US1993600A - Drawn article and process of making the same - Google Patents

Description

Patented Mar. 5, 1935 UNITED STATES PATENT OFFICE 1,993,600 DRAWN ARTICLE AND PROCESS OF MAKING THE SAME Hugh John Fraser, Kenyon Jenckes, Huntington,

Owens, Edwin New York,

No Drawing. Application February 18, 1933, Serial No. 657,466

21 Claims.

The present invention relates to drawn articles made of malleable metals or alloys and more particularly to an improved wire, tubes, rods and the like, especially when 1% constituted of malleable nickel-containing material, particularly alloys containing nickel and chromium.

It is an object 01' the present invention to provide an improved process for producing drawn 10 articles without intermediate annealing after the various drawing operations.

It is a further object of the invention to provide a process of producing drawn articles involving an initial heat treatment in a hydrogen- 75 containing atmosphere to impart unique characteristics to the product being drawn.

It is another object of the invention to provide an improved process for drawing wires, tubes, rods and the like which is capable of drawing the initially annealed product to its final size without subsequent annealing treatments.

It is also within the contemplation of the invention to provide a process of drawing wire which is capable of being operated in a continu- 125 ous manner.

It is still a further object of the present invention to provide a method of heat treating a hot rolled rod or wire rod by annealing in a hydrogen-containing atmosphere, lead coating 30 without pickling, and drawing the initially annealed product to its final size without subsequent annealing treatment.

Another object of the invention is to provide an improved process of drawing articles in which 85 heavier or greater reductions per pass may be is produced, in which a decreased cost of die maintenance and replacement is effected, and in which a superior quality of finished product is obtained.

A still further object of Other objects and advantages of the invention will become apparent from the following description:

It has been discovered that products, particularly nickel and nickel alloys, when given a spe- 5 cial initial heat treatment in a hydrogen containing atmosphere and then coated with lead without pickling, the product can be drawn to the final desired condition without intermediate annealing and the like. Thus, for instance, by the use of the present invention, it has been possible to draw a nickel-chromium wire rod having a diameter of about to a fine nickel-chromium wire having a size of about 0.001 inches. Heretofore, it has absolutely been impossible to acl5 complish such a procedure.

Broadly stated, the invention contemplates an initial heat treatment in a hydrogen-containing atmosphere, the temperatures ranging from about 1200 F. to about 2200" F. depending upon the constitution or the nickel content of the material under treatment. It is essential to use a reducing gas for the atmosphere which is substantially It has been found that the hydrogen content of the atmosphere can be varied depending upon the metal or alloy under treatment and particularly the nickel content thereof.

The article which is subjected to the initial heat treatment in a hydrogen-containing atmosphere is maintained at such a temperature for a sufiicient length of time to practically insure a metallic condition substantially throughout the surface skin. As yet, it has not been definitely ascertained what this special initial heat treatment in a hydrogen-containing or reducing atmosphere does to the article under treatment but it is definitely known that the metallic surface and the metal are converted into such a condition that upon direct lead coating,the article can be drawn to a fine wire or a small tube or a small rod without intermediate annealing. Results of this character have been unknown in the art (1 it has only been possible to draw certain nickel alloys such as nickel-chromium alloy and the like by repeated intermediate annealing and by a very complicated, cumbersome and expensive proce-' Typical of such prior procedures is one described by W. H. Wills and J. K. Findley on pages 97 to 114 in the August, 1932, issue of The Transactions of the American Society for Steel Treating. In this. article the authors described the manufactur properties and use of 18-8 chromium-nickel steel wire and discuss the necessity of annealing or heat treating the drawn or worked wire and then pickling the same in acid before further drawing or working operations can be carried out. In this connection, the authors state of chromium-nickel steel wire that:- When subject to cold working it rapidly develops increased hardness making frequent heat treating necessary."

After lead coating the excess of lead is removed by means of a wiper or the like. In practice, it has been found to be essential to apply the lead as a uniform layer or coating. when precautions are taken to insure the application of a uniform coat of lead, a product is produced which is substantially free from non-uniformity or variations. In passing, it might be mentioned that any appropriate procedure may be used to of lead and to remove the excess those skilled in the reductions, it is not necessary to subject the drawn article to annealing which was heretofore an indispensable operation. It has been found that repeated drawings may be employed and the article drawn to practically any desired commercial and industrial size without intermediate annealing or heat treatment.

When tubes are being drawn it has also been found that superior results can be obtained by using a rotating mandrel. The drawing of chromium-nickel tubes has been greatly facilitated by use of the rotating mandrel. Of course, conventional methods may be employed but it is preferred in carrying the present invention into practice, to employ the rotating mandrel. The mandrel is supported by appropriate means at each end thereof. At one end, the mandrel has secured thereto driving means such as a gear. This gear is connected to a prime mover, such as an electric motor by means of a suitable train of gears like a gear reducer.

, After the article has been given the required number of passes to reduce the article to the desired size, it is possible to employ the article in the drawn condition. A fine film or coating of lead still remains on the surface of the wire, tube or rod and in many cases this lead film or coating is not objectionable. In those cases where it is desired to have a deleaded surface, the film or 5 coating of lead may be stripped off the surface of the article by means of an appropriate acid or the like such as a 540% solution of nitric acid. If desired, the deleaded wire, tube or bar may be given a finishing pass or passes to impart an improved or desiredsurface to the article.

For the purpose of giving those skilled in the art a better understanding of the invention the following specific and illustrative examples are given:

Example N o. 1

A'hot rolled chromium-nickel alloy rod having a diameter and containing approximately 14% of chromium and per cent of nickel was continuously annealed in a reducing atmosphere containing hydrogen in an electrically heated furnace at about 1950 I". The thus treated wire is coated with the uniform envelope of lead in any appropriate manner. In practice, it is preferred to pass the strand of wire through a molten bath of flux which is floatingupon a molten bath of lead. The wire is carried through the molten layer of lead and then out of the bath at a point which is free from hurt. The lead coated wire is cooled and is then rolled into a coil. The flux may be any suitable composition but it was found that fiux containing zinc chloride (8 parts by volume), sodium chloride (4 parts by volume) and ammonium chloride (1 part by volume) functions very satisfactorily and provides a surface which can be effectively lead coated. In the operation of the lead bath a temperature of about F. to about 800 F. and preferably 720 1''. to about 750 F. is maintained. As a result of experiments, it has been found that the lead does not have to be a pure lead but may contain impurities such as antimony, etc.

When wire is being leaded in the form of a strand, it has been found advisable to run the strand through a wiper to remove any excess of lead. In the event that the wire is leaded in coils, the latter are preferably rolled over and over in the bath to insure thorough wetting by the fiux before introducing the coils into the layer of molten lead. The coils may be passed through the molten lead and then removed from the bath to permit the lead to solidify. It is preferred to throw the coils on the floor and shake them up and down until the lead has solidified, thus, preventing the strands from sticking together. In any case, it is important that the entire surface of the wire be covered with a tenaciously adhering coat of lead which is preferably as uniform as possible.

The lead coated wire is drawn through wortle dies. The amount of reduction per pass may be in excess of 35%. Thus, in the appended Table I, the passes are given with the percentage of reduction and the diameter of the wire. In addition, the breaking strength is given in pounds per square inch. In the table the elongation is given in percent per 2" and the reduction of area is given in percent.

Table N 0. 1

- Percent Break- Redue Pass No. 2: redueing 335 tion of tion strength area 50. 0 157, 000 6. 0 56. 4 68. 3 173, 400 5. 0 43. 5 82.9 183, 500 3. 5 30. 4 90. 0 207, 500 2. 5 Ki. 0 93. 7 213, (XX) 2. 0 45. 7 96. 0 212, (D0 2. 0 45. 2 97. 6 218, 000 l. 5 31. 4 98. 4 241, 500 98. 6 217, 000 98. 8 225, 000 99. 2 245, 000 99. 3 246, 300 99. 4 245, 000 99. 5 232, 000 15 012 99. 7 (II) The aforesaid alloy was not drawn smaller than .012" diameter at which point its tensile strength was greater than 200,000 psi. It could have been drawn to finer sizes.

After cold drawing, the thin coating of lead remaining on the wire was removed by dipping the wire in a 10% solution of nitric acid.

1". diame .wasbright annealed at a te 17502-1. in a natural gas atm approximately 3.5 percent wasthen lead coated with coated rod was drawn an percentage of reduction,

This represents a tot over 99.9 percent wit duced a tensile streng al reduction of area of out annealing and proth in the wire of over Adhering lead by dropping in The wire was then w n the drawn wire w solution of nitric acid. ashed and dried in the Example N0. 3.

A diameter hot re (30% nickel, 62% rod was annealed in a gas fired ducing atmosphere at about 19 rod was then lead coated and dr .140" diameter with approxima duction in area per pass.

It will be observed made it possible to m pass. For comparative p to be impossible without this wire to the same deg nealed after at least ever drawing of the wire for wortle dies and soap in accordance with prior art For the removal of lead r a 10% nitric acid solution lied modified Elinvar chromium) wire furnace with re- F. The wire awn to about tely 40% reiron and 8% that the present process heavy reductions per urposes it was found lead coating to draw ree unless it were .any second pass. In the comparative purposes, ricant were used in emaining on the wire,

Example No. 4

hot rolled wire rod of both pure nickel were annealed in at 1700-2000 F. olution containing apm phosphate and 7 perwas lead coated without Monel metal and a reducing atmosphere at abo and then washed in a s proximately 3% tri-sodiu cent soda ash. The wire pickling and was dra The lead coated wir with considerable less wires and gave a superior example, the tensile ucts at .012"

es drew much easier and tching than uncoated finished product. For properties of the final proddiameter were as follows:

Breaking strength Monel metal Chrome-nickel alloy 000 (psi.) lbs. per sq. in. 000 (psi.) lbs. per sq. in. ,000 (psi.) lbs. per sq. in.

1,9os,eoo

' Example N0. 5

A chromium-nickel wire rod is annealed and q .100 and .077" diameter at the successive dies.

.',Ihe'.077" wire is then transferred to a continuous draw bench using 12"-16 blocks and .drawn through 5-6 metallic carbide dies successively, with 40-20% reductions per pass and finishing at approximately .027" diameter. As

the wire becomes finer, the reduction per pass is decreased slightly. The sizes of wire at the intermediate dies on a 5 die. bench are .059", .045", .036", .031" and .027" diameter.

The .027" wire is then transferred to a continuous draw bench using t'en 6-8" blocks and drawn through diamond dies successively with approximately 20% reductions per pass. Metallic carbide dies may be substituted for more of the larger sizes of diamond dies. The sizes of wire at the intermediate stages on a 10 die bench are .025", .022", .020", .018", .016", .014", .0126". .011, .010 and .009" approximately. A similar procedure is used to reduce wire to sizes of .003" and smaller.

6-8" 5003,500 it. per min Wet soap or oil solutions.

' Example No. 6

On the final finishing pass when drawing chromium-nickel tubes after the lead coating has been removed, scratching of the inside of the tubes is difiicult and almost impossible to overcome by conventional drawing methods. It has been found that the substitution of a rotating mandrel, as noted hereinabove instead of the stationary mandrel, overcomes this drawing difficulty to a large extent and results in lower operating costs, less scrap, decreased loss of time for maintenance and repair, and a better surface quality of finished product.

It will be observed that the present invention provides a process which is capable of making total reductions greater than about 99+ It will also be noted that the present invention provides a process which is capable of reducing rods having a diameter of say 5" to smaller rods having a diameter of say 4" and smaller to about Furthermore, it is to be noted that the present invention provides a process for drawing wire from rods having a diameter of about 1 to wires having a smaller diameter of say and smaller to 0.003"-0.000'5-f.' and even to 0.001" or less without any intermediate annealing.

Moreover, it is to be observed that the present of a variety of sizes including tubes originally having an outside diameter of 8 with a shell having a. wall thickness up say about and that by subjecting such shells to the present procedure smaller tubes with various wall thickness can be produced by subjecting the shell to a plurality of passes say up to 12 passes or more without any intermediate annealing.

The present invention. provides an improved process for the continuous or intermittent manufacture on an industrial scale of commercial cold drawn products such as rods, tubes or wire and for the manufacture of the foregoing products at faster speeds, greater reductions per pass in cold working without intermediate annealing and lower operating costs.

It will also be observed that the present invention provides a process which is especially useful in conjunction with the commercial manufacture of products made from hard alloys such as nickel alloys containing chrome, copper, manganese, aluminum, etc. which have heretofore been difhcult to handle commercially and industrially because it has not been possible with prior processes to coordinate a series of heat treatments and mechanical operations and conditions and to permit continuous cold. working of a product to finished size without intermediate annealing.

It will be further. noted that the present invention provides a process of lead coating and drawing a hot rolled product without the customary .the same in a substantially pickling and without the necessity of usual amalgamation and without the prior intermediate annealing. With the new process a lead coating may be applied to the surface of the product under treatment and the applied lead coating will remain intact during the drawing operations and will provide a surface skin and bond with the base metal that the friction between the die and the metal being drawn is greatly reduced and the conditions are such as to permit the metal to be drawn faster with greater reductions per pass without annealing and with less scratching of the metal and of the dies and with total reductions in area of over 99% of the original size.

What is claimed is:

l. The process of manufacturing a drawn product which comprises heating a metallic product in a reducing atmosphere, enveloping the thus heated product in a leaden coat devoid of mercury amalgam and drawing the lead coated product to desired size without intermediate annealing.

2. The process of manufacturing a drawn metallic product which comprises annealing a metallic product in a reducing atmosphere substantially devoid of moisture and oxidizing gases, enveloping the thus heated product in a leaden coat without pickling, and drawing the lead coated product without annealing, said drawing being effected by reductions in excess of 35%.

3. The process of manufacturing a drawn metallic product which comprises heating a metallic product in a reducing atmosphere containing hydrogen, enveloping the thus heated product without pickling the same in a leaden coat, and drawing the product without intermediate annealing and by reductions in excess of 35%.

4. The process of manufacturing a drawn metallic product which comprises heating a metallic product in a reducing atmosphere devoid of moisture and oxidizing gases to a temperature in excess of about 1200 F. and not higher than about 2200 F. for a period of time, enveloping the thus heated metallic product without annealing uniform leaden coat, and subjecting the thus coated product to a plurality of drawings without intermediate annealing, each of said drawings involving a reduction in excess of 35%. v

5. The process of manufacturing a drawn metallic product which comprises heating a metallic product in a reducing atmosphere substantially I ling the same,

free from mqisture and oxidizing gases and containing hydrogen at a temperature in excess of about 1200 F. to 2200' F. for a period of time, envelopingv the thus heated product without pickling in a leaden coating, and drawing the product to desired size without intermediate annealing and by a plurality of reductions inexcess of 35%.

6. The process of manufacturing a drawn metallic product which comprises passing a metallic product through a reducing atmosphere containing hydrogen, subjecting the metallic product to electrical heat at a temperature of about 1200 F. to about 2200" F. for a period of time, envelopthe thus heated product without pickling in a leaden coat, subjecting the lead coated product to a plurality of drawings without intermediate annealing, each of said drawings being in excess of 35%. I

'1. The process of manufacturing a drawn metallic product which comprises heating a metallic product in a reducing atmosphere containing a high concentration of hydrogen at a temperature of about 1200 F. to about 2200" F. for a period of time, applying flux to said body, enveloping the flux product in a leaden coating, and drawing the product to desired size without intermediate annealing, said drawing involving reductions in excess of 35%.

8. The process of manufacturing a drawn metallic product which comprises heating a metallic product in a reducing atmosphere substantially devoid of moisture and oxidizing gases and containing hydrogen at a temperature of about 1200 F. to 2200 F. for a period of time, applying molten flux to the heated product without pickling the same, applying a leaden coat to said fluxed product, removing excess of lead to produce a substantially uniform coat and drawing the product to desired size without intermediate annealing said drawing involving reductions in excess of 35%.

9. The process of manufacturing a drawn metallic product which comprises continuously heating a metallic product in a reducing atmosphere substantially devoid of moisture and oxidizing gases and containing hydrogen to a temperature of about 1200 F. to 2200 F. for a period of time, applying molten flux to the thus heated product without pickling the same, immersing the fluxed product in a leaden bath at a temperature of about 700 F. to 800 F., removing excess of lead from said product to produce a substantially uniform coat and continuously drawing the product without intermediate annealing, said drawing involving reductions in excess of 35%.

10. The process of manufacturing a drawn metallic product which comprises heating a metallic product in a reducing atmosphere substantially devoid of moisture and oxidizing gases and containing hydrogen at a temperature of about 1200 F. to 2200 F. for a period of time, applying molten flux to the heated product without pickaDDlyin a leaden coat to said fluxed product, removing excess of lead to produce a substantially uniform coat, drawing the product to desired size without intermediate annealing, said drawing involving reductions in excess of 35%, and subjecting the drawn product to the action of nitric acid-to remove the leaden coating remaining on the surface of the product.

11. The process of manufacturing a drawn metallic product which comprises heating a metallic product containing nickel and chromium in a reducing atmosphere substantially devoid of moisnickel-containing product including 1,998,600 'ture and oxidizing gases and containing hydrogen to a temperature in excess of about 1700 F. for a period of time, enveloping the heated product containing nickel and chromium without pickling the same in a substantially uniform leaden coat, and drawing the product to the desired size without intermediate annealing by the use of a plurality of reductions in excess of 35%.

12. The process of manufacturing a drawn wire, tubing and the like which comprises heating a nickelcontaining product in a reducing atmosphere, enveloping the thus heated product in a leaden coat devoid of mercury amalgam, and drawing the lead coated product to desired size without intermediate annealing.

13. The process of manufacturing a drawn nickel-containing wire which comprises annealing at nickel-containing product in a reducing atmosphere substantially devoid of moisture and oxidizing gases, enveloping the thus heated product in a leaden coat without pickling, and drawing the lead coated product without annealing to produce a wire, said drawing being effected by reductions in excess of 35%.

14. The process of manufacturing a drawn nickel-chromium containing product including wire, tubing and the like which comprises heating a metallic product containing nickel and chromium in a reducing atmosphere containing hydrogen, enveloping the thus heated nickel-chromium product without pickling the same in a leaden coat, and drawing the nickel-chromium product without intermediate annealing and by reductions in excess of 35%.v r

15. The process of manufacturing a drawn nickel-chromium containing wire' which comprises heating a metallic product containing nickel and chromium in a reducing atmosphere devoid of moisture and oxidizing gases to a temperature in excess of about 1200 F. and not higher than about 2200 F. for a period of time, enveloping the thusheated nickel-chromium containing product without annealing the same ina substan-- tially uniform leaden coat, and subjecting the thus-coated product to a plurality of drawings without intermediate annealing to produce a nickel-chromium containing wire, each of said drawings involving a reduction in excess of 35%.

16. The process of manufacturing a drawn nickel chromium containing product including wire, tubing and the like which comprises continuously heating a nickel-chromium containing product in a reducing atmosphere substantially devoid of moisture and oxidizing gases and con taining hydrogen to a temperature of about 1200" F. to 2200 F. for a period of time, applying molten flux to the thus heated nickel-chromium contain ing product without pickling the same, immersing the fluxed product in a leaden bath at a temperature of about 700 F. to 800 F., removing excess of lead from said product to producea substantially uniform coat, and continuously drawing the nickel-chromium containing product without intermediate annealing, said drawing involving reductions in excess of 35%.

17. A metallic product having a gas reduced surface covered by a lead coating and capable of being drawn without intermediateannealing.

18. A metallic product having a gas reduced surface covered by a lead coating and capable of being drawn without intermediate annealing by a plurality of reductions in excess of 35%.

19. A metallic product including wire, tubing and the like having a gas reduced surface covered by a lead coating and capable of being drawn to a wire, tubing and the like without intermediate annealing.

20. A nickel-containing product having a gas reduced surface covered by a lead coating and capable of being drawn without intermediate annealing.

21. A nickel-chromium-containing product having a gas reduced surface covered by a lead coating and capable of being drawn without intermediate annealingr HUGH JOHN FRASER. ROBERT JOHN OWENS. EDWIN KENYON JENCKES. JOHN COULTER LENHART.