The influence of reduced pressure in the quality of hard chromium coatings was investigated. The reduced pressure method is based on a Finnish invention and it has been developed in order to produce chromium coatings, with higher quality.
Muttilainen, E., & Tunturi, P. (1984). Hard chromium plating under reduced pressure improves corrosion resistance. Anti-Corrosion Methods and Materials, 31(3), 13 - 15. https://doi.org/10.1108/eb007242