Effect of temperature and zinc concentration on zinc coatings deposited with pack cementation

Abstract

Zinc coatings are proved to be corrosion resistant as they react with atmospheric compounds forming an adherent film on their surface. This work investigates the feasibility of zinc deposition on low alloy steels by pack cementation at temperatures from 380 to 450°C. The effect of zinc concentration in the pack powder is also examined to increase the corrosion resistance of the coating without affecting its mechanical properties. The duration of the process was stable at 2 h. From this research it was finally observed that the formation of the zinc coating begins over 390°C and that the zinc content affects exponentially the coating thickness, but not the phase distribution of the as produced coating which refers to γ-Fe₁₁Zn₄₀ and δ-FeZn₁₀ phases of the Fe–Zn phase diagram.

Keywords:

• PACK CEMENTATION
• ZINC COATINGS
• METALS AND ALLOYS
• X-RAY TECHNIQUES
• ELECTRON MICROSCOPY