Visual observation
Failed wire samples were observed visually under macro dual zoom microscope (see Fig. 1a). In the case of drawn wire
samples, finger nail fractures were observed at the broken ends. The fresh fracture surfaces were very shiny, indicating the
possibility of hydrogen embrittlement [1]. Deep surface tearing was also observed from the above figure in all the wire
samples. Point 2, 3 and 4 are showing the transverse crack on the drawn wire piece.
Fig. 1b and c reveals the transverse cracks on the surface that may be due to the huge pressure build-up of hydrogen in
interstitial sites. The present investigation was carried out to confirm embrittlement either due to metallurgical problems or
due to the H concentration in material. Further, metallographic investigation was also done to characterize the failure.