article andsaid manifold whereby said sheet of fluid passes progressively over the entire surface of said article.

2. An apparatus for directing quench liquid to a heated article of irregular cross section while the article is in motion at acontrolled speed which comprises a manifold with an opening through which the article may pass, means for supplying into said manifold a quench liquid which is of the same kind throughout, an elongated orifice for directing a substantially continuous sheet of said liquid against the perimeter surface of a cross section of the article, separated chambers within the manifold communicating with said orifice, and means for directing said liquid at difl'erent pressures to said chambers to produce a sheet of liquid through the orifice with zones of diflerent delivery volume.

3. An apparatus for directing quench liquid to a heated article of irregular cross section while the article is in motion at a controlled speed which comprises a manifold with an opening through which the article may pass, means for supplying into said manifold a quench liquid which is of the same kind throughout, an elongated orifice for directing a substantially continuous sheet of said liquid against the perimeter surface of a cross sectionof the article, separated chambers within the manifold communicating with said orifice, and means for directing said liquid at different temperatures to said chambers to produce a sheet of liquid through the orifice with zones of different delivery temperature.

4. The method of controlling the hardness pattern developed in a heated metallic article upon quenching thereof which comprises subjecting said article to a substantially continuous sheet of the same quench fluid throughout such sheet and which has coexisting zones of said fluid with diiferent heat abstraction properties that are substantially independent of the heat abstraction properties of said fluid within adjacent zones in said sheet; and efliecting relative movement between said article and said sheet of quench fluid.

5. The method of controlling the hardness pattern developed in a heated metallic article upon quenching thereof which comprises subjecting said article to a substantially continuous sheet of the same quench fluid throughout said sheet and which has coexisting zones with different controlled quantities of said fluid in said sheet, the quantity of said fluid within a zone being substantially constant throughout each zone, and being independent of the quantity of fluid within an adjacent zone in said sheet; and effecting relative movement between said article and said sheet of quench fluid.

6. The method of controlling the hardness pattern developed in a heated metallic article upon quenching thereof which comprises subjecting said article to a substantially continuous sheet of the same quench fluid throughout said sheet and which has coexisting zones of said fluid with diflerent controlled temperatures in said sheet, the temperature of said fluid within a zone being substantially constant throughout the zone and being independent of the temperature of fluid within an adjacent zone in said sheet, and eifecting relative movement between said article and said sheet of quench fluid.

7. The method of controlling the hardness pattern developed upon quenching a uniformly heated, elongated metallic article having parallel cross sections of similar shape, which comprises subjecting the substantially entire perimeter of such a parallel cross section in said article to a continuous sheet of the same quench fluid throughout said sheetand which has coexisting zones of said fluid with different heat abstraction properties, said zones of fluid in the sheet being blended at their adjacent edges to prevent cavitation; and effecting relative movement between said article and said sheet of quench fluid so that said sheet advances over substantially the entire surface of said metallic article hardening successive perimeters of said similar cross sections.

8. The method of obtaining a substantially uniform hardness pattern upon quenching a heated metallic article having parallel, congruent, non-circular cross sections whereby different quantities of heat are contained in the section of the article adjacent different perimeter portions of such cross sections, which comprises providing a continuous sheet of the same quench fluid throughout said sheet and which has coexisting zones with different heat abstraction properties for contacting substantially the entire perimeter of such a cross section, adjusting the heat abstraction properties of the zones of said quench fluid to correspond proportionally to the quantity of heat contained adjacent said perimeter portions of such cross sections, subjecting said metallic article to said sheet of quench fluid while maintaining the zones of quench fluid with greatest heat abstraction properties in contact with the cross section perimeter portions that are adjacent sections of the metallic article containing the greatest quantity of heat, and eifectin-g relative movement between said article and said sheet of quench fluid in a direction substantially normal to said parallel cross sections so that said sheet progressively advances over substantially the entire surface of said metallic article hardening successive perirneters of said cross sections of such metallic article.

9. The method of uniformly hardening an elongated steel article having irregular, parallel, congruent cross sections which comprises heating said article to above its temperature of transformation; providing a substantially continuous sheet of quench water that is substantially without cavitation and which has coexisting zones with different quantities of said water in said zones, adjusting the quantity of said water in said zones to correspond proportionally to the quantity of heat contained in said steel article adjacent perimeter portions of such irregular cross sections, subjecting said steel article to said sheet of water while maintaining the zones of quench water with the greatest quantities of water in contact with the perimeter portions of said cross sections that are adjacent the greatest quantities of heat in said article, and effecting relative movement between said article and said sheet of quench water so that said sheet advances progressively over substantially the entire surface of said steel article.

10. In the quenching of a uniformly heated metallic article of irregular, parallel, congruent cross sections by passing over the surface of said article a continuous sheet of the same quench fluid throughout said sheet and having coexisting zones of said fluid with controllable heat abstraction properties, the method of correcting distortion of said article produced upon quenching which comprises increasing the proportional heat abstraction properties of zones of fluidl contacting portions of said article in which concave distortion was initially produced, and decreasing the proportional heat abstraction properties of zones of fluid. contacting portions of said article in which convex distortion was initially produced.

11. A quenching apparatus for directing quenching fluid to a heated metallic article, which apparatus comprises a manifold with an opening of sufiicient size to receive the article, means for supplying into said manifold a quench fluid which is of the same kind throughout, orifice means communicating with said manifold for directing a substantially continuous cavitation free sheet of said fluid, means providing different quantities of said fluid in distinct zones of said sheet and providing a sub stantially uniform quantity of fluid throughout each of said zones, and means for providing relative movement between said metallic article and said manifold whereby said sheet of fluid passes progressively over the entire surface of said article.

References Cited in the file of this patent UNITED STATES PATENTS 12 Denneen et 21. Dec. 16, 1941 Somes Sept. 8, 1942. Somes Mar. 2, 1943 Somes Mar. 12, 1946 Arnoldy Oct. '14, 1947 Riegel et al. Sept. 4, 1951 Secor Nov. 4, 1952 Linney June 22, 1954 Lyon Dec. 6, 1955 FOREIGN PATENTS Switzerland Feb. 16, 1939 Great Britain Mar. 15, 1949

Claims (1)

1. 4. THE METHOD OF CONTROLLING THE HARDNESS PATTERN DEVELOPED IN A HEATED METALLIC ARTICLE UPON QUENCHING THEREOF WHICH COMPRISES SUBJECTING SAID ARTICLE TO A SUBSTANTIALLY CONTINUOUS SHEET OF THE SAME QUENCH FLUID THROUGHOUT SUCH SHEET AND WHICH HAS COEXISTING ZONES OF SAID FLUID WITH DIFFERENT HEAT ABSTRACTION PROPERTIES THAT ARE SUBSTANTIALLY INDEPENDENT OF THE HEAT ABSTRACTION PROPERTIES OF SAID FLUID WITHIN ADJACENT ZONES IN SAID SHEET; AND EFFECTING RELATIVE MOVEMENT BETWEEN SAID ARTICLE AND SAID SHEET OF QUENCH FLUID.

Images