IS A COATING PART OF THE SUBSTRATE - THE CASE OF VANADIUM CARBIDE ON STEEL

Metallic surfaces, especially that of steel, are generally protected b y various types of coatings. This paper presents some of the results o f CEMS studies currently being made on mild steel substrate coated wit h a thin layer of vanadium carbide (VC). CEMS studies were done before and after coating. The internal magnetic field was found to be orient ed at an angle of 48 degrees with respect to the transverse surface of the steel sample. After coating with VC at 950 degrees C, this value was reduced to 39 degrees. Molecular orbital calculations indicated th at the electron density along the surface of the steel is significantl y changed when the VC layer is formed, which leads to the changes in t he magnetic field directions that are observed. The experimental data therefore reveal that vanadium from the coating diffuses into the iron substrate.