US992951A - Process for the manufacture of ductile electrolytic iron. - Google Patents

Description

' Io Drawing. Application filed October 28,

To all whom it may concern:

' UNITED "STATES PATENT onnion.

mm rrscn'nn, or nnnnm, GERMANY.

PBOC IESS FOR THE MANUFACTURE OF DUCTIIIE ELECTROLYTIC Be it known that I, FRANZ Freeman, chemist, asubject of the'German Emperor, refidin at 1 Hessischestrasse, Berlin, Germany, ave invented certain new and useful Improvements in Processes for the Manufacture of Ductile Electrolytic Iron; and I is not essential.

- perature ap do hereby declare the following to be a. full, .clear, and exact descri tion of the invention, such as will enab e others skilled in the art to which it appertains to make'and use the same.

M invention refers to the electrolytic 'pro notion of -'ron .andcomprises a specific manner of manufacturing objects consisting of such iron, such assheets, rods or wires.

The iron produced by electrolysis from aqueous solutions is generally of such hardness and brittleness that it can only be used for certain purposes in which ductility These inferior qualities of electrolytic iron produced according to processes hitherto known are due to the presence of hydrogen in the iron. Various methods have been su gested for the electrolytical production o an iron which is oorer in ydrogen and therefore more duct1 e. Maximowitsch (Zcitsch'r'ift fc'ir Elektrochemie, Vol. 11, fol. 52, 1905 produces such an iron froma solution of errous bicarbonate emplogiung very low current densities (not excee g .5 amperes per square decimeter) and working at ordinary temperatures.

Accordin ,to the German Patent No. 126839 an e ectrolytic iron is obtained from a hot solution of ferrous chlorid at a temroaching 70 C. by constant stirring of t e electrolyte or agitatin the cathode, at somewhat higher current ensities that is from 3 to 4 amperes per square decimeter. 'But it is explic1tly pointed out in this patent that the process can only be carried out successfully, if the ferrous chlorid is used without any foreign additions. I have now found that the quality of the electrolytic iron obtained from a soluthis raising of the tem tion of ure ferrous chlorid is greatly improved y raising the temperature. But

erature is not without detriment to the so ution, the" latter being changed in the same who, as the temerature is raised. These changes conslst m an oxidation of the solution by the oxygen of the air and in an increasing evaporation, so that it is practically impossible to work at atmospheric pressure at Specification of Letters Patent.

' Patented May 23, 1911. 191:9. Serial No. 524,217.

temperatures exceeding "90 C. According to my invention these disadvantages are overcome by means of addin certain inedients to the electrolyte w ich prevent its bein disintegrated. I use as such suitable ad itions very hygroscopic salts, such as chlorid of calcium, of magnesium, of aluminium etc. and I find that the said additions, especially at temperatures exceeding 70' (1., and'without stirring the electrolyte or agitatin the cathode, have not only no detrimenta effect, but, on the contrary, very materially iprove the ductility of the de- Eosit. This e ect could not be inferred from erman Patent No. 126839, in which it is explicitliy stated that good results are only obtaine with a pure solution of ferrous chlorid.

By addin substances such as the above mentioned roduce an electrolyte from which perfect y ductile iron is obtained at temperatures varying between 100 and 120 ,C., and at high current densities of more desired, exceed 20 amperes per square decimeter. As regards the current density, however, it should be noted that although the improved process makes it possibleto employ current densities of the value indi* cated, the process can be carried out successfull with currents of'much lower density. y this process I obtain an electrolytic iron of excellent chemical and hysical properties which in consequence of t e high current densities and the very .low voltages a plied is produced in a time sufiiciently s ort to enable me tomanufacture on a large scale and with great economy. The electrolytic iron thus produced is found useful for divers industrial purposes. Besides the wellknown steeling of the surface of engraved plates a l other processes may carried out and objects manufactured by employing electrolytic iron of an ensitv which may, 1f'

thickness.

in a very short time, for whic purposes other metals, such as copper, have hitherto been used.

The electrolytic iron obtained by my process is specially adapted for use in electromagnetic apparatus, since I findthat it far surpasses all kinds of iron hitherto known in magnetic permeability. In some cases, as when sheet iron or wire is wanted,

I find it more economical instead of producing directly by electrolysis such sheets or wires in the desired thickness, rather to produce thicker blocks or plates, which are then stretched to the desired shape and thickness by the ordinary processes of forging, or drawing.

As already stated above, I have found that rolling the ductility of the product increases withthe temperature of-the electrolyte... Thus, if it is desired to produce directly by electrolysis iron of the highest quality as to ductility and magnetic permeability, the temperature of the electrolyte should not be allowed to descend below 90 C. ,If lower temperatures are employed the product cannot be used with advantage for purposes in'whicli high ductility and magnetic permeability are essential. But I find that, if iron produced according to my present invention at temperatures between 70 and 90 0., is subsequently rolled or forged, it thereby acquires the desired qualities of high ductility and magnetic permeability in almost the same degree as with iron directly produced by electrolysis at higher temperatures. In

cases of this nature therefore one manner of carrylng out my invention consists in electrolyzing the above mentioned solutions at temperatures between 70 and 90 C.

thus producing comparatively thick blocks or plates and subsequently reducing said blocks or plates to the desired thickness and shape by any well known process of forging,

ture substantially-above C.

3. A process of producing electrolytic iron, which consists in adding a hygroscopic salt to a solution of ferrous chlorid and then subjecting the solution to electrolysis at a temperature substantially above 70 C.

4. A process of producin iron, which consists in ad ing calcium chlorid to a solution of ferrous chlorid, and then electrolyzingthe solution at a high temperature.

5. A. process of producing electrolytic iron, which consists in electrolyzing 11'0Il salts, with the addition of a hygroscopic substance, at a temperature substantially above 70 C. and with a current of relatively high density, as described.

6. A process of producing electrolytic iron, which consists in subjecting a solution of ferrous chlorid with an addition of highly hygroscopic substances to electrolysis at temperatures exceeding 70 C. and current densities of approximately '20 amperes per square decimeter.

7. A process of producing electrolytic iron, which consists in subjecting a solution of ferrous chlorid with an addition of chlorid of calcium to electrolysis at temperatures exceeding 7 0 (Land currentdensities of approximately 20 amperes per square decimeter.

'8. A process of producing electrolytic electrolytic iron, which consists in subjecting a solution of 450 weight units of ferrous chlorid, 500 weight units of chlorid of calcium in 750 weight units of water to electrolysis at temperatures between 100? and 120 C. and' current densities of approximately 20 amperes per square decimeter.

9. -A process of manufacturing ob ects of electrolytic iron, which consists of producing said products by precipitating iron from an electrolyte composed of iron salts, with an addition of hygroscopic substances, at temperatures exceeding C.

In testimony whereof I have .aflixed my signature, in presence of two witnesses.

FRANZ FISCHER. Witnesses:

HENRY HASPER, WOIDEMAR HAUPTv I