US885668A - Method of uniting iron or steel with each other and with other metals. - Google Patents

Description

UNIT D STATES PATENT OFFICE.

EVAN IiLEWELYN DAVIES AND WILLIAMGJCLARKj, or wEssELs NEK, NATAL.

METHOD OF UNITIN'G IRON OR; STEEL WITH EACH OTHER AND WITH OTHER METALS.

Application filed August 7, 1905' Serial No. 273,212.

Specification of Letters Batent.

Patented April 21, 1908.

with Other Metals, of which the following ishis invention'which is an improvement on the method described in the specifications to British atent No. 10763 of 1899,rela'tes 5 to a method of welding iron or steel with each other or with other metals such as copper or its alloys, silver or gold or their alloys,. and

to the composition of fluxes to be employed in connection with such processes, the object of the invention being to obtain a more com,- plete adhesion of the metals to one another j than has so far been accomplished.

The improved method will be with reference to the coating or welding of steel sheets with a film or coating of cop er of any desired thickness, but it is to be un er: stood that it may also be applied to the coating of any kind of iron p ate, tube or wire with other metals than copper or with cop' per or other alloys,- and also to the uniting of iron or steel plates .or barawith each otheror with plates or bars of copper or other metal or alloy.-- I The iron or steel plate to be coated is heated to a temperature, which should be considerably above that of the melting point of the coating metal, and when possible approximately that of theboilin'g point of t e coating metal, such a temperature under usual conditions entailing the. conversion of any iron oxids on its surface into the black oxid, and is laced in a suitable mold in a furnace in w ich itis maintained at-about the same temperature. In this furnace, in

the melted condition sup lies of a flux, the

composition of which wi be hereinafter de-v scribed, and of copper or other coating metal.

flux, preferably covered with'a layer-of cardescribed suitably formed hearths, there are kept in he mold containing the iron plate is then partly filled with liquid,

bon in suitable form, such as ground charcoal, the iron oxid on the plate combining with fluxand leaving a'clean iron surface.

The separation of the iron oxid and its chemical combination With the flux may be. facilitated by .the use of scrapers or rakes passed over the surface of the iron plate and agitating the flux. The melted copper is then admitted to the mold and being heavier 5 than the" flux takes its placeyso that the liquid copper becomes covered with the-layer of flux thus reventing to some extent the oxidation of its surface when exposed to an oxidizing atmosphere. -The. me ted copper 7 is thus brought into intimate contact with a clean iron surface at a welding heat, and an intimate union of the copper and iron is obtained, thisbeing'facilitated and a homogeneous distribution effected by the useof scrapers or rakes as above described, or by' other suitable means of agitating the layer of melted copper. The mold containing'the coated plate u on its withdrawal from the furnace may e covered with a sheet of so metal to revent access of the air as far as possible uring cooling. 1 Since'it is practically impossible in carrying out the process in a furnace with an oxidizing atmosphere to prevent the oxidation 5 of the copper to some extent, it is important that the copper used should be what is known asslightly over oled, or in that condition of brittleness whic requires oxidation to bring it back to the tough condition. Should the heating furnace used not have an oxidizing atmosphere it may be unnecessary to use over poled'copper;

When it is deslred to coat both surfaces of the late, it is practically necessary to use two urnaces, inone of which copper is kept molten in a bath having a magnesite or other basic lining, while the other furnace is used to raise the plate "to the temperature fofthe molten copper or such a higher tem erature as may be necessary to allow fort e una-v voidable fall of temperature in bringing the late and the molten copper into contact. his latter furnace also contains on its hearth a bath of the particular flux used in the procass in a molten condition,- and the "late on being taken from the furnace is st immersed in this bath whereby its surface is cleaned and covered with a film or molten fiux, and is then placed in a suitable mold of 1 0 ma esite" clay or ordinary foundry loam, whichhas been previously heated to as high a temperature as it standby a gas flame" or other suitable means. The molten copper is then run into the mold and, displacing the film of flux comes into intimate contact with the clean'surface of the iron at a welding heat 'and rigidly adheres thereto.

In a modified method of carrying out the 'process and one which obviates the difficulty experienced by the fact thatthe liquid cop- 1 its edge 'w per more or less readilypermeates the lining of the copper bath hearth, more particularly if ordinary silica bricks are used for this purpose, the plate to be coated is formed with ich may previously have been reduced in thickness, u wardly turned, preferably through an ang e of 90 at least, and

- liquid or solid flux is poured or sprinkled over the surface to be coated and the coating metal is added in the molten condition or in small ieces distributed over the surface, no mold eing required. Suflicient flux ShOUld be added to cover completely the copper or other coating metal when melted and the copper used should be over poled if the furn'ace to be used has an oxidizing atmosphere:

The flux and copper are melted in heating the plate as rapidly as possible to an oxidizing temperature, which may be done in any' amount to 4 per cent. or thereby of the total quantity of flux, of sodium phosphate or bone ash, the phos horus serving to increase the fluidity o' the copper, and thus preventing pin holes. At the same time the proportions and even the constituents may vary, as for example by the omission of the sodium borate or the substitution for the carbonate and borate of soda of other carbonates and borates and the proportions given above are by no meansthe on y proportions which may give good results, such variations deending upon the character of the metals to lie welded and the composition of the lining of the flux bath if such is used. The silica and carbonate of soda by themselves form a, fusible silicate which has the property at the worklng temperature of dissolving the iron oxid and the sodium borate is added chiefly for the purpose of dissolving any copper oxid which may be formed, or in conjunction with carbon which is added to the flux elements, preferably in the form of ground charcoal, to reduce or to prevent the formation of such, thereby reducing waste of copper.

When wire or thin strip metal is to be coated this is heated to an oxidizing tem-' perature and then drawn through a vessel having a suitable neutral or basic brick lining containing the molten copper and divided into two parts by a depending partition which, however, does not extend to the bottom of the vessel, so that the wire or strip can be drawn through the molten metal under the partition. On the entering side for the wire or strip, the surface of the cop )er is covered with a flux, such as described a ove, which is in the liquid state, while on the emerging side of the vessel, the flux covering consists usually of sodium carbonate and sodium borate with the addition of powdered carbon, but the composition of this flux may vary in accordance with the constitution of the lining of the containing vessel, the only condition to befulfilled being that the surface of'the copper bath will be protected from oxidation. On passing out of the furnace the wire or strip may be cooled by passing through a stream of water and afterwards annealed or otherwise treated as may be desired.

When tubes are to be coated these may be treated in a similar vessel the tubes being caused to enter the vessel transversely and to revolve by running down an incline. Or two or more vessels may be used, the first of which contains molten flux in which the tube is first immersed, the second bath containing the molten coating metal and being situated at a lower level at the end of an incline down which the tube rolls from the flux bath, while thethird bath, if such is used, is at'a still lower level and contains molten flux of a similar nature to that in the first bath. The tube continues to roll through the molten metal in the second bath in which it is par-' tially immersed and becomes uniformly coated therewith, and fromwhich it passes or. is transferred to the third bath in which it is temporarily immersed for the removal of dirt from the metal surface.

The rolling of the tube is maintained by means of an inclined plane or otherwise after it leaves the bath until the coating metal has become solidified. When coating iron or steel withgold or silver or alloys thereof or ofcopper, the same fluxes are employed but the proportions may be somewhat varied to suitthe temperatures re uired for the various coating materials, tie essential condition being that the flux is in a fluid condition at the welding temperature.

If the plate or other article to be coated is rusted or itted it is advisable before treating it asiiereinbefore described to dissolve the rust by treating with suitable acid and to remove the inequalities if any by rolling or other suitable means so as to obtain a smooth surface.

When it is desired to weld iron or steel with themselves or each other as for. example to weld hard tool steel on a mild steel bar, the

parts to be welded are raised to the oxidizing temperature of iron and are then lungedv into a bath of flux maintained at t e' same temperature and containing silica and car bonate of lime in about e ual proportions. The'fiux dissolves any ox i on the surfaces to be welded, which by immersion in the flux are brought to -a white heat, thus enabling the welding to be effected on bringing the two steel bars together quickly on Withdrawal in the ordinary way.

We claim:

1. The herein described method of uniting iron or steel with each other or with copper gold or silver or their alloys which consists in heating the surface of the iron or steel considerably above the melting point of the metal with which it is to be united,-ren1oving the iron oxid by a-suitable flux andbringing' the uniting metal heated to a corresponding temperature into intimate centac't with the surface of the iron while the temperature is maintained, substantially as described.

2. The herein described method of uniting iron or steel with each other or with copper goldor silver of their alloys which consists in heating the surface of'the iron or steel considerably above the melting point of the metal with which it is to be united, immersing the iron or steel surface in a suitable flux to remove the oxid, and displacing the flux from the iron or steel surface by bringing the latter into intimate contact with the metal with which it is to be .united in a mold, the temperature of the mold and of the said metal having been previously-raised tov a temperature considerably above the melting point of said metal, substantially as described.

I 3. The hereindescribed method of uniting.

iron or steel-plates with copper, gold or silver or their alloys which consists-in 'heatin the iron or steel considerably above the me ting point of the metal with which it is to be united and in removing the iron oxid by a suitable flux and bringing the metal with whichit is to be united into intimate contact with-the iron by adding the said flux and metal, thelatter in small pieces to a mold formed by upturning the edges of the plate, while the 'tem' perature of the latter is maintained, substantially as described.

4. The herein dGSCI'll'X-Ml method of uniting iron or steel with eachother or with copper,

'ate'and 'a small quantity of sodium goldor silver or their alloys, which consists in heating the surface of the iron or steel approximately to the boiling point of the meta with which it is to be united, removing the iron "oxid by a flux containing approximately equal quantities of silica and an alkali carbonate and a small uantity of sodium phosphate, and heating t e metal with which the iron or steel is to be united to a corresponding temperature and bringing the metal into intimate contact with the surface'of such iron or steel while the temperature is maintained,

substantially .as described.

5. The herein described method of uniting iron or steel with each other or with copper,

gold or silver or their alloys, which consists in heating the surface of the iron or steel approximately to the boiling point of the metal with which it is to be united, removing the iron oxid by a flux containing approximately equal quantities of silica and sodium carliIon osphate, and'heating the metal with whic the lIOIl or steel is be united to a corresponding temperature and brin ing the metal into intimate contact with t e surface of-such iron or steel while the temperature is maintained, substantially as described.

6, The herein describedmethod ofuniting iron or 'steelwith each other or with copper,

gold, or silver or their alloys, which consists in heating the surface of the iron or steel approximately to the boiling point of the metal with which it is to be united, removing the ironoxid by a flux consisting of silica, sodium carbonate, and sodium borate in about equal proportions with the addition of a small quantity of sodium phosphate, and heating the metal with which the lI'OIl or steel is to be united to-a corresponding temperature and bringing the metal into intimate contactwith the surface of such iron or steel while the temperature is maintained, substantially as descr bed. i

In testimony whereof we have signed our names to this specification inthe presence of two subscribing Witnesses.

.E. LLEWELYN DAVIES. W. CLARK.

Witnesses: i

,C. 'L. HoPKms,

JosEPH WILLARD.