PREDICTION OF THE DELAMINATION IN THE PEARLITIC STEEL FILAMENTS BY 3 DIMENAIONAL ATOM PROBE TOMOGRAPHY

We have tried to find out the critical factor governing the delamination in the pearlitic steel filaments. Steel filaments were fabricated depending on the carbon content from 0.72 to 1.02 wt.%. The delamination was identified by a torsion tester specially designed for thin-sized wires and scanning electron microscopy. The results showed that as the carbon content increased, the number of twists to fracture decreased, and the delamination only occurred in the filament with 1.02 wt.% C. In order to elucidate this behavior, the microstructure of the filaments was observed using advanced analysis techniques such as 3 dimensional atom probes tomography (3-DAPT).