US3287110A - Non-ferrous alloy and method of manufacture thereof - Google Patents

Description

United States Patent 3,287,110 NON-FERROUS ALLOY AND METHOD OF MANUFACTURE THEREOF Paul Joseph Scherbner, Boyertown, Pa., assignor to The Beryllium Corporation, Reading, Pa., a corporation of Delaware No Drawing. Filed May 9, 1962, Ser. No. 193,588 16 Claims. (Cl. 75-129) This invention relates primarily to nickel-base alloys containing beryllium and to a process for producing the same. More specifically, the invention pertains to a new and improved melting procedure whereby nickel-base alloys containing beryllium along with titanium, aluminum, silicon, chromium, boron and zirconium may be produced without resorting to vacuum melting in order to produce ingots or billets for reduction by hot working or by casting. While the present invention will be described in relation to nickel base alloys, it will be understood that the teachings of the invention are equally applicable to cobalt and iron.

In the past, many problems have confrontedthe industry in the formation of nickel-base alloys containing beryllium because of the lack of a suitable, reliable, convenient and inexpensive method, that could be used industn'ally to produce high strength alloy material for engineering applications in relatively large melt sizes.

One of the main problems encountered by persons learned in the art of processing nickel-base alloys containing beryllium, was the occurrence of brittleness at elevated temperatures, of the order of 1200 F. or higher, during hot fabrication whenever the nickel alloys contained beryllium in excess of 1.7 percent and especially when the beryllium content was at 2 percent. Previously nickel-base alloys containing beryllium in excess of 1.7 percent could not be easily fabricated without cracking and without the prior necessity to prepare the alloy by vacuum melting, which is costly.

Because of the limitations in the prior art of melting nickel-base alloys containing beryllium, thecommercial productivity and practical application of the high strength and corrosion-resistant properties of these nickel-base alloys with beryllium has been retarded by a capability of producing only relatively small ingots of less than 50 pound size, and that, only with the aid of a costly vacuummelting procedure.

An object of the instant invention is to produce nickelbase alloys with beryllium for making ingots or billets for reduction by hot-working, as well as for castings without the necessity of vacuum melting.

A further object of the present invention is to set forth an improved process for producing nickel-base alloys containing beryllium in amounts of greater than 1.7% without the necessity of resorting to vacuum melting techniques.

A further object of the present invention is to set forth a process for producing nickel-base alloys containing beryllium wherein by adding certain elements in a specific and critical sequence during the melting operation, the hot workability of the alloy is improved without the necessity of resorting to vacuum melting techniques.

Another object of the instant invention is to introduce greater amounts of beryllium into wrought nickel alloys for strengthening purposes.

Yet another object of the instant invention is to produce a nickel-base alloy containing beryllium which can be easily fabricated without cracking and at the same time having high mechanical properties.

A still further object of the present invention is to produce a nickel-base alloy containing beryllium in amounts of greater than 1.7 percent capable of being hotworked, cold-worked, and capable of developing through 1 suitable heat treatment and precipitation hardening, high mechanical properties.

Yet another object of the instant invention is to set forth a process for making low-carbon nickel-beryllium alloys for east or wrought applications wherein the alloy is capable of obtaining a high degree of hot and cold workability having significantly high tensile strength and hardness, after a precipitation hardening heat treatment.

Another object of the instant invention is to produce a nickel-base alloy which is capable of being cold-worked or formed to shape with ease and then strengthened later by aging.

Other objects and many attendant advantages of the invention will in part be obvious and in part appear hereinafter. For a further understanding of the nature and objects of the invention, reference should be had to the following detailed description.

There is provided by this invention an improved process for producing nickel-base alloys containing beryllium in amounts up to 3 percent, in melt quantities of the order of 500 pounds or more by using conventional industrial melting equipment .without the need of resorting to the more costly procedure of melting under vacuum in order to be able to produce cast ingots or blanks for hot-processing, rolling, extrusion or forging and the like. This process is also suitable for producing high strength, nickel-base alloys containing beryllium with other alloying elements, thatvare to be used in the form of' castings in the heattreated or unheat-treated conditions, or for making ingots for re-melt purposes. pable of being hot-worked, cold-worked and capable of developing through suitable heat-treatment and pre-, cipitation hardening, high mechanical properties.

On the basis of this invention, alloy compositions with significantly high mechanical strength, in the fully heattreated and aged condition, can be made in a wrought or cast condition and processed, consisting of the following elements within the composition ranges indicated in Table l.

The material so produced is ca- With the exception of carbon and sulphur, which are considered to be'undesirable commercial'impurities in the alloys discussed, it is important to indicate the desirable presence in the alloy of small amounts of certain of the above elements, that when added in a specific and im- 5 portant sequence during the melting operation, contribute to improving the hot-workability of non-vacuum melted nickel-beryllium alloys.

Nickel-beryllium alloys containing substantial amounts of elements like titanium, aluminum, and chromium as shown in Table 1, can be melted in electric furnaces in air or preferably under a blanket of argon gas in order to minimize metal loss through oxidation. Illustratively, approximately 500 pounds of pure nickel metal, .to which approximately 1 pound of carbon is added, is melted first-and subjected to a carbon boil by adding nickel oxide powder to the molten nickel containing 0.20 percent carbon at a temperature of about 2800 F. The nickel oxide reacts with the carbon liberating carbon dioxide gases and carbon monoxide- The molten metal isstirred with a pure nickel rod until all reaction ceases, then a slight excess of additional nickel oxide is added. Any nickel oxideadhering to the pot or crucible isremoved. It is, of course, understood that in the event the base melt is otherthan nickel, i.e., cobalt or iron, an oxide of cobalt or iron, as the case may be, would be added to the melt rather than nickel oxide.

Pure silicon metal (approximately 1.5 pounds) in the amount of 0.3 percent is next added to the melt in small pieces and stirred to react and chemically combine with the oxygen in the melt. The reaction between the oxygen and silicon is ended after a short time interval of a few minutes. The reaction product, which is a fluid slag, should be completely-skimmed from the melt surface. 5

The temperature of the melt is maintained at 2600 F. to 2900 F. From this time on, an inert gas blanket is advantageously maintained over the surface of the melt ,until it is cast. The melt is stirred thoroughly once again to raise all the reaction product between the silicon and the oxygen to the surface of the melt for removal before otherelements can be added. Next, 0.5 percent titanium may be added in the form of sponge to fulfill two functions: 1) to chemically'combine with dissolved nitrogen gas that may have been absorbed during melting and to form small solid particles of titanium nitride dispersed through the alloy, and (2) the titanium in excess of that needed to combine with the dissolved nitrogen in order to form isolated particles of titanium nitride, serves to strengthen the alloy later by being 5 available to form a precipitation hardening phase Ni Ti, or if aluminum is also present to formthe compound Ni (Ti, Al). If more than 0.4 to 0.5 percenttitanium is desired in the alloy, then it is added later ;with the nickel-beryllium master alloy. After the addition .015 0.5 percent titanium initially a characteristic surface I listed in the following cited examples.

tion, the alloy compositions and mechanical properties:

film but no slag, is formed on the melt surface. Then, 0.0025 percent boron in the form of '15 percent boron"- nickel master and, 0.025 percent zirconium in the form of pure zirconium sponge are added to the melt to facilitate the hot-working characteristics of the alloy in the temperature range of 1700 to 1900 F. Magnesium, in the form of 10 percent magnesium-nickel master may also be added at the same time to combine with traces of any sulphur present in the alloy.

Up to this point, the alloying procedure has been to properly purify and condition the melt before the last additions of aluminum, chromium, titanium and finally beryllium in the form of percent to percent beryl lium-nickel master alloy. After these additionsare made,

the metal temperature is raised to about 2700 F. and the alloy cast in a manner conventional with good foundry practice.

Many commercial nickel-base alloys without beryllium require substantial amounts of aluminum and titanium, ranging from 0-6 percent aluminum, and 0-4 percent A titanium in order to maximize the age-hardening response.

The addition of beryllium by lowering the solubility of p both aluminum and titanium in the nickel matrix,permits.

smaller amounts of each of these elements to be required to produce maximum strengthening through aging, simultaneously allowing for easier cold deformation in the annealed condition because less solute atoms are in solution. The practical significance of this is realized since I have determined that nickel beryllium strip alloys with 3 percent titanium can be cold-worked with a percent reduction in the area between anneals.

Specific examples of the versatility and capability of my process in producing high strength nickel-beryllium alloys with beryllium contents higher than heretofore claimed capable of being hot-workedor used as castings, without resorting to prior vacuum melting procedures are For simplificaobtained on representative samples of these particular alloys are identifiedby their respective heat numbers.

To indicate the. versatility of the described process-in producing wrought nickel-beryllium alloys with desirable mechanical properties, the alloys are arranged in the following groups:

Group I; Medium beryllium content (Be from 1 to 1.7%) and low titanium content (0 to 1% Ti). Heat No. 69.

Group H: High beryllium (Be from 1.70 to 2%), low

- titanium (Ti from 0 to 1%). Heat Nos..50, 152.

Group III: High beryllium content (Be from 1.70 to 2%) and medium titanium content (Ti from 1 to 2%) Heat Nos. 160, 164.

Group IV: High beryllium content .(Be ranging from.

TABLE II.-COMPOSITIONS OF REPRESENTATIVE ALLOYS USED IN THIS INVENTION, PERCENT Heat N 0. Be Ti Si Al Mg C! B Zr G Ni 0. 0. 23 0 02 0. 024 0. 015 0. 003 0. 03 0. 058 Bal.= 0. 66 0. 31 0 0. 024 0 0. 002 0. 015 0. 010 E81. 0 0. 27 0 27 0. 027 0. 80 0. 003 0. 03 0. 153 Bal. 2. 00 0. 06 O 0. 025 0 0. 003 0. 03 0. 071 Ba]. 1. 80 0. 0 0. 025 0 0. 003 0. 02 0. 020 1381. 3. 06 0. 30 0 0. 029 0 0. 003 0. 05 0. 019 Bal.. 3. 00 0. 31 0 29 0. 030 0 73 0. 003 0. O3 0. 019 1331.. 3. 14 0. 35 0 38 0. 047 0 78 0 0. 055 0. 018 B211. 4. 50 0. 31 0 0. 028 0 0. 003 0. 03 0. 21 B211.

TAB LE III Heat No. A* At H HT SH SHT Ultimate Tensile Strength x 1000 a. 69 86 m I011 Gmug 11 211 153 2% i 5?? 1 1 155 Gmup m 164 229 174 47 129 236 168 Group IV g: 133 322 197 Group v. 109 231 197 Yielgr StrenIgth (0.2% ofiset) x 1,000 p.s.i.: 69 34 143 roup 50 as 155 H 15 2 :4 1;: 12s 16 7 1 1 5 Group In 154 48 169 15s 47 62 158 159 Group IV g2 62 184 Group v 109 62 185 Note:

A=Annea1ed, hour at 1,9100 F., and water ouenched. AT=Annealed, water quenched, and aged, 5 hour at 1,000 F. H =A11nealed, water quenched, cold-rolled 37% HT=Annealed, water quenched, cold-rolled 37 aged hour at 1,000 F.-

SH=Annea1ed, water quenched, cold-rolled 62%.

SHT=Annealed, Water quenched, cold-rolled 62%, aged hour at 1,000 F.

TABLE IV Heat No. A At 11 HT s11 SHI Proportional Limit (0.01% offset) x 1,000 psi:

a a 12s 1 111 Group H 129 118 145 111 as GmuP 1H l 154 as 109 117 12a 47 as 133 127 172 133 210 Group IV 48 34 136 127 176 124 199 as 115 114 198 Group v 109 37 122 132 17s Elongation, percent:

GwupI 23 g i i 2 11 GIMP H 152 21 1 12 a 5 Group III i2; 31 g i r 47 as 15 5 s 1 4 4s 2s 15 4 1o 1 7 as 15 s 2 3 109 32 20 2 11 TABLE v Heat No; A At H HT 8H SHT Rockwell:

------------ a as so 5 5 a as m 164 71B 510 38C 560 III:

47 89B 490 380 54c 430 55c GroupIV 48 90B ,480 400 540 43c 550 as 500 54c 450 560' Group V- 109 83B 1 46C 42C 53C The .alloys illustrated in the above examples show a lower yield strength and hardness in the annealed and cold-rolled condition than when aged; This is desirable in many applications and permits the alloys to be coldworked or formed to shape with greater ease, then strengthened later by the aging treatment.

The addition of from 0.50 to 4.50 percent titanium and from 1 to 2 percent beryllium produces an alloy which not only has high hardness afiteraging, good elongation, high yield strength, but also good formability in the annealed condition. Also, the addition of 0.66% titanium to a nickel-base alloy containing 2% beryllium, can be produced by the disclosed process with resultant invention is defined by the appended claims, all changes- Thus, by making use of the present invention, the alloys.

that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are therefore intended to be embraced excellent fabricability as distinguished from the prior art. 75 by those claims. I

7 I claim: 1. A method of producing a nicke1 base alloy containing beryllium which comprises the steps of (1) melting said base metal in the presence of a quantity of carbon; (2) adding to the resulting melt a quantity of an oxide of said base metal to cflect a first purification; (3) adding .to said first purified melt a de-oxidizing 'agent suflicient to react and chemically combine with the oxygen of said melt; (4) removing from the melt the reaction product of the de-oxidizing agent and oxygen thereby effecting a second purification of the melt; and (5) adding to the melt the elements titanium, zirconium, aluminum, chromium and beryllium.

. Percent Beryllium 0.6-3.0

Titanium 0.0-4.5 1 Silicon 0.0-1.0 Aluminum 0.05-2.5 Magnesium 0.01-0.05 Chromium 0.0-1.50 Boron 0.0-0.005 Zirconium 0.0-0.05 Nickel,

2. A method of producing a cobalt base alloy con- I taining beryllium which comprises the steps of v 1) melting said base metal in the presence of a quantity of carbon;

(2) adding to the resulting melt a quantity ofan oxide of said base metal to effect a first purification;

(3) adding to said first purified melt a de-oxidizing agent sutficient to react and chemically combine with the oxygen of said melt;

(4) removing from the melt the reaction product of the de-oxidizing agent and oxygen thereby efiecting a second purification of the melt; and

(5) adding to the melt the elements titanium, zirconium, aluminum, chromium and beryllium.- 3. A method of producing an alloy containing beryllium and having as its base a 'metal selected from the group consisting of nickel, cobalt and iron, said method comprising the sequential steps of (1) melting said base metal with a quantity of carbon; (2) adding to the resulting melt a quantity of an oxide of said base metal suificient -to react therewith and cause the evolution of carbon dioxide and car- 'bon monoxide thereby effecting a first purification;

(3) adding to said first purified melt a quantity of silicon suffioient to react and chemically combine with the oxygen 01f said melt;

(4) removing -from the melt the reaction product of second necessity to prepare the same by vacuum melting, said alloy consisting of the following elements:

9. A nickel base alloy adapted 'to being produced with:

10. A nickel base alloy adapted to being produced without resorting to vacuum melting, consisting of:

. Percent Beryllium 1.91 Titanium .66 Silicon .31 Magnesium .024 Boron .002' Zirconium .015:

Nickel, balance.

11. A nickel base alloy adapted to being produced without resorting to vacuum'melting, consisting of:

Percent Beryllium 2.08 Silicon .27

Aluminum .27 Magnesium -027 Chromium .80

Boron p .003 Zirconium .03

Nickel, balance.

12. A nickel base alloy adapted to being produced 5 without resorting to vacuum melting, consisting of? 5. A method of producing an alloy containing beryl lium as set. forth in claim 3, wherein the base metal is cobalt and wherein the oxide added in step ('2) is an oxide of cobalt.

' 6. A method of producing an alloy containing beryllium as set forth in claim 3, wherein the base metal is iron and wherein the oxide added in step (2) is an oxide of iron.

-7. A method of producing an alloy as defined in claim 3, wherein the ratio of addition of the carbon and silicon is approximately 1 pound carbon, one and a half pounds of silicon, "and 500 pounds of base metal and wherein the temperature of the melt is maintained between about 2600 F.--to 2900 F.

8. A nickel basealloy characterized by its susceptibility to fabrication without cracking and without the prior Percent Beryllium 1.71 Titanium 2.00

. Silicon .06 Magnesium 0.025 Boron .003

Zirconium .03

'Nickel, ba-lancc.

1 3. A nickel base alloy adapted to being produced Nickel, ba an e;

9 14. A nickel base alloy adapted to being produced without resorting to vacuum melting, consisting of:

Percent Beryllium 1. 67 Titanium 3.06

Silicon .30 Magnesium 0.29 Boron .003 Zirconium .05

Nickel, balance.

15. A nickel base alloy adapted to being produced without resorting to vacuum melting, consisting of:

Nickel, balance.

.10 16. A nickel base alloy adapted to being produced without resorting to vacuum melting, consisting of:

Percent Beryllium 1.74

Titanium 3.14

Silicon 0.35

Aluminum 0.38

Magnesium 0.047

Chromium 0.78

Zirconium 0.055 Nickel, balance.

References Cited by the Examiner UNITED STATES PATENTS 1,941,368 12/ 1933 Smith 170 2,062,130 11/ 193 6 Hessenbnuch 75l70 2,829,048 4/ 195 8 Cocha-rdt 75--171 3,180,726 4/1965 Nakamura 75129 OTHER REFERENCES The Making, Shaping and Treating of Stee Seventh edition, pages 352 353, published by United States Steel Corp.

DAVID L. RECK, Primary Examiner.

MAROUS U. LYONS, HYLAND BIZOT, Examiners.

R. O. DEAN, H. TARRING, Assistant Examiners.

Claims (2)

1. 3. A METHOD OF PRODUCING AN ALLOY CONTAINING BERYLLIUM AND HAVING AS ITS BASE A METAL SELECTED FROM THE GROUP CONSISTING OF NICKEL, COBALT AND IRON, SAID METHOD COMPRISING THE SEQUENTIAL STEPS OF THAN 2.3 ATOMIC PERCENT CHROMIUM WITH THE REMAINDER (1) MELTING SAID BASE METAL WITH A QUANTITY OF CARBON; (2) ADDING TO THE RESULTING MELT A QUANTITY OF AN OXIDE OF SAID BASE METAL SUFFICIENT TO REACT THEREWITH AND CAUSE THE EVOLUTION OF CARBON OXIDE AND CARBON MONOXIDE THEREBY EFFECTING A FIRST PURIFICATION; (3) ADDING TO SAID FIRST PURIFIED MELT A QUANTITY OF SILICON SUFFICIENT TO EACT AND CHEMICALLY COMBINE WITH THE OXYGEN OF SAID MELT; (4) REMOVING FROM THE MELT THE REACTION PRODUCT OF THE SILICON AND OXYGEN THEREBY EFFECTING A SECOND PURIFICATION OF THE MELT; (5) ADDING UP TO 0.5% TITANIUM TO THE MELT TO COMBINE WITH ANY NITROGEN GAS PRESENT TO FORM TITANIUM NITRIDE; (6) ADDING APPROXIMATELY 0.0025% BORON; (7) ADDING APPROXIMATELY 0.0025% OF ZIRCONIUM IN THE FORM OF PURE ZIRCONIUM SPONGE; (8) FINALLY ADDING TO THE MELT THE DESIRED ADDITIONAL ALLOYING ELEMENTS INCLUDING BERYLLIUM.
2. 8. A NICKEL BASE ALLOY CHARACTERIZED BY ITS SUSCEPTIBILITY TO FABRICATION WITHOUT CRACKING AND WITHOUT THE PRIOR NECESSITY TO PREPARE THE SAME BY VACUUM MELTING, SAID ALLOY CONSISTING OF THE FOLLOWING ELEMENTS: