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Dec. l0, 1935. _ A. WEI-'ING 2,023,776 PRODUCTION OF SEAILESS TUBES AND OTHER ELONGATE ARTICLES Filed May 4, 1934 Ä Kia-kf» , 1`NVEN TOR.' "0; ís" ATTORNEYS. ____-_J 2,023,776 Patented Dec. 10, 1935 UNITED STATES ' PATENT ori-‘ICE PRODUCTION OF` SEAMLESS TUBES AND OTHER ELONGATE ARTICLES Adolf Weiing, Witten/Ruhr, Germany, assignor ' to Tubus A. G., Zurich, Switzerland l . Application May 4, 1934, Serial No. 723,842 In Germany January 13, 1933 3 Claims. This invention relates to the manufacture of seamless tubing and similar elongate metallic ar (Cl. 29-156) particularly from ferrous metals, such as steels, by a process which confers the advantages of extrusion procedures but in which larger billets may be operated upon, to provide greater lengths of product, than economically practical hereto- 5 fore,- in which the exaggerated mandrel wear here tofore encountered in extruding large size billets is minimized, which is rapid, readily operated, and otherwise embodies procedural and economic ad vantages, such as the use of standard types of 1n' ticles, such as solid sections, e. g., rods For ease of reference and for purposes of i1 5 lustratlon the productionof seamless tubes may be referred to, although the invention is not limit ed thereto. 4In ordinary processes of producing seamless tubes> a multiplicity of steps are nec essary, including the forming of a billet, heating 10 the billet, piercing the heated billet, and elon gation of the pierced billet in one of the conven , tional apparatuses, such as a pilger mill. There after the blank is commonly subjected to a reduc ing operation, to bring it to desired size, and for this purpose reheating of the elongated blank is necessary prior to reduction, and, itmay be, apparatus. v ‘ -~ In accordance with this invention seamless tubes and the like articles of Vgreat length relative to their section are made by extruding a heated billet to forman oversized article in a heated 15 condition, and while the article isthus heated l reducing it to the desired size. Referring to the also between various steps of the reducing op » manufacture ofl seamless tubes as anl example, a eration. Such procedures are disadvantageous heated billet of metal is extrudedin a suitable ` because of the multiplicity of steps and the addi . extrusion press, using ya mandrel and die of tional heating operation required for reducing, 20 which adds to the cost burden, materially slows such size as to produce a tubek of greater diameter than that desired. This oversized tube exudes down production, and may be otherwise objec from the die opening of the press in a highly heat tionable. ’ ed condition, and I have, discovered, and it is The extrusion process is theoretically more at -upon this that my invention is predicated in part, 25 tractive because it affords a means of producing 2 Ul seamless 'tubes in a single step. This operation that the heat thus inherently` in the tube as ex truded is suiiicient to permit «it to be reduced to ls advantageous not only for that reason, but also the desired size by »subjecting it, without reheat- " because it is applicable, generally speaking, to ing, to a suitable reducing or sinking operation, for all grades of common and alloyed steels. By vir example, in a sink mill, or a suitable‘pilger or 30 tue of these features the extrusion production of other mill, various types of which are known in 30 seamless tubes and the like elongate articles should be cheaper than the processes ordinarily The accompanying drawing is a diagrammatic used, such as those referred to hereinabove. The 1 view, partly in section, illustrative of `one embodi greatest economy would follow from the use of ment of the method provided by the invention and large billets, for thereby'fewer operations would 35 produce longer tubes than Where small billets showing the formation of an oversized tube by extrusion and its conversion to a sized tube with ' are extruded. When it is attempted tofuse large billets, however, there is encountered the serious drawback that as the size of the billet is increased in the production of a tube of given size, the wear 40 and tear upon the mandrel is definitely and mate rially greater, as compared with the production of tubes of the same size from smaller billets. This factor may become so serious in attempting to use large billets as to’oiîset other advantages of the extrusion process. ' It is a major object of this invention to pro duce seamless tubes andother elongate articles 50 of relatively small section, e.' g., not more than about three inches in diameter or greatest width, the art. - f .out intermediate heating. « ' , ., In order to utilize the residual heat of extru sion to avoid reheating for the sinking step, the ¿o press must operate at high punch speeds, or, as an equivalent„the extruding time must be short. My experience thus far has shown that the most advantageous kresults are obtained by extruding at a punch speed of at least 3 inches per second, 45 or by performing the extrusion proper within 2 or 5 seconds. As a result of the use of high punch speeds, i. e., short extrusion time, the extruded oversize tube will emerge from the press at about the temperature of the billet when inserted into 50 2 2,023,716 - the press, or even somewhat higher in tempera ture,'which suflices to permit it to be subjected to» the extrusion operation. The reducing means shown in the vdrawing comprises a sink mill. vthe reducing, or sinking, Operation without inter mediate reheating. Since the temperature _of the schematically indicated at l5, which operates extruded article depends in part at least, upon upon the oversized and heated tube in the known manner to bring it to the desired external diam- 5 the pressing speed, it is possible,~by suitable reg eter while elongating it'and increasing its wall ulation of the punch speed to the size of billetand thickness somewhat. In the drawing the sized size of extruded article, to regulate, and even in tube is' shown at 6a emerging from the sink crease, within certainV limits, the temperature of mill. ~ the extruded tube, with concomitantadvantage. The invention is especially useful in the pro- l0 duction of articles from metals requiring high` extrusion temperatures, such as steelsand other ferrous metals. Asan example of the invention In the preferred practice ofthe invention as applied to tubes,` the extrusions is conducted to provide a wall thickness approximately the same as that desired in the finished tube, the outer diameter of ¿_ the extruded blank being greater (i. e., ¿ _ oversize) - than lthat ~desired.I _ reference may be made tothe production of _, l -inch` seamless steel tubes.'r According to the l5 extrusion processes as applied heretofore to such duction to size it isthus possible to make long ar- ` purposes such tubes would be produced using ’a ticles from larger billets lwith less mandrel wear mandrel having a diameter of 1118 inch, and a. Bysuch extrusion-of an oversized tube and _re-f matrix die ring having an inner diameter of 1% 20 than would result in extruding the same article to ` inch. These small size to'ols, especially the com- 20 size from a billet of the .same size, soV that mandrel> costs aremateriallyreduced; _In thesinking of,- `paratively thin mandrel, are worn so rapidly in the extruded tube its length is increased, so that" - extruding steel that it is advisable, for reasons , the invention likewise results in the production of economy, to use billets which do not exceed 25 of tubes of greater length than have heretofore »about 40 lpounds in weight. 'Ihe tube extruded been economically producible with the ordinary «from'such a billet and with such tools will be 25 extrusion procedures as> practiced heretofore. about 23 feet long, weighing about 37.5 pounds.` " `Throughgreductio'n of the oversized tube directly" ` In the practice of this invention tubes of the same final 'size are made by extruding a heated _ after extrusion .use is madeof theheat devel 30 oped in the ¿extrusion step,;fso that the reducing _ billet-to form an> oversize tube having an outer diameterî of ‘2% inches and a wall thickness 30 »_ , operation is possible without the intermediate re heatings that have beenunavoidable in the >com monly applied rolling and sinking processes of A y"making seamless tubes, ,such as theL'well-known _Mannesmann or Stiefel processes, as noted here of about 1/8 inch. For a'tube of such size there may befused satisfactorily a billet weighing 104 pounds, which provides an extruded oversize tube 31_feet long. This is directly reduced, with inabove. likewise, the invention furthenreduces out intermediate reheating, toa 1 linch tube, and 35 step combines in one the priorjseparate pierc the tube Willïbe about 6_0 feet'in length.y The “ad- ‘ vantages flowing from the invention will be rec the number of steps required, since the extrusionv v after the sinking operation has been completed , ing and elongating operations, and eliminates the ognized from the foregoing figures. 40 reheating.v The invention Ytherefore overcomes ` 'the economical disadvantagesvof both -procedures A further advantage ofthe process provided 40v Í by this invention resides in the fact that tubes , andr provideszfurther advantagesuover both.” ' 45 ’ ' of ' yvarious f The inventionfsmay be described further with y reference tothe drawing-in which I represents final diameter can be producedfro'm" the same oversize tubes, _i. e., using billetsand, extruding tools of the same size, the only differ rence 'residing in the extent of the reducing, or ß an extrusion -pressfadapted to extrude >tubes rapidly, e.:g.‘ at highy punch‘speeds, as described ïoperation. hereinabove, suitably of the type 'shown in reissue ` sinking, l K llifhen4 changing rthe 'final tube dimension, therefore, adaptation of the re Patent No. 19,474 _to :Fritz Singer, reissued lFeb ruaryv 19, 1935;?15In the form of press'shown'a - ducing mill only is required. For instance, using ,50 billet >2 is disposed., in 'a container‘3 havinga the 2%-inch' extruded tube referred td in the ~ >matrixrdie 4_ atits lower end. The container and foregoing example it is possible to produce all 5° gauges of tubing below 2 inches merely byap y'matrix die are supported ïbya ñxed table 5 pro propriate vadaptation of the reducing mill, or, “ vided With'acentr'ally disposed bore forV egress of the extruded "tube 6». alternatively, by providing several reducing mill through ‘ " 'units.~„ Other advantages will berecognized by A mandrel 'l extends 55 downwardly from a ~ mandrel* carrier 8 those familiar with the art. _' a plunger llî connected lto a hollow plunger >car rier l0 slidably mounted-'inthe upper part of the I' j'press= frame andin which the mandrel carrier moves as a piston, asmay beseen from‘the draw 60 , , According to the provisions of the Patent Stat utes,~I _have explained thefprincipleof my in- I vention, andy have described what I,_now con- ` ing." The plunger and mandrel are actuated’ vsider _to represent its best embodiment. How ever, Iv desire'to have it understood than-within .o -the scope of the appended claims-,the invention through a pitman Il connected at its lower end -to mandrel carrier V8 and at its upper end to' a may be practiced otherwise -than asspecifically ` :crank -|2 driven by a crank shaft I3. The'ex ' truded tube lîemergesffrom the ypress through described. ` l t ~ >the bore in table» 5 and is guided away from the ` ' press by a vchannel‘ïifi. The tubeïöis oversized, byappropriate selec " l. A method `of producing seamless tubes the u greatest sectional width offwhich is not more , tionof'the mandrel and die, relative to the ñnal 'than about three inches comprising piercing a product, and> by vappropriate operation -of the 70 press, -as by lhigh punch, or plungenspeed, -it , emerges in highly heated condition, as_.describ'ed hereinabove. lThe heated tube then passes di ~ rectly,'i. e., 'without intermediate reheating, to » means for hot reducing it lto‘ñnished `size' using . -the heatl inherently in the túber'as a' result oi’ ¿heated 1oversiz'ed'tube, and reducing said tube to desired size utilizing the _residual heat-of ex- " trusion. _ i ' . _ ~ ' »2. A method of producing seamless tubes the greatest sectional width of which is not more than u 3 2,023,776 about three inches comprising piercing a heated billet and extruding the pierced billet through a die at an average punch speed of at least three inches per second to form a highly heated tube having approximately the desired wall thickness but oversized as to external diameter, and reduc ing the article to desiredvsize utilizing the resid ual heat of extrusion. 3. A method of producing seamless tubes the ` l0 greatest sectional width of which is not more than about three inches comprising piercing a heated billet and extruding the pierced billet through a die at an Aaverage punch speed of at least three inches per second to form a. highly heated oversized tube, and subjecting it to a sink mill, utilizing the residual heat of extrusion in the tube, to reduce and elongate the oversized article to bring it to desired size. ADOLF WEFING.