1991 Volume 77 Issue 11 Pages 2000-2006
The chemical state of the water in the hydrated chromium oxide film on Tin Free Steel (TFS) was studied under atmospheric pressure using Fourier Transform Infra-red Spectrometer (FTIR).
Following results were obtained;
(1)Emission spectra can be measured at as low as 50°C where a dehydration commences. The characteristic bands in emission spectra agree well with those in reflection-absorption spectra.
(2)A broad and weak absorption is observed at 950 cm-1. It is attributed to the water in the film, because it disappears when TFS is heated at 200°C. On the contrary, the absorption caused by bending vibration in HOH at 1 590 cm-1 remains even after heating at 300°C. It is therefore presumed that there are two chemical states of the water in the film, and the absorption at 950 cm-1 to the water which is free from the chemical structure of the film.
(3)A clear correlation is found between the lacquer adhesivity of TFS and the ratio of the absorption intensitys at 1 590 cm-1 and 950 cm-1. This relation can be utilized for evaluation of the lacquer adhesivity.
