Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 15 No. 6 December 2005|
（College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China）
Abstract: Sebisty effect describes the unusual fact that the thickness of the hot-dip galvanizing coating on the steel containing 0.12%-0.25% silicon decreases with increasing temperature of zinc bath. The microstructures of hot-dip galvanized coatings on silicon-containing steels (0.14%Si) immersed in zinc bath at 723K and 753K were analyzed. It is found that the thickness of η and ζ layer decreases with the increase of temperature of zinc bath and Г layer changes from discontinuous layer (at 723K) to relatively continuous layer (at 753K). The improvement of the fluidity of zinc bath due to the rising temperature of zinc bath makes η layer thinner. Moreover, the existence of relatively continuous Г layer and the acceleration of the dissolution of ζ layer to zinc bath co-lead to the decrease of the thickness of ζ layer with increasing temperature.
Key words: zinc coatings; Sebisty effect; intermetallics; galvanized steel