US3686949A

US3686949A - Sampling devices and powder diffusion containers for use with molten metal

Info

Publication number: US3686949A
Application number: US12751A
Authority: US
Inventors: Robert J Hackett
Original assignee: Haly Inc
Current assignee: Haly Inc
Priority date: 1970-02-19
Filing date: 1970-02-19
Publication date: 1972-08-29
Anticipated expiration: 1989-08-29

Abstract

Molten metal samplers adapted for convenient and speedy withdrawal of metal samples from a body of molten metal in a basic oxygen furnace, a Bessemer converter, an electric furnace or the like, these samplers being capable of producing nonporous, solidified metal samples indicating the composition of the melt and having separate sample portions of radically differing dimensions suitable for metallurgical analysis by different techniques, such as spectroscopy, microscopic analysis and the like. Means are provided for ''''killing'''' the oxygen present in the ''''unkilled'''' steel melt in a basic oxygen furnace automatically during the taking of the sample, and cooperating chill block means and vent means are provided to facilitate the chilling and solidification of adjacent portions of the sample having radically differing diameters during and immediately following the sample-withdrawal operation. A thin tubular paper diffusion container filled with finely powdered magnesium is positioned inside the metal sampler, and forms a highly effective ''''killing'''' means for ''''wild'''', high oxygen-content unkilled steel melts. Diffusion containers of this kind also provide an effective means of diffusing a constituent or alloying powdered material throughout a body of molten metal.

Description

United States Patent Hackett 1 Aug. 29, 1972 [54] SAMPLING DEVICES AND POWDER DIFFUSION CONTAINERS FOR USE WITH MOLTEN METAL [72] Inventor: Robert J. Hackett, c/o Haly Inc., Cross Rd., Brookfield, Conn. 06804 [22] Filed: Feb. 19, 1970 [21] Appl. No.: 12,751

Related US. Application Data [63] Continuation-impart of Ser. No. 830,740,

FOREIGN PATENTS OR APPLICATIONS 1,526,144 10/1967 France ..73/42l UX Primary Examiner-Louis R. Prince Assistant Examiner-Denis E. Corr Attorney-Robert I-I. Ware ABSTRACT Molten metal samplers adapted for convenient and speedy withdrawal of metal samples from a body of molten metal in a basic oxygen furnace, a Bessemer converter, an electric furnace or the like, these samplers being capable of producing non-porous, solidified metal samples indicating the composition of the melt and having separate sample portions of radically differing dimensions suitable for metallurgical analysis by different techniques, such as spectroscopy, microscopic analysis and the like. Means are provided for killing the oxygen present in the unkilled steel melt in a basic oxygen furnace automatically during the taking of the sample, and cooperating chill block means and vent means are provided to facilitate the chilling and solidification of adjacent portions of the sample having radically differing diameters during and immediately following the sample-withdrawal operation.

A thin tubular paper difiusion container filled with finely powdered magnesium is positioned inside the metal sampler, and forms a highly effective killing means for wild, high oxygen-content unkilled steel melts. Diffusion containers of this kind also provide an effective means of diffusing a constituent or alloying powdered material throughout a body of molten metal.

18 Claims, 23 Drawing Figures Patented Aug. 29, 1972 3,686,949

4 Sheets-Sheet 1 1202102 [fi/ddrdf 1 NVEN TOR.

m/A/M Patented Aug. 29, 1972 4 Sheets-Sheet 2 INVENTOR.

Patented Aug. 29, 1972 3,686,949

4 Sheets-Sheet 5 2016 6H J flat/Yd! INVENTOR.

A A/m SAMPLING DEVICES AND POWDER DIFFUSION CONTAINERS FOR USE WITH MOLTEN METAL CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation in part of my copending application Ser. No. 830,740 filed June 5, 1969, now abandoned.

This invention relates to the field of metal sampling, and more particularly to methods and apparatus for the withdrawal of representative metal samples from a body of molten metal in a basic oxygen furnace, a Bessemer converter or other types of furnaces. Samples of molten metal solidified in solids, non-porous bodies having portions of radically different diameters suitable for the performance thereon of different kinds of cast or metallographic analysis to determine the composition and the percentages of impurities present in the metal.

BACKGROUND OF THE INVENTION The necessity for withdrawing metal samples from bodies of molten metal in open hearth furnaces, blast furnaces, electric furnaces, basic oxygen furnaces and Bessemer converters in order to monitor the composition and characteristics of the melt has presented a serious challenge to metallurgists for many years. Slag floating on top of the molten metal degrades samples taken from the melt; high furnace temperatures make manipulation of sampling equipment dangerous or impossible; and dissolved gases present in the melt, such as the oxygen dissolved in the molten steel of basic oxygen furnaces, often produce porous samples with voids or gas bubbles present in the solidified metal, destroying the usefulness of the sample for many testing purposes. Uniform density samples of reproduceable quality have proved almost impossible to achieve. Wild unkilled steel having a high oxygen content has proved very difficult to sample effectively, and the unique diffusion containers of the present invention, preferably formed of thin-walled paper tubing incorporating a water-impermeable coating, provide unexpectedly effective diffusion containers for the distribution of such killing agents as finely powdered metallic magnesium throughout the molten sample.

Traditional sampling of molten metal is performed with a spoon-type ladle, dipped through floating slag, immersed deep into the melt, and withdrawn to be poured into a chill mold, forming a sample of the melt. The rising ladle stirs and agitates the melt vigorously, and accurate selection of the melt depth of the metal sample withdrawn is impossible; also, slag contamination is common, and sampling of unkilled steel carrying dissolved excess oxygen cannot be performed with such ladles.

More recently, metal pin samplers have been introduced, utilizing chill block enclosures with small entrance portals opening into small internal pin sample molding cavities in chill blocks, in which the pin molding cavity and the entrance portal are arrayed longitudinally along the downwardly extending axis of the supporting lance. These downward facing pin samplers likewise provide no control over melt depth being sampled, and they are incapable of producing samples larger than small inch diameter pins. They also risk contamination of the melt with material eroded from the entrance portal walls by the inrushing melt.

Finally, enclosed ladle samplers trapping a mass of molten metal for later solidification outside the furnace have also been tested, but these produce unrepresentative samples because volatile constituents are often vaporized and lost during the slow solidification of the trapped molten sample.

For these reasons, a sampling device capable of producing large samples solidified by quick chilling at a preselected immersion level in the melt, to deliver a solid sample for immediate testing, has become urgently needed to guide the process control of such metallurgical processes as basic oxygen furnace operations, where treatment of many tons of metal is completed with great speed, rendering conventional slow sampling, solidifying and testing procedures useless.

In determining the configuration and shape of the component parts of the sampler, a delicate timing balance is required between the chilling action of the sampler device, control of the swirling inflow of molten metal in the sampling chamber, the descent time required to lower the sampler to the immersed sampling depth desired, the corresponding time period required to vaporize the slag cover as the sampling device is plunged through the slag layer into and through upper levels of the molten metal, the shape, weight and configuration of killing material" placed in the sampler cavity to be oxidized and vaporized by the oxygen in the basic oxygen furnace melt, the intake portal shape and size required to minimize erosion contamination of the sample, and the useful working period within which the sampling device may be used safely without deterioration, cracking or damage by the intense heat of the melt. These time factors have heretofore prevented metallurgists from securing uniform, non-porous metal samples having adjacent large and small sections of radically differing diameter, useful for different metallurgical tests. Simultaneously withdrawing such two-part, dual-size samples has proved to be impossible with conventional sampling techniques.

Accordingly a principal object of the present invention is to provide molten metal sampling methods and apparatus for reliable, reproduceable sampling of molten metal by withdrawal of samples from preselected, deeply immersed sampling levels well beneath the slag layer in a body of molten metal.

A further object of the invention is to provide methods and apparatus for efficient, economical and reliable sampling of molten metal by withdrawing the sample directly from the body of molten metal in a high temperature furnace, producing large diameter samples of uniform dimensions and non-porous structure suitable for spectrophotometric analysis of their constituents and impurities.

Another object of the invention is to provide molten metal sampling methods and apparatus capable of killing substantially all of the oxygen present in the unkilled melt in a basic oxygen furnace, thus achieving the withdrawal of useful metal samples from the melt under these adverse conditions, avoiding voids and porosity in the resulting metal sample.

An additional object of the invention is to provide effective diffusion containers for distributing constituent materials or killing agents throughout a body of molten metal.

A further object of the invention is to provide molten metal sampling methods and apparatus capable of producing samples of uniform, non-porous solidified metal typically representative of the melt and having separate integral segments of radically differing diameters.

Still another object of the invention is to provide molten metal sampling methods and apparatus capable of withdrawing reliable, reproduceable solidified metal samples from basic oxygen furnaces without requiring tilting of the furnace and without interruption of the progress of the metallurgical process being performed therein, other than brief sampling interruptions of the oxygen blow supplied to the melt.

Other and more specific objects will be apparent from the features, elements, combinations and operating procedures disclosed in the following detailed description and shown in the drawings.

THE DRAWINGS FIGS. 1, 2 and 3 are successive sectional side elevation views showing successive stages in the formation of an assembled mold and its cooperation with the molding equipment to produce a molten metal assembly incorporating the features of the present invention;

FIG. 4 is a fragmentary sectional elevation view of a curing furnace in which filled molds of the kind shown in FIG. 3 are heated for curing;

FIG. 5 is a side elevation view, partially broken away in cross-section showing a partially completed metal sampler bowl portion produced by the successive operations illustrated in FIGS. 1, 2, 3 and 4;

FIG. 6 is a fragmentary schematic elevation view,

' partially in section, showing a molten metal sampler of the present invention being immersed into molten metal in a furnace;

FIG. 7 is an enlarged sectional elevation view of a completed molten metal sampler incorporating the features of the present invention;

FIG. 8 is a further enlarged fragmentary sectional plan view showing a junction portion between two mold cavity sections of the assembly shown in FIG. 7;

FIG. 9 is a cross-sectional elevation view of the pin sampler portion of the sampler assembly shown in FIG. 7, taken along the slanted plane 99 shown in FIG. 7;

FIGS. 10 and 11 are perspective front and rear corner elevation views of a shaped ceramic washer providing the transition exit portal between the mold cavities of different sizes in the assembled sampler of FIGS. 7 and 8;

FIG. 12 is an exploded perspective view, partially broken away, showing the metallic slag cover surmounting the assembled metal sampler in FIG. 7;

FIG. 13 is a perspective view of a stamped and formed chill disk stem bracket portion of the assembled sampler shown in FIG. 7;

FIG. 14is a sectional elevation view of a molten metal sampler of the present invention showing a solidified molten metal sample contained therein after withdrawal from the melt;

FIG. 15 is a sectional elevation view showing the smaller pin sample section of the solidified metal sample in the stem portion of the sampler of FIG. 14, taken along the slanted plane 15--15 of FIG. 14;

FIG. 16 is a sectional elevation view of a modified embodiment of the present invention incorporating laminated paper insulating layers surrounding the molding chill segments;

FIG. 17 is a sectional side elevation view of a further modified embodiment of the present invention designed for vertical immersion in the molten metal from a position above the melt;

FIG. 18 is a corresponding sectional side elevation view of a further modified embodiment of the invention having similar vertical immersion capabilities;

FIG. 19 is a corresponding cross-sectional side elevational view of a still further modified embodiment of the invention, with a killing agent diffusion container its structural features and stabilizing manner of operation.

SUMMARY OF THE INVENTION Molten metal samplers of the present invention differ from conventional metal samplers in having their entrance portal facing upwardly at the upper end of an enlarged central bowl portion somewhat resembling the bowl of a smokers pipe, and supported on a stem portion which may be compared structurally to the stem of the smokers pipe. The included angle between the central axes of the bowl portion and of the stem portion can be any acute angle between 0 and 90; in FIGS. 115 an angle of is shown, making the samplers useful for insertion through the side door of a furnace as indicated in FIG. 6. FIGS. 17 and 18 show modified embodiments of the invention where the bowl and stem axes are parallel, forming a 0 included angle between themselves, and samplers of this kind are useful for insertion through the roof or open top of a furnace, such as a basic oxygen furnace, a vacuum induction furnace or a Bessemer converter.

Both the bowl portion and the stem portion of the samplers of this invention are provided with central steel chill block shells, surrounded by thick layers of insulating material. This insulating material may be porous foamed ceramic material of the kind described in my copending U. S. patent application Ser. No.

710,316, filed Mar. 4, 1968, issued Feb. 9, 1971, as

US. Pat. No. 3,561,494, or it may be formed of laminated plural layers of porous paper insulation. Where a slag is not present, as in a cast iron melt in a basic oxygen furnace, the insulating layer be formed of aluminum silicate fiber, known as Kaowool, cut from sheet stock and laminated to form a thick layer of heat insulating protection for the sampler structure.

SAMPLER BOWL PORTION The successive diagrammatic views of FIGS. 1-5 illustrate successive method steps in the construction of a sampler of the kind illustrated in use in FIG. 6 and shown in the enlarged sectional views of FIGS. 7, 8 and 9. As shown in FIGS. 6 and 7, the sampler is formed for wedging assembly upon a lance tube 21, for plunging insertion into the melt 22 in the manner shown in FIG. 6. The sampler 20 is provided with a sampler bowl portion 23 integrally joined to a sampler stem portion 24.

The bowl portion 23 is formed with an upwardly opening sampling portal 26, as shown in the partially fabricated view of FIG. 5, and in FIG. 14, which is covered in use by a vaporizable metallic slag cover 27 shown in more detail in FIG. 12 and serving to close the sampling cavity 28 inside the bowl portion 23 during the plunging descent of the sampler 20 through the layer of slag 29 floating on top of the melt 22, and into the melt 22 below the slag, as shown in FIG. 6. During this plunging descent, the heat of the slag and the melt rapidly bring the slag cover temperature up to levels high enough first to melt it and then to vaporize it, completely exposing sampling portal 26 to the melt after the sampler 20 has been immersed at the preselected sampling depth in the melt, far beneath the slag layer 29.

The sampling portal 26 forms the entrance to a large sampling cavity 28 completely surrounded by a heavy steel chill tube 32 having a mass sufficient to chill the molten metal which sweeps into contact with chill tube 32 as the melt rushes into the sampling cavity 31 immediately after vaproization of the slag cover 27, urged in by the pressure head of the weight of molten metal above the sampler 20. Bonded to the outer surface of chill tube 32 is a surrounding heat-insulating sleeve 33 which serves to isolate the chill tube 32 from the external heat of the surrounding mass of the melt 22 while the sampler 20 is immersed therein.

A chill disk 34 closes the lower end of chill tube 32, and is itself surrounded on the outside of bowl 23 by a thick heat-insulating end layer 36. The insulating end layer 36 forms a unitary continuous shell with the insulating sleeve 33, as is clearly shown in the cross-sectional view of FIG. 14 where the sampler 20 is shown filled with a solidified metal sample.

SAMPLER STEM PORTION The steel chill tube 32 and the chill disk 34 together form a sturdy supporting frame for the bowl portion 23, and the chill disk 34 is provided with an upturned and outwardly projecting extension forming a stem bracket 37, best seen in FIGS. 2, 5 and 7 and in the detailed perspective view of FIG. 13. Chill disk 34 is preferably also formed with upturned gripping flanges 38 forming cantilever leaf springs extending upwardly, in generally parallel fashion for sliding engagement and slight resilient outward deformation by the outer surface of the chill tube 32, securely anchoring the chill disk 34 to the lower end of the chill tube 32, with the stem bracket 37 extending outwardly to form a single unitary steel core for the bowl portion 23 of the sampler 20. The engagement of gripping flanges 38 with the outer surface of chill tube 32 may be seen in FIGS. 5, 7 and 16.

As shown in FIG. 7, and in the cross-sectional view of FIG. 9, the stem bracket 37 is dimensioned for sliding telescoping engagement within a central steel stem tube 39 surrounded by an overlying protective heatinsulating layer 41 to form a stem portion 24 of the sample 20 of this invention. As seen in FIG. 9, the stern bracket 37 has its edges folded upward in a U-shaped configuration, and the upper and lower comer edges of stem bracket 37 thus engage the interior surface of the stem tube 39 for sliding telescoping insertion and frictional engagement therein. This engagement between the stem tube 39 and the stem bracket 37 firmly anchors bowl portion 23 to stem portion 24 in the sampler 20 configuration shown in FIG. 7. The stem tube 39 fabricated of heavy gauge steel tubing forms a sturdy structural core for the elongated tubular stem portion 24 of the metal sampler 20.

A longitudinally elongated tubular steel lance 21 is engaged telscopingly within the major portion of the internal length of the stem portion 24. As shown in FIGS. 6 and 7, the lance 21 fits loosely within the stem tube 39, as indicated in the lower portion of FIG. 7, having a few thousandths of an inch of clearance between their telescoping diameters over the major portion of the length of lance 21. At the outermost end of lance 21, remote from sampler bowl 23, however, the lance 21 is provided with an outwardly flaring taper indicated in the upper portion of FIG. 7 as taper 21A for frictional wedging engagement with the outermost end of stem tube 39. By this means the lance 21 may be telescoped within stem 24 and at its innermost position it may be jammed further into stem portion 24 for frictional engagement within stem tube 39, which is thus slightly deformed outwardly over the flared taper 21A in the manner indicated in the upper portion of FIG. 7. By this means the lance 21 and stem portion 24 of the sampler 20 become firmly anchored together during use.

As indicated in FIGS. 6 and 7, the lance 21 is provided with an enlarged coupling portion 42 having a threaded rear portal 43 accommodating the threaded end of a length of pipe 44 which may extend for ID to l5 feet in length, and whose opposite end is thus available for manipulation by the operator, who may thus be at least 15 feet from the open port 46 of the furnace in which a sampling operation is being performed.

Engagement of pipe 44 with coupling 42 and engagement of sampler stem portion 24 over the tapered portion 21A of lance 21 provides a unitary assembly, permitting easy sampling manipulation by the operator.

Coupling portion 42 is also provided with an upstanding sight 47 similar to the upstanding sight on the muzzle end of a rifle, to be observed by the operator holding the remote end of pipe 44, silhouetted against the interior glare of the furnace portal 46. The operator customarily aligns the plane determined by bowl axis 48 and stem axis 49 of a sampler 20, which may be called the sampler plane", in substantial coincidence with the plane formed by the longitudinal axis 51 of the lance 21 and the upstanding axis 47A of the sight projection 47. By this means, the operator is enabled to make sure that the bowl 23 is'positioned with its portal 26 facing upwardly at all times, despite the violent buoyant resistance to its plunging immersion during the test sampling operation as the operator plunges the sampler 20 into the melt 22.

In contrast with the approximately angle between the bowl axis 48 and the stem axis 49 shown in FIGS. 1-16, the modified samplers shown in FIGS. 17 and 18 are provided with a bowl axis 48 and with a stem axis 49A which are substantially parallel, producing an included angle of approximately therebetween. These modified samplers in FIGS. 17 and 18 are well adapted for downward vertical immersion through the top portals or openings of basic oxygen furnaces, for example. In these vertical samplers of FIGS. 17 and 18 it will be noted that the stem bracket 37A is formed with a bending slit 52 permitting it to be bent upwardly to extend in a direction substantially parallel to the bowl axis 48, thus accommodating the stem tube 39 of a stem portion 24A, sandwiching a ceramic elbow sleeve 53 between the stems end and the sidewall of the bowl portion 23. In all of the embodiments of the invention it will be noted that minor gaps or interior comers between adjacent insulating layer portions of these assemblies may. be grouted by the application of high temperature, vitreous refractory cement during the fabrication of the sampler assemblies 20 of bowl portions 23 and

stem tubes

24 or 24A.

THERMOCOUPLE I In the further modified embodiment shown in FIG. 18, a different form of elbow sleeve 54 incorporating a thermocouple 56 extending downwardly from its concave outer portion is similarly grouted in position between the stem portion 24A an the bowl portion 23, with the thermocouple 56 thus forming a downward extension of the stem portion 24A protruding downwardly along the stem axis 49A for exposure to the melt at a point near the lowest portion of the sampler 20 during its plunging immersion into the melt.

The electrical leads 57 for the thermocouple 56 are positioned within the central aperture in the elbow sleeve 54, extending therein past the stem bracket 37A in the spaces between the generally U-shaped bracket and the surrounding structures, such as the chordal segment spaces appearing in FIG. 9 between bracket 37 and stem tube 39. The thermocouple leads 57 thus extend past bracket 37A into the interior of the stem tube 39, and thence through central bore 58 in lance 21. They extend inside lance 21 along the entire length of stem tube 39, through the pipe coupling 42, and along the interior of pipe 44 to the operators sampling position. The thermocouple leads 57 are thus protected by a casing of steel in pipe 44, coupling 42 and lance 21 throughout their length along the entire sampler assembly, and in the assembly portion inserted into the furnace, he stem portion 24A of sampler 20, the leads 57 are further protected by the insulating layer 41 surrounding the stem portion 24.

As indicated in FIG. 17, chill tube 32 and its surrounding insulating sleeve 33 may both be unbroken at the point where the stem 24A joins the bowl 23 except for the fact that stem bracket 37A preferably extends through the insulating sleeve 33 at this point to form a solid unitary anchoring structure by virtue of its frictional wedging engagement inside the stem tube 39A of the stem portion 24A. In this configuration, the sampler is well adapted to receive, solidify and withdraw uniform, non-porous, cylindrical samples of metal having an outside diameter corresponding to the inside diameter of the chill tube 32, and this single diameter sample unit may be formed either in the large included angle version illustrated in FIGS. 1-16, or in the verti- NON-POROUS SAMPLES In all forms of the invention, two features avoid porosity, bubbles or pipes in the solidified, molded sample withdrawn from the melt. Firstly, the upward facing portal 26 allows air enclosed within the sampling chamber 31 to be displaced upwardly by the inrushing molten metal entering the cavity 28 as soon as the slag cover 27 vaporizes. The drastic difference of specific gravity of the molten metal and the displaced air avoids any possibility of entrapped bubbles of air in the solidified sample. Secondly, porosity can result from the precipitating or boiling off of entrained dissolved excess oxygen in the melt, supplied by the oxygen blow operation during the treatment of the metal in a basic oxygen furnace or in a Bessemer Converter, for example, to oxidize excess carbon and reduce the carbon content from undesirable high cast iron" carbon content levels present in ore or pig iron, to the much lower carbon contents required for high quality steel.

To eliminate porosity caused by this high oxygen content in the portion of the melt rushing into thechill tube 32, an antioxidant or killing agent in the form of a body of metal of small cross-section selected from the group consisting of aluminum, magnesium, titanium and silicon is positioned in the sampling cavity 28 inside chill tube 32. This metallic killing agent may take any desired shape having 5 minimum cross-section presented to the inflowing melt, and is preferably distributed vertically over the entire vertical height of the sample cavity 28. For example, the killing agent may be configured in the shape of a conical, helical, coil spring 61 whose lowermost turns are dimensioned for resilient, deformed, sliding, wedging engagement inside the lower end of cavity 28 definedby the internal diameter of chill tube 32, and whose upper turns are progressively smaller to being them closer to the cen-.

tral axis 48 of bowl 23. The inrushing flood of moltention of the metal, with the dissolved oxygen boiled off. The killing agent and the oxygen then combine to form oxides of the magnesium, titanium, aluminum or silicon killing agent, all of which have far lower specific gravities than the molten metal and which therefore escape and rise quickly from the sampling cavity 28 toward the surface of the melt to join the slag layer 29 floating there.

In certain high quality alloy steels, aluminum is an undesired impurity, and in these cases the killing agent spring 61 and the slag cover 27 are preferably both formed of magnesium, so that any traces thereof remaining in the sample or in the main body of molten metal will be traces of a desirable alloying'element, magnesium, rather than an undesired trace impurity, aluminum. Thus the choice of metallic killing agent for the metal insert 61 depends upon the formulation of the molten metal to be tested, but for most'testing n operations aluminum is the preferred killing agent, and aluminum is also the preferred material for the slag cover 27 in most cases.

CONTIGUOUS PIN SAMPLE SEGMENTS In the embodiments of the invention illustrated in FIGS. 1-16, there is provided a highly desirable advantage of the present invention, its capability for the formation of a secondary portion of the solidified metal sample withdrawn from the metal in the shape of a small diameter pin sample. From the large diameter sample segment contained within the chill tube 32, cross-sections may be cut and polished for spectrographic analysis, insertion in a mass spectrophotometer, or similar spectral analysis techniques; in addition, small diameter pin" samples are extremely useful for gas analysis to determine the oxygen content of killed steel or the presence or amount of other gaseous impurities present in the melt. In my copending patent applications, Ser. Nos. 560,723 and 560,724, both filed June 27, 1966, and issued respectively July 29, 1969 as US. Pat. No. 3,457,790 and July 2, 1969 U.S. Pat. No. 3,452,602 I have disclosed sampling devices suitable for the formation of pin samples alone, and the samplers described herein are believed to be the first samplers capable of producing solidified samples of molten metal withdrawn simultaneously from the melt and having two drastically different diameters, to be used for parallel testing purposes by different test techniques to determine constituents and characteristics of the melt. In these dual-sample embodiments of the invention, an exit portal 62 is formed in a portal insert 62 positioned in the lower sidewall of the sampling cavity 28, in a suitable opening formed in chill tube 32, leading directly into the stern portion 24 of the sampler assembly 20.

Exit portal 62 opens directly into a pin sampler mold, which may be a quartz tube 64 positioned between the upturned sides of the U-section stem bracket 37, as indicated in FIGS. 1, 3, 5, 8 and 9, and anchored therein by suitably placed droplets of vitreous cement 66. A slotted cylindrical riser tube 67 preferably having a longitudinal slot 68 extending from end to end along one side thereof is telescopingly mounted surrounding the outer end of the pin sampler mold 64 within the U-section stem bracket 37, as shown in FIGS. 7 and 9, and the riser tube is provided at its outer end remote from the bowl 23 with a suitable end blocking plug 69.

The foregoing features cooperate structurally to form a continuous passageway leading from the sampling cavity 28 through the exit portal 62 into the interior of the pin sampler mold 64, and thence into the inside of the riser tube 67 and through the slot 68 therein into the interior of the stem tube 39 leading to the central bore 58 formed in the lance 21. By this means, in addition to the pen sampling portal 26 through which air entrapped beneath slag cover 27 is displaced for escape by the inrushing flood of molten metal into the sampler cavity 28, supplemental air escape route 62 64 68 58 permits the inrushing melt, already killed by killing agent 61, to surge instantly through exit portal 62 into pin sampler mold 64 and partway up riser tube 67 as the escaping air exits therefrom through slot 68. The chilling effect of the relatively cold air and the relatively cold structures of sampler mold 64 and riser tube 67 quickly chill the inrushing surge of molten metal to form a solidified; cylindrical pin sample within the mold portion 64. Excess metal passing through the mold portion 64 into the riser tube 67 may ooze outward through slot 68 where it generally solidifies, as indicated in FIG. 15.

With all of the samplers of the present invention, the sampler assembly 20 supported on its lance 21 and pipe 44 is raised and withdrawn through the furnace portal 46 or through the open top of a basic oxygen furnace in the case of the two vertical sampler configurations shown in FIGS. 17 and 18 after a comparatively brief immersion in a molten metal bath 22. A sampling period of from 6 to 12 seconds is normally adequate to secure solidified samples from preselected sampling levels deep within the melt with the samplers of this invention, without danger that the sampler itself will be damaged or destroyed by the heat of the melt. Indeed if

heat insulating layers

33, 36 or 41 should crack under the intense melt heat, the pressure head of the molten metal in the melt generally holds any cracked portions tightly against the underlying metal structure 32 34 37 39 during the remainder of the sampling operation, normally avoiding any degrading or remelting of the metal sample being taken.

FABRICATION TECHNIQUES The successive views of FIGS. 1 through 5 show successive stages in the fabrication of a sampler incorporating the features of the present invention, having heat insulating layers surrounding its chill tube sample mold means comprising a foamed porous heat insulating ceramic material of the kind disclosed in my copending U. S. patent application, Ser. No. 710,316, filed Mar. 4, 1968, These porous ceramic materials incorporate stable foam forming agents, such as surface active agents, to promote and stabilize the formation of fine cellular foam in the ceramic slurry during its formulation and curing, to form a solidified lightweight ceramic composition of porous character and excellent heat insulating qualities coupled with high temperature resistant refractory characteristics. The preferred compositions and formulation methods and techniques disclosed in my copending U. S. patent application, Ser. No. 710,3 16, are hereby incorporated by reference herein for all purposes.

As shown in FIG. 1, the formation of such porous heat insulating ceramic layers to form sleeve 33 and insulating end layer 36 is facilitated by first positioning the chill tube 32, having the chill disk 34 stern bracket 37 assembly secured thereto through the gripping action of flanges 38, at a molding station where this assembly is surrounded by a mold shell 71. The mold shell 71 comprises an enlarged mold sleeve 72 spaced outwardly surrounding the chill tube 32 at a radial distance corresponding to the radial thickness of the heat insulating sleeve 33 and having its lower end shown at the right hand side in FIG. 1 closed by a bottom disk 73 spaced outwardly away from the outer or lower surface of the chill disk 34 by the thickness described in my copending U. S. patent application, Ser. No. 710,316. The bottom disk 73 may be formed as a disk having an outer diameter larger than the internal diameter of mold sleeve 72 and having a drawn upturned rim 74 formed around its periphery, reducing the effective outer diameter of the disk 73 sufficiently to allow it to be forced into the open lower end of mold sleeve 72 with the upturned rim portion 74 being bent into a longitudinal position, frictionally engaging the internal wall surface of mold sleeve 72, as shown in FIG. 1. Bottom disk 73 is preferably spaced away from the outer surface of chill disk 34 by such means as a ceramic spacer sleeve 77. In the molding assembly shown in the figures, a central alignment pin 78 is shown cemented or welded to the outside central portion of chill disk 34 projecting axially in the downward direction along the bowl axis 48. The ceramic spacer sleeve 77 may be positioned around pin 78, and a central alignment aperture formed in bottom disk 73 may be telescopingly engaged over pin 78 during the assembly of mold shell 71 over the assembled metallic central portions of the sampler unit.

A ceramic slurry delivery nozzle 79 comprising radially spaced-apart inner tube 81 and outer tube 82 forms an annular slurry delivery passage 83 between these two tubes, through which the foamed ceramic slurry may be delivered under sufficient pressure to cause it to be extruded from the open exit end 80 of the annular delivery passage 83 shown at the right end of this nozzle assembly 79 in FIGS. 1 and 2, after the assembled mold shell 71 and chill tube 32 have been telescopingly inserted in endwise overlapping relationship with nozzle 79. Mold sleeve 72 is dimensioned for a close sliding fit outside the outer diameter of outer tube 82 of the nozzle 79. The inner tube 81 of the nozzle 79 is dimensioned for a close sliding fit just outside chill tube 32.

As indicated in FIG. 2, the foamed ceramic slurry composition then advances from left to right along the passage 83 between the

tubes

81 and 82 of nozzle 79 and issues therefrom at exit 80 to fill the space between chill tube 32 and sleeve 72, and also the end space between chill disk 34 and bottom disk 73 surrounding the ceramic spacer sleeve 77 as well as the portal insert 63 and the exposed portions of pin sampler mold 64 and stem bracket 73 positioned inside mold sleeve 72.

After the flowable foamed ceramic slurry has completely filled the spaces between the central metal chill portions of the sampler and the outer mold sleeve 72 and bottom disk 73, the assembly of the metal sampler units and the outer mold sleeve 72 of disk 73 is removed from telescoping engagement with the slurry delivery nozzle 79, and an opposing drawn end cap 84 having an upturned rim portion 86 is moved by telescoping sliding insertion into the open end of mold sleeve 72 opposite to the bottom disk 73,forming an upper cap closing the open sampling portal 26 in the end of chill tube 32. In the preferred techniques of the invention, as illustrated in FIG. 3, end cap 84 is provided with an inwardly protruding central boss portion 87'which is itself dimensioned for telescoping sliding engagement within the internal diameter of chill tube 32.'Being centrally and coaxially positioned as an integral part of end cap'84, boss portion 87 thus acts as a centering plug, securing the coaxial relationship between chill tube 32 and mold sleeve 72 to assure the even, uniform distribution of the flowable ceramic slurry material therebetween in substantial uniform radial thickness around it entire periphery.

As shown in FIG. 3, the filled mold now comprises sleeve 72 with bottom disk 73 and end cap 84 firmly secured therein, and having the metal chill tube 32 and associated metal parts securely centered in the desired central position, surrounded by foamed ceramic slurry. The stem bracket 37, with the pin sampler mold 64 secured therein by droplets 66 if desired, protrudes through a suitable aperture 88 formed in the sidewall of mold sleeve 72. If the pin sampling mold 64 is omitted, the slurry surrounds stem bracket 37 within tube 72, producing the incompassing layer 33 shown in FIG. 17.

These assembled and slurry-filled mold units 72 are then ready for curing, and they are each preferably positioned utilizing the alignment pin 78, by engaging it in a suitable aperture in a supporting trayv 89, on which a plurality of the filled mold units 72 may be placed for oven curing in the baking oven 91, in the manner shown in FIG. 4.

After curing, the outer mold sleeve 72 and bottom disk 73 may be peeled and stripped away from the cured

ceramic layers

33 and 36 and the pin 78 may be sheared off, flush with the outer surface of insulating end layer 36 solidified around the ceramic .spacer sleeve 77. The removal of end cap 84 completes the stripping of the molding parts from the completed sampler bowl portion, as indicated in FIG. 5, and the riser tube 67 having its longitudinal side slot 68 and outer end cap 69 may be telescopingly engaged over the outermost end of the pin sampler mold tube 64. The'stem portion 24 formed of the stem tube 39 surrounded by the overlying heat insulating porous ceramic layer 41 formed in the manner describedin my copending U. S.

patent Application, Ser. No. 710,316, filed Mar. 4, 1968, of the same ceramic slurry compositions cured by oven baking as there described, is then telescopingly mounted over the vent tube 67 in sliding frictional en gagement with the corners of the stem bracket 37, and advanced to the closely juxtaposed engaged position shown in FIGS. 7 and 9. Any remaining crevices.

between the stem portion 24 and the bowl portion 23 may then be grouted with suitable refractory cement 92, as shown in FIGS. 7 and 8.

The alternative paper insulated sampler assembly illustrated in FIG. 16incorporates most-of the principal features of the ceramic insulated assemblies previously described, but the heat insulating sleeve 33A and the insulating end layer 36A therein are formed of laminated layers of paper or pasteboard material incorporating substantial amounts of air-filled porosity within their assembled structure, and thereby furnishing an ablative heat insulating layer which is charred and destroyed during insertion in the melt, but which survives long enough to insulate and protect chill tube 32 and the associated mold cavity parts of the sampler from the furnace heat during the short 10 or 12 second period required for withdrawal of a suitable metal sample. Explosively expanding air and gas produced by the heat destruction of these layers may produce violent boiling and spattering of the melt, requiring careful handling precautions to assure operators safety. In the,

assembly 20A shown in FIG. 16, the insulating layer 41A surrounding the stem tube 39 of the stem portion 24 is likewise formed of laminated layers of paper or pasteboard with the open spaces required for assembling these pasteboard insulating portions being grouted as before with suitable refractory cement 92, as indicated in FIG. 16.

The portal insert 63 shown in FIGS. and 11 generally comprises a small curved block of ceramic material precast in the desired shape for assembled insertion in a suitable aperture in chill tube 32. The insert 63 is formed with a concave cylindrical surface 93 shaped for juxtaposed engagement around the outer surface of chill tube '32 as indicated in FIGS. 2 and 8, and a portal flange 94 extends inwardly from the concave surface 93 having a smoothly rounded entrance connecting with and blending smoothly into the central exit portal 62, as shown in FIG. 8. The opposite outer surface of the portal insert 63, as shown in FIG. 11, may have a saddle-shaped curved rim 96 corresponding generally to the curvature of surface 93 and chill tube 32. A shallow recess 97 formed within the rim 96 provides a suitable space for the juxtaposition of the portal end of pin sampler mold tube 64 which is positioned in close proximity thereto when tube 64 is assembled in stem bracket 37 by droplets 66 of refractory cement.

Accordingly, all of the structural components of the samplers of the present invention are highly resistant to the temperatures encountered in molten metal sampling procedures, and the heat insulating ceramic layers surrounding the outside of sampler bowl 23 and stem 24 serve to provide heat sink capabilities enhancing the chilling effect of the chill tube 32 by preserving its relatively low temperature in contrast with the high temperatures of the inrushing molten metal during the brief sampling period, thus promoting the solidification of the molten metal to form the desired metal sample within the sampler 20. The features and their configurations here described cooperate to provide coinciding short timing periods for heating of slag cover 27 by the melt and its vaporization as the sampler is submerged to the preselected sampling level, inflow and killing of the melt, chilling formation of a pin sample in mold 64 and a large contiguous sample for spectrographic analysis in chill tube 32, both nearly or completely solidified by the chilling action of the samplers metal parts as the sampler is withdrawn from the melt, thus achieving all of the objects set forth above with speed and convenience.

DIFFUSION CONTAINERS By taking advantage of the explosive vaporization and turbulent boiling characteristics produced upon immersion of the paper structures such as the sampler FIG. 16, unexpectedly effective distribution and diffusion of constituent materials, such as finely powdered magnesium killing agents, can be achieved. This technique can be used on a large scale for the introduction and highly uniform diffusion of constituent materials throughout the melt, and by taking advantage of this phenomenon, a very high oxygen content of wild, unkilled steel melt may be sampled effectively by killing the molten sample while it is being collected and frozen in the sampler.

A diffusion container 98 utilized to distribute the killing agent, such as finely powdered magnesium,

throughout the molten sample is shown in FIGS. 19 and 20. Container 98 comprises a tubular enclosure formed of a thin-walled paper tube similar to a soda straw, and enclosing a finely powdered material, such as pow dered magnesium. In the samplers of this invention, a measured quantity 99 of magnesium powder, finely divided and graded for passage through a 325-mesh screen, is loaded inside container 98. An amount 99 between 1.0 and 1.5 grams of magnesium powder provides an ample quantity of killing agent for use with the samplers of the present invention, and the amount of killing agent may be varied as required for different 0xygen contents of the molten steel.

As indicated in FIGS. 7, 16 and 19, the anti-oxidant is vertically distributed, whether it is a ribbon, a wire, a

- isolated from sparks, heat, or open flames. Ac-

cordingly, the container 98 is preferably formed of moisture-impervious materials such as waxed paper, and its ends are flattened, reversely folded to form end folds 100 and suitably sealed by such means as adhesives, heat sealing, paraffin-dipping or the like. In FIG. 20, an end coating 101 produced by paraffin dipping of reversely folded flattened and sealed ends 100 of a container 98 is shown at both the lower and upper ends of the container. If desired the entire container may be paraffin dipped after being filled with powdered magnesium, to assure moisture-proofing of the packaged killing agent in container 98. If desired, container 98 may be formed of a thin walled plastic tube, thin sheet metal or laminates of these materials with or without paper layers.

The sampler 106 of FIG. 19, enclosing within its chill tube the killing agent carried in container 98, has proved safely and conveniently storable for considerably periods of time under normal storage conditions, and under emergency conditions has safely withstood slag spills in the vicinity of basic oxygen furnaces in steel mills without harming the sampler or the killing agent enclosed therein, both of which were used thereafter with normal effectiveness for killing a sample of wild unkilled steel with uniform and reproducible effectiveness.

To assure isolation of finely powdered magnesium, it is normally shipped in closed metal drums or cans. The chill tube 32, chill disk 34 and slag cover 27 forms just such a closed metal container, as shown in FIG. 19, since the downwardly extending ridge encircling cover 27 is slightly oversize for an interferring force fit within sampling portal 26 of chill tube 32, as indicated in FIGS. 7 and 16.

Slag cover 27 serves to keep the sampling chamber clean and protects the deoxidant 61 or 99 during storage, and also keeps slag out of the sampling chamber during immersion until sampling depth has been reached. Certain slags freeze on an immersed piece of steel, undesirably insulating cap 27 against melting at the desired depth. Accordingly, cover 27 may be formed of laminated assemblies of paper, plastic, various metals, or combinations thereof. For example, an exposed upper layer of sheet aluminum or paper melts and vaporizes with enough turbulence to avoid such undesired slag deposits on cover 27.

If desired, the sampler 106 may be provided with two similar sampler bowls 33, as indicated in FIG. 23, providing two samples secured simultaneously from the melt with the single plunging immersion of lance 102. As indicated in FIG. 19, the bowl 33 of the sampler 106 is provided with a chill disk stem bracket 107 extending continuously from the chill disk 34 into the suitable apertured lower end of the vertical sampler stem portion 24A whose lower end is suitably grouted with cement to enclose the stem bracket 107 as is shown in FIG. 19. If desired a thermocouple similar to that of FIG. 18 may be incorporated in the vertical sampler bowl assembly 106 of FIG. 19 or the dual bowl assembly illustrated in FIGS. 21 and 23.

CONSTITUENT DIFFUSION TECHNIQUES The diffusion container 98 of FIG. 20 may be adapted for the diffusion of a constituent throughout a body of molten metal, whether or not sampling is required. For example, a plurality of containers 98, containing the same or different finely powdered constituents to be distributed throughout the melt, may be introduced beneath the slag layer into the body of molten metal together or separately in one or more immersion operations. Particularly when it is formed of thin paper sheet or waxed paper, the highly explosive vaporization of the container 98 when exposed to such temperatures as the basic oxygen furnace temperatures of molten steel produces unusually effective distribution of the finely powdered material enclosed within container 98 throughout the melt. Thus, these explosively vaporized diffusion containers provide a unique and highly effective metallurgical tool for the distribution of powdered alloying substances, killing agents, and the like, in thorough and uniform diffusion throughout the body of molten metal.

VERTICAL SAMPLING PROCEDURES Natural buoyancy of the samplers of FIGS. l7, l8 and 19, when they are plunged into a body of molten metal, requires a stabalizing procedure to avoid their lateral deflection from their downward path of travel along their vertical immersion path into the melt. For this purpose, the stabilized or counterweighted sampling lance illustrated in FIGS. 21-23 has proved unexpectedly effective. This stabilized vertical immersion lance preferably incorporates an elongated lance 102, corresponding to the lance 21 of FIGS. 6 and 7, extending along a vertical axis and having a terminal hoisting ring 103 formed at its upper end.

A relatively heavy stabilizing plate 104 comprising a wide, heavy, disk-shaped flange extends radially in all directions from lance 102. The stabilizing plate 104 may be 1 inch thick and 2 feet in diameter, for example, and may be positioned about 1 foot below the hoisting ring 103. Preferably, sampler stem tube 24A telescopes within an annular splash guard flange depending beneath plate 104, diverting explosive, turbulent slag eruptions from entering the upper end of tube 24A.

The thickness and diameter of stabilizing plate 104 are selected to assure that the major portion of the overall weight of the lance 102 and the sampler 106 secured thereon, will be concentrated in the plate 104 whose center of gravity is substantially concentric with the axis of lance 102, and positioned by a substantial righting arm distance beneath terminal hoisting ring 103. As a result, any lateral deflection produced by the buoyance of the sampler 106 tending to pivot lance 102 angularly about its terminal hoisting ring 103 is counteracted by the heavy weight of stabilizing plate 104. Since the weight W of lance 102 may be considered to act through its center of gravity C.G. near the center of stabilizing plate 104, buoyant lateral deflection of the lance assembly moves C.G. away from the normal vertical hoisting axis 105 passing through terminal ring 103 by a righting arm distance R.A. which increases with each additional increment of lateral deflection. Since the stabilizing or righting moment W x R.A. thus increases with buoyant lateral deflection, it produces increasing stabilizing action similar to that achieved by the keel of a sailboat having a deep fin keel. The stabilized lance assembly 102 thus provides highly effective vertical plunging immersion for sampling the melt of a basic oxygen furnace without any need for tilting the furnace vessel.

Since the foregoing description and drawings are merely illustrative, the scope of the invention has been broadly stated herein, and it should be liberally interpreted to secure the benefit of all equivalents to which the invention is fairly entitled.

What is claimed is:

l. A molten metal sampler comprising A. an enlarged heat-resistant sampler bowl portion surrounding a heat-conductive, vertically elongated chill tube encompassing a vertically elongated central sampling cavity having substantially uniform cross-sectional area throughout its depth, surmounted at its upper end by an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube;

B. and 'a heat resistant sampler stem portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal;

C. the wall-thickness and consequent heat-absorbing mass of said chill tube being selected to provide cooling of the inrushing melt entering said sampling cavity at a cooling rate maintaining the sampled melt molten while it fills the cavity, and solidifying it only after the cavity is filled.

2. The sampler defined in claim 1 wherein the chill tube is formed as a thick-walled cylindrical tube defining a substantially cylindrical sampling chamber and incorporates a protruding stem bracket extending outwardly for anchored engagement with the sampler stern portion.

3. The sampler defined in claim 1 wherein the upper end of the chill tube forms the upwardly facing unobstructed entrance portal of the sampling cavity.

4. The sampler defined in claim 1 further including a thin metal slag cover secured blocking the entrance portal and having a thickness selected to provide a heat conduction rate bringing the slag cover to its melting point in a time period slightly greater than the time nor- 5 mally required for the plunging immersion of the sampler to a preselected depth within the mass of molten metal.

5. The sampler defined in claim 4, further including an elongated body of deoxidizing material positioned in the chill tube and arrayed along the chill tube in the direction of its longitudinal axis.

6. The sampler defined in claim 5, wherein the deoxidizing material is formed as an elongated coil.

7. The sampler defined in claim 1 wherein the bowl portion and the stem portion have respective longitudinal axes angularly converging at an acute angle.

8. The sampler defined in claim 1 wherein the bowl portion and the stem portion have respective longitudinal axes which are substantially parallel, for substantially vertical downward plunging immersion of the sampler bowl into the mass of molten metal.

9. The sampler defined in claim 1, further including a pin sample mold forming a pin sample molding cavity adjacent to and smaller than the central sampling cavity.

10. The combination defined in claim 1, further including a thermocouple mounted protruding downwardly from the sampler at a point near the junction of the sample bowl portion and the sampler stem portion, wherein the thermocouple is provided with electrically conductive lead wires extending through the heat insulating layer into an interior bore formed in the stem portion.

1 l. A molten metal sampler comprising A. an enlarged sampler bowl portion having a chill tube encompassing a central sampling cavity with an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube;

and a heat resistant sampler stem portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal;

C. wherein the chill tube incorporates a protruding stem bracket extending outwardly for anchored engagement with the sampler stem portion; and

D. wherein the stern bracket is formed as a protruding section of a chill disk anchored to the lower end of the chill tube to enclose the lower end of the central sampling cavity.

12. The sampler defined in claim 1 1 wherein the chill disk is detachable secured to the chill tube, whereby the stem portion may be easily separated from the bowl portion by an impact blow to release the chill tube and the metal sample therein from the associated sampler parts for immediate metallurgical analysis.

13. A molten metal sampler comprising A. an enlarged sampler bowl portion having a chill tube encompassing a central sampling cavity with an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube; B. a heat resistant sampler stem portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal;

C. and a pin sample mold forming a pin sample molding cavity adjacent to and smaller than the central sampling cavity, wherein the pin sample mold is a tubular mold secured to a stem bracket protruding from the chill tube, and further including means forming an exit portal passing through a sidewall portion of the chill tube and its surrounding heatinsulating layer and opening into an entrance end of the pin sample mold.

14. The sampler defined in claim 13 further including a vented riser tube telescopingly secured to the exit end of the tubular pin sample mold opposite to its entrance end, and having air escape vent means of small cross-section compared to its overall volume communicating with a hollow central bore in the sampler stern portion which is telescopingly anchored over the stem bracket to which the pin sampler mold is secured.

15. The sampler defined in claim 13 wherein the sampler stem portion and a supporting lance are telescopingly anchored tubular hollow members.

16. The sampler defined in claim 13, wherein the exit portal means is formed in a non-metallic portal insert juxtaposed between the pin sample mold and the chill tube and having a portal flange extending through an enlarged aperture in the chill tube, whereby the molten metal entering the exit portal from the sampling cavity is insulated from chilling metal parts of the sampler.

17. A molten metal sampler comprising A. an enlarged sampler bowl portion having a chill tube encompassing a central sampling cavity with an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube;

B. a heat resistant sampler stern portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal;

C. a thin metal slag cover secured blocking the entrance portal and having a thickness selected to provide a heat conduction rate bringing the slag cover to its melting point in a time period slightly greater than the time normally required for the plunging immersion of the sampler to a preselected depth within the mass of molten metal;

D. and an elongated body of deoxidizing material positioned in the chill tube and arrayed along the chill tube in the direction of its longitudinal axis, wherein the deoxidizing material is a powdered metal surrounded by an elongated tubular diffusion container positioned within the chill tube.

18. The sampler defined in claim 17, wherein the tubular diffusion container is formed of wax impregnated paper, and the deoxidizing material comprises powdered metallic magnesium.

Col Col; Col

Col C01 Col Col

Col

C01 Col Col Col FORM PO-105O HQ- Patent No.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Inventor(s) Dated August 29,1972

ROBERT J. HACKETT It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

"vaproization" should Joe-vaporization- "telscopingly" should be-telesoopingly- "port" should be-portal- "an" should be-and- "being" should be-bring- "metal" should be-molt- I "62" second instance should be-63- "pen" should be open- 0,1.36 '5" after 1968 should be' 11',l .47 "73" Should b6 37- 12,1 .3 "it" should be-its- 12,1 .14 12,1 .50 14,1.62 C01.15,1.52 Col.16,l.l3 Col .17,l.55 C01.18,1,24

"'incompassi ng" should Ice-encompassing- '"ceramio-insulated" should be-ceramic-insu'lated- "interferring" should beinterfering- "stabalizing" should be-s-tabilizing- "buoyance" should be-buoyancy- "detachable" should be-detachably- "sampler" should be-sample- Insert the attached sheet of drawing containing figures 19 through 23.

Signed and sealed this 8th day of May 1973.

(SEAL) Attest:

EDWARD'MFLETCHER'JR. Attesting Officer ROBERT GOTTSCHALK Commissioner ofPatents USCOMM-DC 60376-969 n u.s GOVERNMENT PRINTING ornc: I969 0-356-334 2 PATENT NO. 3,686,949 DATED August 29, 1972 Baker? I 17 6 0. mvmrm 8 are 5217mm r W flTYORNJTYS'.

Claims

1. A molten metal sampler comprising A. an enlarged heat-resistant sampler bowl portion surrounding a heat-conductive, vertically elongated chill tube encompassing a vertically elongated central sampling cavity having substantially uniform cross-sectional area throughout its depth, surmounted at its upper end by an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube; B. and a heat resistant sampler stem portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal; C. the wall-thickness and consequent heat-absorbing mass of said chill tube being selected to provide cooling of the inrushing melt entering said sampling cavity at a cooling rate maintaining the sampled melt molten while it fills the cavity, and solidifying it only after the cavity is filled.

2. The sampler defined in claim 1 wherein the chill tube is formed as a thick-walled cylindrical tube defining a substantially cylindrical sampling chamber and incorporates a protruding stem bracket extending outwardly for anchored engagement with the sampler stem portion.

4. The sampler defined in claim 1 further including a thin metal slag cover secured blocking the entrance portal and having a thickness selected to provide a heat conduction rate bringing the slag cover to its melting point in a time period slightly greater than the time normally required for the plunging immersion of the sampler to a preselected depth within the mass of molten metal.

11. A molten metal sampler comprising A. an enlarged sampler bowl portion having a chill tube encompassing a central sampling cavity with an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube; B. and a heat resistant sampler stem portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal; C. wherein the chill tube incorporates a protruding stem bracket extending outwardly for anchored engagement with the sampler stem portion; and D. wherein the stem bracket is formed as a protruding section of a chill disk anchored to the lower end of the chill tube to enclose the lower end of the central sampling cavity.

12. The sampler defined in claim 11 wherein the chill disk is detachably secured to the chill tube, whereby the stem portion may be easily separated from the bowl portion by an impact blow to release the chill tube and the metal sample therein from the associated sampler parts for immediate metallurgical analysis.

13. A molten metal sampler comprising A. an enlarged sampler bowl portion having a chill tube encompassing a central sampling cavity with an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube; B. a heat resistant sampler stem portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal; C. and a pin sample mold forming a pin sample molding cavity adjacent to and smaller than the central sampling cavity, wherein the pin sample mold is a tubular mold secured to a stem bracket protruding from the chill tube, and further including means forming an exit portal passing through a sidewall portion of the chill tube and its surrounding heat-insulating layer and opening into an entrance end of the pin sample mold.

14. The sampler defined in claim 13 further including a vented riser tube telescopingly secured to the exit end of the tubular pin sample mold opposite to its entrance end, and having air escape vent means of small cross-section compared to its overall volume communicating with a hollow central bore in the sampler stem portion which is telescopingly anchored over the stem bracket to which the pin sampler mold is secured.

17. A molten metal sampler comprising A. an enlarged sampler bowl portion having a chill tube encompassing a central sampling cavity with an upwardly facing unobstructed entrance portal, and having a layer of heat insulating material surrounding the lateral sidewalls and the lower end of the chill tube; B. a heat resistant sampler stem portion anchored to the bowl portion and extending therefrom toward a sampling position from which the sampler can be plungingly immersed to a preselected depth within a mass of molten metal; C. a thin metal slag cover secured blocking the entrance portal and having a thickness selected to provide a heat conduction rate bringing the slag cover to its melting point in a time period slightly greater than the time normally required for the plunging immersion of the sampler to a preselected depth within the mass of molten metal; D. and an elongated body of deoxidizing material positioned in the chill tube and arrayed along the chill tube in the direction of its longitudinal axis, wherein the deoxidizing material is a powdered metal surrounded by an elongated tubular diffusion container positioned within the chill tube.