US2032322A - Flux-coated electrode - Google Patents

Description

Feb. 25, 1936. JUDY 2,032,322

FLUX COATED ELECTRODE Filed April 10, 1934 lzmenz' (e,

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PRU L Patented Feb. 25, 1936 UNITED STATES FLUX-COATED ELECTRODE Paul R. Judy, Muncie, Ind., assignor .to Indiana Steel & Wire Company, Muncie, Ind., a corporation of Indiana Application April 10,1934, Serial No. "#9346 2 Claims. (01. 219-s) It is the object of my invention to, produce a flux-coated electrode or weld-rod in which the flux-coating not only facilitates the welding operation and protects the welding during its mak- 5 ing and'forms only an easily removable slag, but also one in which such flux coating is made of readily obtainable and inexpensive materials.

In arc welding, as is well known, it is desirable to protect the molten metal both while it is being transferred from the electrode to the work and while the deposited metal is solidifying and C001? ing; and to provide in the coating the necessary ingredients to accomplish this purpose To protect during the solidifying and cooling, it is desirable to provide on the molten metal a thin.

film of protective material, and to have this film substantially continuous and unbroken until the metal has solidified and'cooled; but to have the film of such character that when the whole is cold such film is quite friable and easily removable. By maintaining the film unbroken while the weld-metal is liquid, unevenness of the surface and of the boundary of the weld is in large measure avoided. While the same materials 5 which protect the deposited metal also serve to some extent to protect the metal as it is being deposited from the electrode, this latter protection may be more effectively obtained by providing a non-oxidizing gaseous envelope for the metal as it is being deposited; and this gaseous envelope can be obtained by providing in' the weld-rod coating an organic material, such as 45 tain an unbroken protective film while the de-.

posited metal is liquid anduntil it has solidified and cooled. Although either the ilmenite alone or (usually) the aluminum-bearing silicate alone is not friable, and tends in general to yield a slag 50 which is hard to remove, even withsodium silicate present, the co-presence of the ilmenite and the aluminum-bearing alkali-metal or alkalineearth silicate, such as feldspar or mica, makes a resultant 'slag which is quite friable and easily '55 removable.

In addition to these three fundamental ingredients, I may and desirably do provide other ingredie'nts in the coating. The chief among these is an organic material, such as wood ur.

I Others may be ferro-manganese and gum afrabic; 5

but they are relatively secondary.

The accompanying drawing shows a coated welding electrode or weld-rod embodying my' invention: Fig. 1 is an elevation of such a coated welding electrode, partly broken away to show 10 a longitudinal section; and Fig. 2 is a cross-section of such coated welding electrode, on the line 2-2 of Fig. 1.

In such drawing, the metallic wire or rod Ill, usually a ferrous wire or rod of desired composi- 15 tion, is covered for all or the greater part of its length by a coating II; and this coating is made of the mixture of ilmenite and an aluminumbearing alkali-metal or alkaline-earth silicate,

with a binder silicate (such as sodium silicate), 20 desirably with wood flour, ferro-manganese, and gum arabic also present, asdescribed above.

The ilmenite, which is an iron titanate is suitably reduced to a powder, for intimate mixing with the other ingredients used. a 25 The aluminum-bearing silicate is also reduced to'a powder, as by grinding, for intimate mixture with the other ingredients. It is most conveniently either feldspar or mica; but other aluminum-bearing alkali-metal or alkaline-earth silicates may be used, such as feldspathoids, zeolites, or epidotes. Various feldspars may be used, such as orthoclase, 'albite, oligoclase and labradorite; and various micas, such as biotite, muscovite, lepidolite, margarite, phlogopite, etc.

The binder silicate is desirably either sodium silicate or potassium silicate; desirably in' the form of water glass if sodium silicate is used, or of the analogous substance if potassium silicate is used.

These three ingredients may vary widely in their relative proportions. The ilmenite and the aluminum-bearing silicate may each vary from 10% to of the whole formed by these three desirably added in the coating. It has a multiple has several functions. Among these are that it helps in the binding action, and also helps in furnishing the carbonaceous gases. It usually is present in relatively small amount, such as 2% to 15% of the total weight of ilmenite and the silicates.

I give below an example of a coating mixture which I have found very effective, and which embodies all of the ingredients discussed above, although not all of them are necessary:

Percent Ilmenite 10 to 40 Aluminum-bearing alkali-metal or alkaline-earth silicate (such as feldspar or mica) 10 to 40 Sodium silicate (dry basis) 20 to 60 Wood flour 10 to Farm-manganese 5 to 15 Gum arabic 1120 5 In making the coating mixture, the ingredients are suitably mixed in the desired proportions, and applied to the electrode core in any suitable manner, as by being extruded thereon. The rod which has thus been coated is. suitably dried,

and is used in the usual manner of welding elecf trodes. It can be effectively used in all positions,

not only in the so-called down-handwelding, in which the work is below the electrode, but also for welding on vertical surfaces and in overhead welding. Also, the electrode is found not only to work with reverse polarity, or when it is connected to the positive side of the circuit, but also to work quite .well on fstraight polarity", or when it is connected to the negative side of the circuit-a versatility of operation which is unusual.

I claim as my invention:---

1. A weld-rod having a coating containing 11- menite, mica, and a binder silicate, with each of the first two forming from 10% to 40% of the total of the three.

2. A weld-rod having a coating containing 11- menite, mica, and a binder silicate, with each of the first two forming substantially one-fourth of the total of the three.

PAUL R. JUDY.

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