Impact of Abradant Size on Damaged Zone of 304 AISI Steel Characterized by Positron Annihilation Spectroscopy

Positron annihilation, electron microscopy, and optical profilometry studies of steel 304 AISI exposed to blasting with different size of abradant, i.e., alumina and glass have been reported. The size of abradant particles has a direct impact on the roughness which changed from 0.7 μm to about 5 μm. Positron lifetime measurements revealed the existence of defects associated with the dislocations in samples processed with a smaller medium. In the case of blasting with aluminum oxide particles with a diameter of 250 μm, monovacancies were detected in processed specimens. The defect concentration induced by blasting decreases with the increase of the depth from the surface, and it depends on the abradant particles’ size.