Preheated zinc in the fight for durability partsNovember 28, 2017
With the development of the metalworking industry, a large number of technologies to protect metal products from the natural process of destruction of the metal structure, due to the negative effects of moisture, oxygen and other aggressive environmental factors.
One of the most effective methods to protect metal structures from corrosion is their hot-dip galvanizing.
The principle of this method is that the surface of the product is applied anti-corrosion protection in the form of a thin layer of zinc, which prevents direct contact of the metal base with aggressive agents. Iron or steel products treated in this way acquire resistance to rust processes for a period of up to 70 years, without the additional need for their repeated treatments, which is an undoubted advantage of this method.
How does galvanizing of metal structures in production occur?
In order for the iron billets to acquire anti-corrosion properties, they must be subjected to the following operations:
- Removal of contaminating elements from parts by mechanical means or by sand blasting equipment;
- Then it is required to degrease the surface of the blanks from chemicals in order to ensure a better contact of the protective zinc coating with the substrate;
- Next, the part is washed from chemical residues;
- Using etching processes, it becomes possible to clean the surface of the product from oxides and rust, where, thanks to acid treatment, the metal moves one more step to the next preparatory stage;
- The end point before the treatment of hot zinc is the stage of fluxing blanks, which prevents oxidation of the metal as a result of its interaction with the ambient air;
All parts, at the end of the preparatory phase, should be dried, where they are exposed to high temperatures in special ovens. There, residues of the liquid are removed from the blanks, which may adversely affect the quality of the coating.
The final stage of all the completed manipulations is the actual galvanizing procedure, during which parts are placed in a container with zinc heated to 420 degrees Celsius. There is the filling of all the microcracks and surfaces of this coating. At the exit, these samples have a protective layer that has the function of self-healing in case of damage to any area. And despite the fact that the samples obtained have an unsightly gray appearance, their wear resistance during operation still prevails over the aesthetic side of the issue.