US1699665A - Brass composition and process of producing the same - Google Patents

Description

Patented Jan. 22, 1929.

UNITED STATES o'r'ro runxnn, or STOLBERG,1GEBHANY.

BRASS comrosrrron Ann :enocnss' or raonucme ran same.

Ho Drawing. Application flled July 23, 1925, Serial No, 45,467, and in Germany May 8, 1924.

-The ordinary brass of commerce maybe.

divided into two principal classes. One

class comprises brass having a copper con-' tent of less than 60%. As is well known, brass of this class is workable onlyin hot condition, because when cold it becomes hard and brittle andtherefore is adapted only for cutting or filing. On the other hand, the other main class, namely brass containing more than 60% of copper, is soft and ductile in the cold state and is therefore suitable for drawing and stamping work. When hot, however, it is easily fractured and consequently Is not workable.

The object of the present invention is to produce a brass of the second group which is well suited for all working methods in both hot and cold conditions.

I have observedthat in brass containing more than 60% of copper the characteristic of liability to fracture, occurs to a very high degree when such brass has been produced by melting down strongly oxidized metal. From this observation'I have deducedthat the oxygen in some way becomes incorpo- 7 method of releasing'the oxygen may be employed, provided the reduction of oxygen is sufficient so that the alloy will not be heated 40 to such a temperature as to produce in it the liability tofract-ure as above stated. I have found thatvery finely pulverized carbon, for instance in the form of pine soot, is suitable for the purposes of the present invention, since it can be added to the molten alloy in any desired quantity without forming injurious combinations such as are produced by other known deoxidizingagents, such for instance as manganese, alumina, silica or phosphor, all of which when used to excess have an injurious effect on the quality of the brass. Pine soot is very favorable for producing the desired deoxidizing efiect, as it forms on the molten metal a very loose layer rated in the alloyand impairs its capability oxygen to render the alloy malleable on which forms an effective insulation against heat and oxygen while permitting the alloy to be brought to a reduction temperature which is favorable for producing the desired deoxidizing effect and at the same time exeludes the'oxygen of the air.

The following is given as an example of the process: r

To produce a brass containing 67% copper and 33% zinc, the copper and zincare charged into a smelting furnace together with any desired quantity of pine soot. As soon as the metals aremelted the charge is stirred so as to thoroughly mix the metals, during which time further quantities of pine soot may be added to the charge. The alloy will in this manner be deoxidized to such an extentthat it is readily workable while hot without liability to fracture.

It is to be understood that the foregoing is given merely as an example, but that other suitable meansmay employed for releasing the oxygen without departing from the spirit and scope of the invention-since the special-manner of releasing the oxygen is unimportant so far as the present invention is concerned. I

p am' aware that theabove mentioned content of 60% of copper above which a brass alloy is only workable in the cold and below which it is workable only when hot, does not give a strict line of demarkation, and therefore I have limited the appended claims to a brass alloy, and to its manufacture, which consist substantially of copper and zinc only, the lower limit of the copper content being Having thus described'my invention, what Iclaim is:

1. The process of manufacturing brass which consists in melting together the brass forming metals comprising more than 63% in weight of copper with less than 37% in weight of zinc in the presence of soot and stirring the mixture when in molten condition so as to efi'ect thorough deoxidization.

2. As an article of manufacture brass comprising more than 63% by weight of copper when manufactured with the addition of pine soot in the melting process and malleable in both cold and hot condition.

In testimony whereof I have signed my name to this specification.

OTTO JUN'KER.