DBPapers
DOI: 10.5593/sgem2011/s18.109

ENVIRONMENTALLY FRIENDLY SOLUTION FOR THE HOT DIP GALVANIZED COATINGS

AUTHOR/S: T. RADU, A. CIOCAN, S. BALINT, V. DRAGAN
Monday 1 August 2011 by Libadmin2011

11th International Multidisciplinary Scientific GeoConference SGEM2011, www.sgem.org, SGEM2011 Conference Proceedings/ ISSN 1314-2704, June 20-25, 2011, Vol. 3, 53-60 pp

ABSTRACT

Lead-free solutions for protective coatings as an alternative for ecological galvanized
steel sheets obtaining were studied in this paper. The lead from zincing baths was
eliminated and replaced with bismuth as non hazardous elements. Also other alloying
elements (nickel, tin, and aluminium) in zinc melts were added. The making technology
of these galvanizing free-lead alloys was established in accordance with alloying
elements properties. The technological conditions for obtaining zinc-bismuth coatings
with variable bismuth contents are presented. Also the influence of this element on the
characteristics of the melt and on the layers properties in correlation with the process
parameters is discussed. The influence of the bismuth content on the morphology of the
coating layer’s surface (by macroscopic and microscopic analysis) and the
microstructure of the coating were studied. The good corrosion behavior of the lead-free
coatings was confirmed by electrochemical tests in an environment similar to a
maritime environment.

Keywords: alloyed zinc bath, zinc-bismuth coatings, corrosion