The Influence of the Chemical Composition of a Zinc Bath upon Corrosion Resistance of Coatings Obtained on Sebisty Steel

摘要

In the paper the results of tests defining the influence of the chemical composition of a zinc bath on the corrosion resistance of coatings obtained on Sebisty steel are presented. The coatings for the tests were produced on Sebisty steel with the content of silicon of 0.18 wt.% in Zn-AlNi, Zn-AlNiPb and Zn-AlNiBiSn baths. Corrosion resistance of coatings obtained in alloy baths was compared with the corrosion resistance of a coating obtained in a bath of pure Zn. The structure of coatings has been developed, the chemical composition of structural components of the coating and the coating thickness have be established. Corrosion resistance of the coatings was defined by comparative methods in a standard corrosion test in neutral salt spray. The tests were carried out in accordance with the EN ISO 9227 standard. It has been established that alloy additions to a zinc bath have impact upon corrosion resistance of obtained coatings. The addition of Pb results in a decrease in corrosion resistance of a coating obtained on Sebisty steel.