DE209805C - Verfahren zur erzeugung einer gegen rost widerstandsfähigen schicht auf eisen- oder stahlgegenständen - Google Patents

Description

IMPERIAL

PATENT OFFICE.

or steel objects.

ao. March 1883

the priority

In order to make iron objects resistant to rust, it has already been proposed that to expose them to the action of metaphosphoric acid (ice phosphoric acid) and z. B. for iron wire a solution of this acid in. Water to use. A protective layer is then created on the metal object metaphosphorsaureni iron. According to the inventor, avoiding the with the use of metaphosphoric acid associated problems a better rust protection Achieve when the objects to be protected are more ordinary with a dilute solution Phosphoric acid to be treated.

The metal object is immersed in the dilute solution of ordinary phosphoric acid. It has been shown that the duration and strength of the chemical action on the metal can be regulated as desired, if the acid bath contains an addition of metallic iron (filings, phosphoric acid iron oxide) or the like). But it goes without saying that such an ingredient is added not necessary for carrying out the procedure. That according to the invention Bath prepared from a dilute solution of ordinary phosphoric acid can also be used are decomposed by means of the electric current.

A mixing ratio for the bath is j 35

for example the following: iron in the form of filings or powder 28 g, ordinary Phosphoric acid 113 g, water 4.5 kg.

The solution is placed in an enamelled iron container, where it is heated to the boiling point. * The metal or the object in question is then immersed in the hot bath after careful cleaning, whereupon the solution to some extent, e.g. B. is attenuated to ¹ J _{7 of} the original volume. The objects are then taken out of the bath and can be oiled for further use after careful wiping and drying.

The layer that is deposited on the surface of the metal object during this treatment and consists of phosphoric acid iron can, if necessary, by repeating the Process. For the same purpose, even after partial evaporation of the bath, a further amount of phosphoric acid can be used be added with iron arrow chips or powder. The dilution of the solution and re-evaporation then takes place again '.

Any spongy deposits that form on the protective layer or the treated Object can be removed after removing the object from the acid bath

55

(3rd edition, issued on April 3rd igi3.)

Easily remove by washing or splashing with warm or cold water.

As soon as the color of the protective layer takes on any shade, the metal counter-

After completion of the acid process, it would stand in a cold or boiling solution, the sulphides, Contains tannin and similar substances. Such substances can Incidentally, already contained in the acid bath.

ίο However, caution is necessary here because otherwise the protective effect of the phosphoric acid iron layer is easily impaired.

To the. Any mechanical devices can be used to carry out the method will. A wire sieve is used to hold the objects, Muslin, linen, wool fabric or the like or a vessel with openwork walls possible. The small parts can then

ao chen, z. B. the iron filings, not immediately to the treated object, but the solution liquid has free Access. Such a sieve or vessel can be combined with a rotatable drum, in order to effectively expose all surfaces of the treated object to the action of the solution and prevent uneven deposits. If the receptacle is rotatable, the sieve-like cage can be omitted

Will. .

Claims (4)

Patent Claims: . i. Process for generating a counter Rust-resistant layer on iron or steel objects, characterized that the metal object is treated with a dilute solution of ordinary phosphoric acid containing forms a protective layer of phosphoric acid iron on the metal object. 2. The method according to claim 1, characterized in that the dilute solution ordinary phosphoric acid in which the metal object is immersed by means of of the electric current is decomposed to the metal object with phosphoric acid Plating iron. 3. Ancestors according to claim i, characterized in that the dilute acid bath an addition of metallic iron (filings, iron oxide, etc.) receives. 4. The method according to claim 1 and 3, characterized in that the acid bath mixed with metallic iron is heated to the boiling point before the metal object is immersed and is ^{evaporated to about 1} Z _{7 of} the original volume after the object has been introduced.