Growth behavior and properties of Zn�VAl pack cementation coatings on carbon steels
Journal
Surface and Coatings Technology
Journal Volume
306
Pages
455-461
Date Issued
2016
Author(s)
Abstract
Zn–Al pack co-cementation was performed on medium carbon steel in a pack mixture containing Zn and Al powders with NH4Cl as activator. An Fe–Zn layer was formed first during pack co-cementation. Fe–Al phases then nucleated locally on the surface of the Fe–Zn layer. With continued reaction, a complete Fe–Al layer was formed and grew at the expense of the Fe–Zn layer. The Fe–Zn was compact, but the Fe–Al layer was porous. The Fe–Al layer had better high-temperature oxidation resistance, while the Fe–Zn layer had better corrosion resistance in chloride solution. Based on microstructural evolution and the chemical reactions associated with Zn–Al pack co-cementation, the growth behavior of Zn–Al pack coating on steel was discussed in detail.
Type
journal article