US2255895A - Workable nickel and nickel alloy - Google Patents

Description

lated elements Patented Sept. 16, 1941 WORKABLE. NICKEL AND NICKEL ALLOY Leonard Bessemer Pi'eil, Edgbaston, Birmingham, England, assignor to The International Nickel Company, Inc., New of Delaware York, N. Y., a corporation No Drawing. Original application October 6,

1936, Serial No. 104,179. Divided and this application April 25, 1939, Serial No. 269,912. In Great Britain October 15, 1935 6 Claims.

The present invention relates to nickel and nickel alloy's having improved workability and products made therefrom including electric resistance units.

Nickel and its alloys have, in some cases, been somewhat diificult to work and under certain circumstances an alkaline earth metal has often been added to the molten materials. In order to obtain the full benefits of the addition of the alkaline earth, it is desirable to add more of the alkaline earth metal, calcium' for example, than is consumed by the desired chemical reactions. This results in a residue of calcium or other alkaline earth in the finished material (or a residue of some other element reduced from the furnace lining, slag, and so forth, by the excess calcium, etc.), but it is important to control the amount of alkaline earth metal that is left as the presence of more than a certain amount of calcium or other alkaline earth metal makes the material unworkable.

I have made the surprising discovery that the necessity for strict control of the amount of calcium or other alkaline earth metal can be avoided and, yet the materials can be rendered easily workable.

It is an object of the present invention to provide nickel and/or nickel alloys having improved workability.

It is another object of the present invention to provide means for obviating the need for extreme care in regulating the amount of alkaline earth metal added to nickel and/or nickel alloys. It is a further object of the present invention to compensate for the excess of alkaline earth present in a nickel and/or nickel alloy material by the addition of a regulated, critical amount of another element usually considered deleterious.

The present invention also contemplates the production of nickel alloys particularly suitable for use as electrical resistance units.

Other objects and advantages will become apparent from the following description.

In general, the present invention contemplatesmelting nickel and/or nickel alloying metals in the usual manner followed by the usual deoxidizing, desulfurizing, etc. The deoxidizing, desulfurizing, etc., may be carried out by the addition of calcium silicide or other alkaline earth metals or alkaline earth metal alloys, or by means of aluminum, cerium and re- (including thorium, hafnium,

metal is left in the finished material, and sim-' ilarly more than one of the metals usually considered deleterious may be added.

-It is convenient to describe the nature of the present invention in connection with calcium and arsenic, but it is to be understood that these may be replaced respectively by other alkaline earth metals and other elements of group V, i. e., phosphorus, antimony and bismuth.

The amount of calcium and the accompanying arsenic to be added to the melt varies according to the working conditions, i. e., the type of furnace, conditions of the lining, the speed of melting, the nature of the raw materials, and other similar factors, but in order to give an indication of the relative amounts of calcium and arsenic, it may be stated that when between about 0.05 and about 0.15% calcium is present in the finished material that may advantageously be accompanied by about 0.01 to about 0.05% arsenic. In general, it is preferred so to carry on the process that small quantities of calciumand an element of group V remain in the finished material because in this way,'it can be ensured that the beneficial effectsobtained by their addition to the molten material are produced to the full. The preferred ranges are as follows:

Per cent Per cent Element: by weight Element: by weight Calcium"- 0.01 to 0.10 Phosphorus 0.01 to 0.06 Calcium--- 0.01 to 0.15 Arsenic 0.01 to 0.2

Calcium--- 0.01 to 0.2 Antimony 0.01 to 0.25

In the case of bismuth, not more than about 0.075% should be added.

As is well known,.the calcium may be added as a metal or as an alloy or compound, such as calcium silicide and the group V element may be added in the elemental form or as an alloy or compound, such as, for example, nickel arsenide or calcium phosphide. The alloying process may be carried out in any suitable manner. Thus, a preliminary addition, ofv calcium silicide may be made to the melt and any substantial excess of calcium removed by oxidation. A final calcium silicide addition may be made just before casting. The less oxidizable of the group V elescandium, yttrium, and zirconium); and manme ts ay be a ded at a y stage n t e me ting process, or may be added in a suitable alloyed form with the cold charge.

The additions may be made by plunging the elements or alloys to the bottom of the molten metal by any suitable means so as to improve thealloy-, ing process. The group V elements together with part or all the'calcium, or other alkaline earth metal, may, however, be added to the molten stream duringv the pouring of the metal. I

For the purpose of giving those skilled in the art a better understanding of the present invention, the following examples are given by way of illustration.

Example No. 1

a In the production of the well known, 80/20 nickel-chromium alloy according to the present invention, the following procedure may, for example, be followed:

About 800 pounds of nickel are melted and subjected to deoxidation by the addition of. about 0.25 to about 0.5% manganese and about 0.25%

silicon, about-200 pounds of chromium are added and when the mass is molten, about 6 pounds of calcium silicide containing about 25% calcium are added. This is equivalent to adding-about 0.13% calcium to the melt. When suflicient time has been allowed for the desired reactions to proceed and the temperature of the metal hasbeen adjusted'to that correct for casting, the metal is poured into a'ladle, and about 0.5 of a pound of metallic arsenic is added thereto. About 1 pound of calcium silicide is introduced into the ladle, and the metal is cast. These last additions represent about 0.045% and about 0.08%, respectively, of the total mass.

Example No. 2

nickel, the following example is given:

About 1000 pounds of commercial nickel are melted together with about 0.25% manganese and about 0.1% silicon. When molten, the metal is poured into the ladle and during the pouring operation, an addition of about 0.025% arsenic is made followed by about 0.05% calcium either in the metallic form or in the form of calcium silicide.

In the application of the present invention to the preparation of iron-nickel alloys, the following example is presented for illustrative purposes:

. Example No. 4

In the production of 50-50 nickel-iron alloy,

about 500 pounds of nickel and about 500 pounds of iron are melted together with about 0.25%

manganese and about 0.1% silicon. ,When molten, the metal is poured into the'ladle and during the pouring operationan addition of about 0.025% arsenic is made followed by the addition of about 0.05% calcium either in the metallic form or in the form of calcium silicide.

. made.

- electrical resistance alloys are also known as high particular advantage to those nickel-chromium and nickel-chromium-iron alloys from which, as a general rule, electrical resistance elements are As those skilled in the art know, such temperature resistance alloys, high resistance alloys, and the like, and include such alloys as'are available for use at elevated temperatures in excess of 500 C. Those skilled in the art have classified the nickel-containing alloys in, two groups. For instance, Hunter and Jones in an article entitled "Some electrical properties or high-resistance alloys, in the Proceedings of the American Society for Testing Materials, volume 24, 1924, part 11, page 401, referred to both the nickel-chromium alloys and the nickel-chromium-iron alloys. Hunter and Jones stated that binary nickel-chromium alloys containing up to 30% chromium had been made and that the commercial alloys usually contained 15% to 20% chromium; The authors also stated that a well known nickel-chromium-iron alloy contained about 60 nickel, 26% iron, and 12% chromium, while another contained less iron and more chromium. It was also pointed out that many of the alloys were worked under the Marsh patent. The Marsh United States Patent No. 811,859 of 1906 disclosed the use of nickel-chromium alloys for electric resistance elements. Marsh's alloys contained over 50% nickel or cobalt, or both, and less than 50% chromium, but preferably contained less than 25% chromium and more than 75% nickel. As examples, the 90/10 and 85/15 nickel-chromium alloys were, cited. It was later determined that the best alloy of the series was the 80/20 nickel-chromium alloy. Handbook of Non-Ferrous Metallurgy, McGraw- Hill, 1926, volume '2, page 1315, referred'to the nickel-chromium and nickel-chromium-iron alloys for heating elements and stated that the commercial alloys contain 5% to 20% chromium,

5% to 40% iron and the balance nickel. The

Dempster United States Patent No. 901,428 of 1908 had disclosed the use of nickel-chromiumiron alloys for electric resistance elements. The Dempster alloys contained more than 10% and less than 50% iron, for example, 20% iron. A

. loy containing 80% nickel and 20% chromium The present invention may be applied with and the nickel-chromium-iron alloy containing 60% nickel, 25% iron and 12 to 15% chromium. Hunter stated that it was commercially practicable to make binary nickel-chromium alloys containing up to 30% chromium. Hunter stated that the alloys may contain carbon, manganese,

silicon, aluminum, molybdenum, copper, etc., in'

small amounts, for example, 0.07% or 0.1% up to over 2%, and in some instances, for example, molybdenum, as high as 10%. Briefly stated, the

nickel-containing alloys adapted for use as electrical heating elements usually contain about 10% to about 30% chromium or more and the balance nickel or nickel and iron with or without some cobalt, the nickel content of the alloys generally exceeding about 50% nickel, i. e., the balance is metal of the iron group of which at least 50% of the alloy is preferably nickel. From their Liddells nature, these alloys give rise'to substantial difficulty during the wire producing processes on which the life of the wire may depend. Accordingly, the invention includes electrical resistance elements made from such alloys embracing small quantities of one or more alkaline earth metals and one or more of the group V elements, i. e., phosphorus, arsenic, antimony, etc.

Thepresent application is a division of my copending 'patent application Serial No. 104,179, filed October 6, 1936, which, subsequent to the filing of this application, matured into U. 5. Patent No. 2,159,048.

While the present invention has been described in connection with certain preferred embodiments, it is to be understood thatvariations. and modifications may be made by those skilled in the art. Such variations and modifications are considered to be within the spirit and scope of the appended claims. i

It is to be understood that the term deoxidation, as used herein, includes such preliminary treatment as deoxidizing, desulfurizing, etc.

I claim:

1. As an article of manufacture, an electrical resistance element made of an improved workable nickel alloy comprising about to about 30% chromium, about 0.01% to about 0.2% calcium, about 0.01% to about 0.25% or at least one senic andantimony, and the balance substantially all nickel.

3. As an article of manufacture, an electrical resistance element made of an improved workbility comprising about 10% to about 30% chromium, about 5% to about iron, about 0.01% to about 0.2%, calcium, about 0.01% to about 0.25% of at least one of theelements of the group consisting of phosphorus, arsenic and antimony, and the balance substantially all nickel.

5. A nickel-base alloy adapted for use-as an electrical heating element comprising about 10% to about 30% chromium, about 0.01% to about 0.2% alkaline earth metal, and at least one of the elements of the group consisting of phosphorus, arsenic and antimony within the range of about 0.01% to about 0.06%, about 0.01% to about 0.2%, and about 0.01% to about 0.25%, respectively, and characterized by high workability compared to a similar alloy free from phosphorus, arsenic or antimony.

6. A nickel-base alloy containing from about 0.01% to about 0.2% of alkaline earth metal, about 0.01% to about 0.25% of at least one element from the group consisting of phosphorus, arsenic and antimony, and characterized by high workability compared to a similar alloy free from phosphorus, arsenic or antimony.

' LEONARD BESSEIVIER. PFEIL,