Influence of Nano Substructure of Cementite Lamellae on the Mechanical Properties of Galvanized Pearlitic Steel Wires

Abstract

It is well known that Si improves the mechanical properties of hot dip Zn-galvanized pearlitic steel wires. However, the improving mechanism is still not clear. Thus, hot dip galvanized pearlitic steel wires were investigated by TEM observation from the viewpoint of the sub-structure of cementite lamellae. The presence of nano sized substructure was observed in electrolytically extracted cementite lamellae after hot dip Zn-galvanization process. The mean diameter of cementite sub-structure in the high tensile strength Si-containing pearlitic steel is much finer than that in a conventional low Si steel. Hence, it is concluded that Si improves the mechanical properties of galvanized pearlitic steel wires by refining the substructure of cementite lamellae.