A review on metallurgical features of hot-dip aluminized steel

Abstract Among the various surface modification processes, the hot-dip aluminizing process has increasingly evoked considerable attention. This method has proved to be commercially cost-effective and technically better than galvanizing. In contrast to hot-dip aluminized steel components, galvanized components cannot be used in service conditions at elevated temperatures. During the last few years, intensive research by researchers has yielded new insights into metallurgical aspects of aluminized coating in as-dipped and annealed condition. The present review gives a bird’s eye view of the hot-dip aluminizing process, from the early years of its inception to the current research on aspects of the aluminized coating. The progress of research on thermodynamic studies, phase equilibria, phase identification, and their crystallographic features have been traced in this attempt. This review is not restricted to briefing the research performed so far but also points out several issues of discrepancies among the results of the published literature. Special emphasis has been given to the phase development in the coating during annealing and the increasing horizon of application of hot-dip aluminizing to alloy steels in hot stamped conditions. Reference has also been made to state-of-the-art topics embracing the current research on computer simulation software and sophisticated experimental techniques. However, lower surface hardness and economy restrict the wide application of the hot-dipping process.