US2023957A

US2023957A - Method of casting phosphorized copper

Info

Publication number: US2023957A
Application number: US709303A
Authority: US
Inventors: Hewgill Russell
Original assignee: American Metal Co Ltd
Current assignee: American Metal Co Ltd
Priority date: 1934-02-01
Filing date: 1934-02-01
Publication date: 1935-12-10
Anticipated expiration: 1952-12-10

Description

Dec. 10, 1935. R. HEWGILL METHOD OF CASTING PHOSPHORIZED COPPER Filed Feb. 1, 1934 INVENTOR ATTORNEYS.

Patented 7 Dec. 10, 1935 I PATE T OFFICE METHOD OF CASTING PHOSPHOBIZED COPPER Russell Hewgill, Sudbury, Ontario, Canada, assignor to The American Metal Company, Limiegi New York, N. Y., a corporation of New 7 application February 1, 1934, Serial No. 709,303

This invention relates to the casting of phosphori'red copper, and may be used for the casting of other deoxidized copper alloys. Phosphorized copper is a deoxidized copper containing a 5 residual amount of phosphorus as a deoxidizing component and a alyzes approximately .02 per cent. phosphorus. I

The casting of phpsphorized copper involves considerable difliculty. It must be cast under very different conditions from those required in the casting of electrolytic copper or tough pitch fire refined copper. For these the molds must be heated preferably inthe neighborhood of 100 C. and the mold surfaces or casting cavity dressed 15 with awash of bone ash. For phosphorized copper, on the contrary, the mold must be kept cold-a.

. and the mold dressing is an 011 mixture.

.Ih'the' production of phosphorized copper the addition of phosphorus in the form of a rich phosphoriz'ed copper alloy to the molten copper bath imparts certain characteristics ,to the bath' which make vit difficult to obtain a satisfactory casting unless special precautions are taken..

Phosphor copper when coming into contact with air appears to form a certain amount of a compound very rich in phosphorus,.assaying as high 88-33% P, which compound when it comes in contact with the cold mold surface almost immediately sets and causes a hole or depression in 30. the finished casting, making it unsuitable for ordinary commercial uses. In order to avoid this result, a stream women-excluding gas,

v such as a gas containing carbon monoxide. produced in a charcoal or other fuel gas producer,

as is directed into the mold during the casting procedure, however, does not in itself produce a satisfactory casting although somewhat better than when air is not excluded, as it ap- 40 pears that the mold dressing i s not completely.

decomposed by the heat of the molten copper, and there remains on the mold walls a solid decomposition product of the oil which also pre- .ventsthe production of a satisfactory surface on Q '45 the finished casting.

I have discovered that by adding water to the mold the difficulties heretofore encountered are avoided, resulting in the production of copper cakes, billets or other castings, having a satis- 50 factory surface condition, with no perceptible increase in the internal porosity of the casting.

Water may be variously added to provide a awater' film coating on the walls of the casting cavity by first introducing a pool of water into ($6 the mold which may be drained therefrom prior to pouring the molten metal, or by spraying water into the-mold during the pouring, or by introducing a stream of water together with the pour ing, or by introducing atomized water, or a spray or fog or other moist condition carriedv into the 5 mold with the producer gas. The use of water is advantageous either with or without the use of such gas in casting.

The preferable mode of practicing the invention is as follows: The casting may be accoml0 plished in any known or suitable mold, prefer ably in an upright mold'of copper cooled'by circuiation of water through a surrounding water jacket. After the mold dressing is applied, water is sprayed into the mold over the sides of the 15 cavity and at the bottom thereof; then, during the pouring, .as soon as the metal within the mold has formed a substantial pool (to a depth of two or three inches, for example) water is added to the mold in a small stream or spray in 20 sufficient quantity so that a fairly large poolzof water is kept on the surface of the molten metal, preferably both in front of and behind the stream of metal entering .the mold. When sufllcient water has been thus added the water stream may 25 be shut down, or may be diminished so that the additional water introduced is only suilicient to just compensate for'the loss in evaporation.

The. use of water in this manner appears to serve two purposes; the water sprayed on the sides of the mold cavity is transformed into steam when the hot metal makes contact'with it, and the bubbles of steam thus formed appear to prevent the high phosphor compound or slag from coming into contact with the sides of the cold mold and congealing thereon. The force ofthe steam thus ,generated appears to be suillcient to throw this compound, together with any carbon formed from the decomposition of the oil dressing, towards the center of the mold, where it is 40 caught in the larger pool of water and kept floating or suspended therein until the mold is filled with the copper, and in this manner it is prevented from coming into contact with the sides of the mold'and congealing thereon in the manner which heretofore 'gave trouble in creating a cavity in the surface of the casting.

Satisfactory results have been obtained with both vertical cake molds and vertical round billet molds. It is preferable but not essential to in-- 'troduce producer gas into the mold prior to and during 'the pouring.- This use of gas is advantageous, but is not necessary in the. casting of billets; but in the casting of cakes it has greater advantage, and in some cases appears to be a cavity as indicated in Figs. 1 A metal isto be cast without 'spout and ladle may be hooded overin the well mold cavity is closed necessary procedure to the attainment of successful castings.

It is impossible to state with exactness the quantity 01' water to be added during the east ing. In casting billets the interior of the mold after dressing should be sprayed withwater until its surface is totally covered with fine drops. For such casting this alone has proved a suflicient addition of water,- althoughit is desirable also to introduce a fine stream into the mold during the pouring period. The water may be introduced in the form of steam, although this has not proved as satisfactory as a spray of water.

"In the casting of copper cakes, experience has indicated that it is important to spray the mold with water before any metal is added and there-' after to continue introducing water in a stream or spray in suflicient quantity to maintain always a small pool on the molten copper, which should be bothin front of and behind the metal stream. The pool of water which is maintained on the surface of the molten metal need only be of sufficient depth to float and prevent the slag or dross containing the phosphorus from coming in contact with the molten metal or the sides 01' the cold metal.

While it is practicable to introduce the water in the form of steam or water vapor or atomized water intothe stream of producer gas which is introduced into the mold, this method does not have .any advantage over .the introduction of water directly through a small pipe, and .the latter is believed to afiord greater facility for the control of the introduction of water.

No special apparatus is required, but as an illustration of suitable means reference may be made to the accompanying drawing, wherein- Figs. 1 and 2 show respectively in vertical section and in partial horizontal section a vertical mold for castingrectangular copper cakes; and

Figs. 3 and 4 are similar views showing a vertical billet or ingot mold for casting cylindrical billets "or analogous shapes.

Fig. 5 is a sectional elevation of pipes for introducing water and gas together into the furnace.

this being provided by forming a closely related B communicating at bottom with a passage extending around within the mold wall and receiving cooling water from an inlet D; and united at the top in a passage E extending around within the upper wall of the mold, whence the water issues through an outletF'. The bottom of the by a-door G, which may be hinged as shown in Fig. 3 and .held up by a bail H or other support wedged beneath it, by removing which the door may be dropped open and the casting dumped out. Such molds are'known and regularly used for makinslcopper castings.

The phosphorized. copper is taken from the furnace or other container by a spout H, whence it pours into a ladle J of usual construction, which may rest on the top of the from which the metal pours and '3. When the access 01' air, the

known manner to form a chamber into which suitable oxygen-excluding gas'is introduced.

All these features form the customary casting means and require no alteration in the practice of the present invention. j For casting under gas protection, it is common In the drawgig, A designates the mold, which is water-jackete series ofvertical ducts or bores mold as shown, and' over intothe mold' to cover over the top of the mold with a'p'late K through an opening in which gas is introduced through a pipe L, as shown in Figs. 1 and 2.

For the introduction of water in the form of jets or spray or steam, any suitable. pipe may be employed, an exampleof which is shown at M. This may be an iron pipe coupled at its top to a hose N. This pipe may be introduced through the free potu'ing space to the right of plate K, as shown in Figs. 1 and through the plate K, as shown in Fig. 3, in case no separate gas pipe L is used. The pipe M is freely movable up and down and may be grasped by tongs or otherwise manipulated bythe oper- 2; or it may be introduced 6 ator, who will initially lower it and turn on su1- 5 without it. Any suitable valve P is provided within convenient reach of the operator by which he can control the flow of water.

If the water is to be introduced with the gas it is desirable to spray or atomize the water into the stream of gas, which may as shown in Fig. 5 where the water is introduced under pressure through a pipe Q under control of a valve, into an atomizing, commingling nozzle R, to which gas is conducted through a pipe S, and the flow of commingled gas and spray or mixture is conducted thence through the pipe L to the mold.

As one example, it may be stated that experience has shown-that suitable results are secured be accomplished 2.4 litres (3 H. oz. to 2.6 qts.) is used with a mold wherein the pouring occupies a very short period; say around 15 .seconds, and more with larger molds where the pouring takes longer, as for ex: ample, with a 600 lb. over 2 minutes; but success may be attained when lessor even more water is us v I It will be obvious to those skilled in the copper casting art that the mode of introducing the wateror mixture into the mold may be greatly varied without departing from the present invention;

While the described process has proven highly eflicacious and valuable with, phosphorized cop:

per, it appears to be also available for improving the casting of other copper alloys having similar casting, which may take 40 to be due partly to the me- -a black slaggy material .and is so far eliminated 0 by the solvent action of the water as to avoidits occlusion in the casting.. The invention is accordingly applicable to other copper alloys,

wherein a water soluble oxide or compound is produced during the casting operation. It may 05 V perhaps also be'available in the case 01 those alloys wherein the compound formed during castiifg is not water soluble, as in the case of copper containing silicon; but its applicability to the casting of such other alloys has not yet been den termined.

-What I claim is:

1. The process of casting deoxidized containing a small prising coating the copper amount of deoxidizer. comwallsof the casting cavity.

. comprising introducing water into the mold so as to provide a water film coating on the walls of the casting cavity preliminary to the pouring of the molten metal and providing a pool of water in the mold above'the molten metal of merely sufiicient depth to float the dross, by introducing water into the mold together with the molten metal after a pool of metal has formed in the mold.

4. The process of casting deoxidized copper according to claim 2 wherein the water is introduced into the mold in subdivided form.

5. The process of casting deoxidized copper according to claim 2 wherein the water is introduced into the mold in the form of steam.

6. The process of casting deoxidized copper according to claim 2 wherein the water is introduced into the mold together with an oxygen-excluding gas. a

7. The process of casting deoxidized copper according to claim 2 wherein the water is introduced into the mold together with gas containing carbon monoxide.

8. The process of casting deoxidized copper alloys containing a small amount of deoxidizer, comprising dressing the walls of the casting cavity with an oil mixture, providing a water film coating upon said dressed walls preliminary to the pouring oi the molten metal, and introducing water into the mold during the pouring oi the molten metal.

9. The process of casting deoxidized copper alloys consisting in dressing the walls of the casting cavity with an oil mixture, providing a water 5 film coating upon said dressed walls preliminary to the pouring of the molten metal, and introducing water into the mold during the pouring of the molten metal to provide a pool of water in the mold above the pool of molten metal;

10. The process of casting phosphorized copper comprising coating the walls of the casting cavity with a film of water preliminary to pouring the molten metal, and introducing water during the pouring of the molten metal to provide a pool of water in the mold above the pool of molten metal of merely sufilcient depth to float the dross, and adding said water in amounts to compensate for evaporation of water from the mold to maintain the pool of water above the molten metal in the mold.

11. The process of casting deoxidized copper, comprising pouring molten metal into a mold, and after ,a pool of metal has been formed therein, introducing water into the mold during the pouring of the molten metal in merely sufiicient quantity to provide and maintain a pool of water above the surface of the molten metal to fioat the dross and to compensate for evaporation of water from the pool, said pool of water having no practical cooling effect upon the molten metal.

12. The process of casting deoxidized copper, comprising pouring molten metal into a mold, and after a pool of metal has been formed therein, introducing water in subdivided forminto the mold during the pouring of the molten metal in merely sufilcient quantity to provide and maintain a pool of water above the surface or the molten metal.

RUSSELL HEWGILL.

CERTIFICATE oF' CORRECTION.

Patent no. 2,023,957. I Q December 10, 19:55.

RUSSELL HEWGILII.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, lihe 26, for "metal" read mold; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealedthis 28th day of January, A. D. 1936.

Leslie-Frazer (Seal) Acting Commissioner of PatentB.