Blueing

Burning of steel is a chemical process usedto obtain on the surface of the steel part of a thin protective film of iron oxides Fe3O4. The name was received because of the characteristic color of the detail after processing (bluish-black, raven wing), also called "blackening" or "bluing" in the general case, regardless of color - "oxidation". The resulting film passivates the surface and protects the part from atmospheric corrosion and the effects of other corrosive media.

Before the blasting of the steel, the partpre-prepared, rust-cleaned mechanically, polished, degreased and etched in acid solution. Degrease can be thinner or alcohol. Etching is needed to remove all excess oxides from the surface, leaving bare metal.

The easiest way is to blaze oil to oil.There are different methods, but the meaning is simple: a thin layer of oil is applied to the part, after which it must be heated to 300-350 ° C. Oil, burning, leaves an oxide film on the surface. From the first time, a uniform coating is not obtained, so the process is repeated until the desired result is achieved. It is important to achieve uniform heating, otherwise the film will become stained, and do not overheat the part, as it can be deformed or released. Many make the mistake and lower the heated part in the oil, it's wrong. It is necessary exactly the reverse: first smear, then warm. Oil is used by anyone, from sunflower to transmission or machine. This blasting of steel has a low coating strength. It is suitable only for decorative protective purposes.

Burning of steel with the use of iron vitriol, iron chloride and nitric acid

For this, 15 grams per liter of wateriron, 30 g of vitriol and 10 g of acid. On the product dropped into the solution, a rusty coating will form, it must be periodically removed with a brush and continue dipping until the required color of the oxide film is obtained. Now practically in any city there is a store selling chemical reagents, so it's relatively easy to get them.

Burning of steel with the use of chrome(potassium dichromate). For this, a liter of water is diluted 200 grams of chrome powder and immersed in a solution of the part for 20-30 minutes. After removal from the solution, it must be dried at high temperature (in the oven or over the coals). The process should be repeated until a uniform blue-black color is obtained. Then the part is wiped with an oiled rag. Hrompik - a reagent is very common, it is used in the leather industry.

For the blasting of armsheating 1 part by weight of antimony trichloride with 3 parts of olive oil. Then the mixture is applied to the part and left for a day. The process is repeated 10-12 times, after which the barrel is washed, dried and polished. The color turns greenish brown.

As can be seen from the above, the bluing of steel inhome conditions - quite feasible and uncomplicated process. It can be used for any steel products in cases where other methods of corrosion protection, for example, painting, are not applicable.