US1574823A - Method of and apparatus for treating metal - Google Patents

Description

March 2 ,1926, 1,574,823

W. C. KRONQUEST METHOD OF AND APPARATUS FOR TREATING METAL Filed May 27, 1925 I I Q n 2 E {M m i R N MU g mi 2 Q i W? EN 5R- 5 r \p I R [Wm 6W0 mi N ZZZ following is a specification.

l atented Mar. 2, 1 926. i

1 UNITED STATES PATENT OFFICE.

WILLIAM C. KRONQUEST, OF, CHICAGO, ILLINOIS, ASSIGNOR T0 ACME STEEL COMPANY,

OF CHICAGO, ILLINOIS, A. CORPORATION OF ILLINOIS.

METHOD or an!) ArPAnA'rus son 'rnna'rrno iitn'mn.

' Application filed May 27, 1925. Serial No. 88,148.

To "all whom it may concern: Tension is maintained on the strip throu h- Be it known that 1, WILLIAM C. KnoN- out its length so as to keep it at a definite QUEST, a citizen of the United States, residheight in the tanks, g ing at Ghicago, in the county of Cook and The pickling fluid in the tank 10 consists State of Illinois, have invented a new and preferably of a solution of sulphuric acid useful Improvement in Methods of and Apin water such as is commonly used in pickparatus for Treating Metal, of which the ling metal. Beneath the metal strlp A in the pickling tank are placed a series of This invention relates to a method of and plates 24 of lead or other electrical conductapparatus for treating metal, particularly ing material which will not be acted upon sheet steel strips or the like prior to electi by the acid and these are connected to the plating, coating or working. c

In the process of cleaning metal with acids, there is a strong tendency for it to adsorb and retain gases, especially hydro gen. Such a gas when permitted to remain in the metal during the plating operation,

negative pole of a source of current 25, the positive pole being connected to the middle rollers 13, 16, 17 and 20L The sulphuric acid solution acts as a pickling agent, thoroughly cleaning the surface of the metal strip A therein. At the same causes blisters to form under the plating. time thestrip itself A serves as the anode It also changes the physical characteristics and the lead bars as the cathode of an elecof some metals, as steel, which becomes brittrolytic cell which decreases the amount of tie when hydrogen is thus occluded. I I

The primary object of this invention, is to provide a process of and means fordecreasing the adsorption of gas at this time by the metal to be plated or otherwise treated.

Another object is to provide a process for thoroughly cleaning or picking the, metal. v

These and other objects, which will hereinafter appear are accomplished by this invention which is fully described in the-following specification and shown in the accompanying drawing in which the figure is a diagrammatic vertical section through the pickling and electro-plating tanks.

The embodiment illustrated comprises a pickling tank 10, a washing tank 11 and an electro-plating tank 12 arranged in a convenient series so that a strip of sheet metal A may be fed continuously through them. This strip A passes over a metal roller 13 which lies outside the pickling tank 10, thence down under the 'rollers 14 and 15 which lie beneath the surface of the pick ling fluid in the tank 10, thence over rollers 16 and 17and then under rollers 18 and 19 which carry the strip beneath the surface of the washing fluid of the tank 11.

The strip then passes over a roller 20 and into the electro-plating tank 12 where it passes under rollers 21 and 22. From this tank. it passes out over a roller 23 and thence to a reel or the like (not shown),

"the metal strips serving as the anode.

lead or other material which are connected to the negative pole of the source of current 25. The sheet metal plate then passes over a roller 20 and into the electro-plating tank 12. It is desired that the metal strip shall remain moist throughout the time it is passing from the pickling tanklO to the washing tank 11 and again from "the washing tank 11 to the electro-plating tank 12. To prevent drying, particularly after leaving the washing tanl the solution therein is kept quite cold so as to prevent eva oration during the time the strip is passing rom one tank to the next. To do this and to dilute the acid which,is being carried in by the strip A, a constant streamgof cold water is fed through a pipe 27, the level of the water in the tank 11 being kept to the level of the overflow 28. The pickling solution however may be heated.

The metal strip A isthen electro-plated manner as by means of the metal roller 23 which is connected to the negative side of the generator 29 While the anode plates 30 are connected to the positive side of the generator.

It will be understood that-the explanation of the action of the herein described process is believed to be the true one but that the invention is not to be limited thereby. Moreover this process, while primarily intended to be used preparatory to electroplating, may also be use for pickling metal prior to painting, rolling, stamping or other suhse uent operations wherein the -preseucc of hydrogen in the metal is objectionable.

The process illustrated is for a continuous sheet but it is apparent that it applies to non-continuous sheets and to castings or the like.

While I have shown and described but a single embodiment of this invention, it is to be understood that it is capable of many modifications. Changes therefore in the construction and arrangement may be made which do not depart from the spirit and scope of the invention as disclosed in the appended claims.

claim:

1. The method of pickling metal consisting of immersing the metal in a solution ot'acid and water, and passing an electric current through said metal while so immersed, the metal forming the anode plate of an electrolytic cell thereby decreasing the amount of hydrogen adsorbed thereby, the cathode being a material which does not combine chemically. with said acid under ordinary conditions.

2. The method of pickling metal consisting of immersing the metal in a solution of acid and water, and passing an electric current through said metal while so immersed, the metal forming the anode plate of an electrolytic cell thereby decreasing the amount of hydrogen adsorbed'thereby, the cathode plate being lead.

3. The method of electro-plating a continuous strip of metal consisting of passing the metal strip through a cleaning solution, simultaneously substantially preventing the adsorption of hydrogen by said strip, washing said strip, and passingit intothe elec-.

tro-plating tank.

4. The method of electro-plating a continuous strip of metal consisting of passing the metal strip through a cleaning solution, simultaneously substantially preventing the liberation of hydrogen on said strip, washing said strip, and passin ,it into the electro-plating tank while said strip is still wet.

5. The method of electro-platin a continuous strip of metal consisting o passing the metal strip through a cleaning solution, simultaneously substantially preventing the liberation of hydrogen on said strip, washing said strip, and passing it into the electro-plating tank, the washing solution being cold so as to prevent evaporation before the wet strip enters the electrolyte of the plating tank.

6. Apparatus for preparing metal for subsequent operations comprising a tank containing an acid pickling solution in which the metal is immersed, and means for passing an electric current through said metal to decrease the adsorption of hydrogen by said metal.

7. Apparatus for preparing metal for subsequent operations comprising a tank containing a solution of sulphuric acid in which the metal is immersed, and means for substantially preventing the adsorption of hydrogen by said metal.

8. Apparatus for preparing metal for subsequent operations comprising a tank containing a solution of sul 'huric acid in which the metal is immerse means for substantially reventing the liberation of hydrogen on t e surface of said metal, and means for washing said metal.

9. Apparatus for cleaning and electroplating a continuous strip of metal comprising apickling tank, means therein for substantially preventing the adsorption of hydrogen by said metal strip which is to be plated, means for washing said strip, and

means for electrolating said strip.

10. Apparatus or cleaning and electroplating a continuous strip of metal comprising a pickling tank, means therein for substantially preventing liberation of hydrogen on the surface of said metal strip which is to be plated, means for Washing said strip, means for substantially preventing the liberation, of hydrogen on said strip while being washed, and means for electro-plating said strip.

11. Apparatus for preparing metal for subsequent operations comprising a. tank containing a solutionof sulphuric acid in which the metal is immersed, an electrical conducting material inactive to sulphuric acid at normal temperatures, and a source of electrical current connected to said plate and material so that hydrogen will be liberated on said material.

WILLIAM C. KRONQUEST.

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