US3205055A - Metallic elements adapted to come in contact with melted glass - Google Patents

Description

Sept. 7, 1965 B. LAURENT ETAL 3,205,055

METALLIC ELEMENTS ADAPTED .TO COME IN CONTACT WITH MELTED GLASS Filed June 20, 1961 [055 OF MAE/6H7 IA/ PEEC'EA/ r465 u 70 1211 2'10 z'so 3'50 77/145 //1/ H0 mes INVENTORS ATTORNEY United States Patent 3,205 055 WTALLIC ELEMENTS ADAPTED TO COME IN CONTACT WITH MELTED GlL'ASS Bernard Laurent, Paris, and Igor Fezenko, Aulnay-sous- Bois, France, assignors to 'Compagnie de Saint-Gobain,

Neuilly-sur-Seine, Seine, France, a corporation of France Filed June 20, 1961, Ser. No. 118,353 Claims priority, application France, June 24, 1960, 831,045 1 'Claim. (Cl. 65-1) The present invention refers to metallic pieces or elements provided with orifices of generally small diameter, through which flows melted glass at high temperature, these pieces or elements themselves being brought to a high temperature.

It is the object of the invention to provide metallic pieces or elements which present a particularly high resistance to corrosion produced by the flow of glass, particularly in the passage of the molten glass through orifices disposed in these metallic elements.

The invention relates particularly to rotating hollow bodies or centrifuges, each provided with a peripheral band or wall having a plurality of orifices therein, through which the melted glass is projected in the form of filaments, which are then drawn out into fibers.

In accordance with the invention, these pieces or elements are formed of alloys containing the following principal constituents: chromium, cobalt (a part of which may be replaced by nickel), tungsten, a not insignificant proportion of carbon, and a very small quantity of iron. The proportions of these ditferent constituents may be comprised between the following limits: chromium 12% to 35%; cobalt 45% to 70%, capable of being replaced by nickel up to tungsten 3% to 15%; carbon 0.5% to 1.5%; and iron less than 1% The small amount of iron may be replaced, at least in part, by traces of niobium and tantalum in quantities of about 0.05% or 0.06% of the alloy.

The alloys in accordance with the invention may also contain traces of titanium, molybdenum and aluminum.

It has been determined that the pieces and elements thus constituted, presented, besides good mechanical resistance, an excellent resistance to the corrosion occasioned by the flow of the molten glass.

Particularly, advantageous results were obtained with alloys of the following approximate composition by weight:

' Chromium to Tungsten 4% to 7%. Carbon 1% to 1.2%. Iron Less than 1%.

These alloys may also comprise small quantities of stabilizers particularly in the form of silicon and manganese. The proportion of these stabilizers may be used advantageously in the amount of 1% to 2%.

In the accompanying drawing,

FIG. 1 shows comparative curves illustrating resistance to corrosion afforded by different metallic alloys against the effect of molten lass; and

FIG. 2 shows a rotary centrifuge for spinning fibers from molten glass composed in part, or in its entirety, from alloys in accordance with the invention.

The curves shown in FIG. 1 illustrate the comparative results .of losses in weight, in percentages, of two elements 10 (FIG. 2) of identical shape and size. Curves 1 and 2 portray the results when the centrifuges are made of alloys of the above type, in accordance with the invention, as set forth below, while curve 3 illustrates the loss in weight when the centrifuge is ofidentical size but when it is fabricated from a commonly used alloy, as tabulated below. The drawing shows, on the abscissas, the length of time during which the tested pieces were subjected to the action of the flow of melted glass and, on the ordinates, the percentage losses in weight.

These tests were made at 1030 C. corresponding to a mean viscosity of the glass of 1000 poises, this glass having the following composition:

Percent SiO 57.85 S0 0.30 F6203 A1 0 1 4.10 CaO 8.80 MgO 4 Na O 12.25 K 0 .-'50 B203 BaO 1.70 F 2.60 ZrO 3.95

Curves 1 and 2 portray, respectively, the behavior of the following alloys 1 and 2 composed of the following ingredients in the respective approximate quantities noted below:

' Percent Chromium 26.3 Cobalt 2 65.6 Tungsten 5.25 Silicon 1.6 Carbon 1.20 Niobium and Tantalum Less than 0.05

Chromium 31.40

Cobalt 54 Tungsten 12.5 Silicon .9 Carbon 1.07 Molybdenum O. 1 3 Aluminum 0.21 Titanium Traces Niobium and Tantalum 0.06

Curve 3 illustrates the effects on an alloy 3 having the following composition by weight:

Percent Chromium 24.84 Nickel 20.33 Silicon 2.04 Manganese 0.26 Carbon 0.38 Iron (difference) 52.1 5

It will be noted that the corrosion efiects by the action of the molten glass is very much weaker in the case of metal pieces according to the invention than in the case of pieces made according to the usual technique. In particular, it is evident that after about 350 hours contact with the glass, the pieces made with alloy -3 lose about 20% of their weight, while the same parts made according to the invention wit- h alloys 1 and 2 above, lose only about 1.2% and 3.6% in weight, respectively, in the same period of time.

Spinnerettes in the form of nozzles or rotating centrifuge bodies 10 (FIG. 2), with a peripheral wall 11 provided with projection orifices 12, conforming to the instant invention, present the great advantage that the spinning or projection orifices retain a constant diameter over a long period of time. Hence, these elements produce filaments or fibers of glass of substantially constant diameter or thickness, without the necessity of frequently replacing the spinning parts or rotating bodies, as is required to be done with these parts at the present time.

It has been determined, in particular, that excellent resistance, to corrosion was obtained in the case of rotating bodies with peripheral walls fitted with projection orifices when utilizing glasses having a viscosity in general between 800 and 6000 poises and the temperature of which, as does that of the rotating bodies, ranges between 990 and 1150 C.

Alloys in accordance with the instant invention may be used in the fabrication of one of the layers in a composite metal structure seeking a high degree of resistance to the corrosive effects of molten glass, for example as disclosed in the application of Levecque et al., Serial No. 718,654, filed March 3, 1958, now US. Patent No. 3,031,717.

We claim:

In a glass spinning apparatus, the improvement comprising a hollow rotatable metallic body having a pcripheral wall with a plurality of orifices of small diameter through which are projected by centrifugal force thin filaments of molten glass, said body being composed of a metallic alloy having good mechanical resistance and high corrosion resistance and consisting essentially of the following ingredients in the respective proportions by Weight: chromium ranging from approximately 25% to 35%; a

combined cobalt and nickel content ranging from approximately to with the nickel content in a minor amount ranging up to 15%; tungsten from approximately 4% to 7%; carbon 1% to 1.2%; and iron less than 1%.

References Cited by the Examiner UNITED STATES PATENTS 1,489,116 4/24 Chevenard 171 1,543,921 6/25 Huff 7517l 1,698,934 1/29 Chesterfield 75171 2,101,970 12/37 \Vissler 7517l 2,246,078 6/41 Rohn et a1. 75171 2,381,459 8/45 Merrick 75171 2,780,542 2/57 Cormack 75171 2,855,295 10/58 Hansel 75-171 2,900,252 8/59 Woodward 65-1 2,931,062 4/60 Leaman 6515 2,996,379 8/61 Faulkner 75171 3,026,199 3/62 Thielemann 75--171 3,085,005 4/63 Michael et a1, 75-171 3,118,763 1/64 Thielemann 75171 FOREIGN PATENTS 108,164 7/ 17 Great Britain.

153,626 1/51 Australia.

205,437 12/56 Australia. 1,169,211 12/58 France.

DONALL H. SYLVESTER, Primary Examiner.

MICHAEL V. BRINDISI, DAVID L. RECK,

Examiners.

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