Farahnaz Haftlang - Faculty of Metallurgicl and Materials Engineering , University of Semnan, Semnan, Iran
Ali Habibollahzade - Faculty of Metallurgicl and Materials Engineering , University of Semnan, Semnan, Iran
Mahmoud Heydarzade Sohi - School of Metallurgy and Materials, College of Engineering, University of Tehran, Tehran, Iran

This study aims to investigate the feasibility of aluminizing medium carbon steels at temperatures above and below melting point of aluminium by pack cementation process. Packs activated by AlCl3 and NH4Cl were used to carry out coating deposition experiments at 650, 850,900 and 950°C in an attempt to identify suitable activator for the intended pack aluminizing process. Once this was achieved, a series of further experiments were undertaken to investigate the effects of pack composition, deposition temperature and time on the coating growth process. The deposition temperature was varied from 650 to 950 °C and deposition time from 1 to 16 h. Within the ranges of these parameters, it was observed that these parameters only affected the coating thickness, but not the surface Al concentration and with the packs activated by AlCl3, the coatings formed via an inward reactive Al diffusion mechanism, which led to the formation of a surface Fe14Al86 layer and an inner Fe2Al5 layer

cementation process, pack composition, temperature and time of deposition