US900846A - Plated metallic body. - Google Patents

Description

GEORGE A. GOO DSON, 01* MINNEAPOLIS, MINNESOTA.

PLATED METALLIC BODY.

Specification of Letters Patent.

Patented Oct. l3, 1908.

Application filed March 28, 1906. Serial No. 308,445.

and I do hereby declare the following to be a full, clear, and exact description of'the invention, such as will enable others skilled in the I art to which it appertains to make and the same.

My invention relates to that class of metallic bodies which are protected against corrosion under the action of the elements, as, for example, those in the air or in water, by metallic plating; and has for its object to provide an improved product or article of manufacture of this general class. Hitherto, as is well known, it has been the common practice to galvanize or plate metallic bodies, such, for example, as iron and steel wire, or iron or steel sheets or plates, with zinc as the plating metal, or with an alloy composed of about one-third tin and two-thirds lead; and this plating has been done bysubmer ing the wire or other metallic body in the sai classes of molten plating metal at the proper temperature.

Zinc or an alloy of tin and lead, such as above stated (owing to the presence of the tin therein), have such great affinity for iron or steel that such plating metals can be made to adhere to wire or steel metallic bodies by said old process above indicated. Zinc is a hard and brittle metal; and, when used for plating purposes, is apt to crack and scale should the wire or other lated body be twisted, hammered, or ot erwise distorted; and to minimize this tendency to crack or scale, it has, in practice, been found necessary to apply only a very thin coating or plating of the zinc to the wire or other USB metallic body. In this effort to employ only a thin coating of zinc, the metallic body so plated is frequently left uncovered in laces,

body

which, of course, renders the plate much more liable to deterioration by corrosion under the action of the elements; and, moreover, such extremely thin plating soon deteriorates from corrosion.

The above stated alloy of tin and lead can be ap lied to the wire or othermetallic bod in a thicker coat, because such alloy is muc less brittle than zinc. .Tin, however, rapidly deteriorates from the corrosion incidental to the action thereon ofthe elements A. GooDsoN,

, of the in the air or water, and to which the wire or other body plated therewith is necessarily exposed in the service; and tin has thus been employed hitherto with the lead, simplly because of its known allinity for iron or stee or otherwise stated, the alloy could be made to adhere to, the plated body and lead could ,not.

It has long been known that lead would be the ideal plating metal, because of its pliability and its non-corrodibilit under the action of the elements to which such body must be exposed in actual service; but prior to the invention or discovery made by me, and disclosed in my U. S. Patent No. 789,690, of date May 9th, 1905, it had never been found commercially practicable to plate metallic bodies with lead. Lead has so little afiinity for other metallic bodies like iron and steel, that, under the old process, which was satisfactory for lating with zinc, or withthe above stated alloy of tin and lead, the lead could not be made to adhere 'to the plated body. Under my said rocess, disclosed in my said patent, I have ound that iron and steel bodies can be plated with pure lead, and that the union is so close as to fpermanently unite the two metals. By re erence to my above identified patent, it will be seen that I accomplish this result by subjecting the wire or other metallic body to be lated to a bath of molten plating metal, w ich has been subjected to an electric current of the roper strength, While the said plating meta was in mo ten condition. In my actual practice, I have ordinarily employed a current of from 1500 to 2000 am eres for a cross section of one inch. The ody to be plated is, of course, cleaned by pickling the same in the usual way before it is submerged in the molten bath of the plating meta I have plated considerable quantities of iron and steel wire with pure lead as the plating metal, under my said process above noted, and have also plated considerable quantities of iron and steel sheet metal with pure lead, under my said process, and I have found that theumon between the particles plated body and the lead is so close that the lead will not scale, crack, or break even when the wire or other plated bod is twisted, hammered, or drawn. If the ating metal, has been properly treated with the electric current, it appears to be a matter of indifference whether the current is on or off its ductility and non-corrodibility is eon-v cerned; and the only objection there is to the use of pure lead is that it is a little too soft, and will wear away under some classes of service where it is liable to abrasion from any cause. By the addition of a small percentage of antimony, to wit, about 13 percent. to the 87 percent. of lead, I get an a lo? having all the required properties of pliabi ity, and non-cor'rodihilit necessary for good commercial service, whi e, at the same time, the requisite hardness is present to revent the ready wearing awa from a rasion. The presence of this smal quantity of antimo'ny does not appear to in any wise diminish or impair t e closeness of the union which takes place between the particles of the plating metal and the body tobe plated,

when the plating is done under my process above pointed out. So far in my ractice, I have only tried out antimony as t e hardening metal to use in connection with lead, but it is probable that some other hardening metals, such as arsenic, might possibly be used, and hence I do not limit myself, in a broad point of view, solely to use of antimony as the hardening element.

Having thus described my invention, what I claim and desire to secure by Letters Pat- 'ent, is

GEORGE A. GOODSON.

Witnesses:

JAS. F. WILLIAMSON, EDWIN S. CLARKSON.