6533b830fe1ef96bd1296ec8
RESEARCH PRODUCT
Studies of the Phosphatization of Steel and its Corrosion Products
W. Meiselsubject
Materials scienceStandard hydrogen electrodeMetallurgyElectrolyteengineering.materialPhosphateCorrosionchemistry.chemical_compoundchemistryCoatingReagentengineeringPhosphoric acidElectrochemical potentialdescription
The reaction of phosphoric acid with steel is a basic process in many technological procedures. A typical example is the pretreatment of steel surfaces for the application of coatings. The aim of the treatment is to clean the surface, to produce a homogeneousr tight, and smooth cover and to provide a reliable adhesion between the steel substrate and the coating. This example points out that the phase composition of the layer formed is of great interest, and that reactions with residues on the surface, such as oxides and corrosion products, have to be considered, too. The same holds for phosphate layers formed in order to modify the mechanical or corrosion behavior of steel surfaces. Because of the electrolytic character of these processes, in addition to the usual reaction parameters, such as temperature, concentration, and time, the electrochemical potential of the sample has to be controlled during the reaction. In these examples, diluted phosphoric acid, phosphate solutions, and mixed solutions are used. Solutions of higher concentration are used as “rust transformers”. An example for the use of concentrated phosphoric acid is its application for the removal of rust from vessels, tubes, etc. If the corrosion products to be removed are contaminated, as for instance in nuclear power plants, a minimum quantity of the reagent needed for the treatment is desired.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1986-01-01 |