Positron Annihilation and Complementary Studies of Stainless Steel Exposed to Sandblasting at Different Angles

Abstract

Defect studies in subsurface zone in stainless steel 304 AISI samples exposed to sandblasting were performed using positron annihilation spectroscopy techniques. Samples were sandblasted with a different impact angle. Conventional experiments based on positrons emitted directly from the radioactive source allowed us to detect vacancies on the dislocation edges in all samples; however, the total depths of subsurface zones depended strictly on the impact angle, i.e., 35 lm for impact angle of 90°and about 12 lm for 30°. The complementary methods such as SEM and optical profilometry revealed also dependencies between the impact angle and roughness of the surface which are not observed in the variable energy positron beam examinations.

Positron Annihilation Studies of the Near-Surface Regions of Niobium before and after Wear Treatment

“…4a. It is worth noticing that VEP results obtained for niobium are significantly different than those obtained in similar conditions for Cu [13], Fe [28], or stainless steel [14,27]. Nevertheless, they are in qualitative agreement with the results obtained by Gu et al [29].…”

“…Our recent studies of subsurface zones created during dry sliding in Ti [10] and Zr [11] showed that they exhibited quite different defect depth distribution than in metals that have tribological application such as Fe [12], Cu [13], stainless steel [14]. We believe that studies of subsurface zone in metals, which are not used in tribojunctions can expand our knowledge about defects generation during sliding.…”

Impact of Impulse Shot Peening Parameters on Properties of Stainless Steel Surface

“…These lifetimes are comparable or even slightly greater to those observed in the stainless steel subjected to dry sliding [6], while sandblasting [7] has effect similar to the one observed in the grinded sample. The data on the mean lifetimes and Vickers hardness numbers measured with changing E, j and 1/D for shot peened samples are compiled in τ mean -HV coordinate system in Fig.…”

“…Our previous research has shown that unalloyed, bearing and carburizing steels as well as aluminum and titanium alloys, which were subjected to SP, can be successfully investigated by PALS [4,5]. Also the PALS studies of the surface layer of the stainless steels treated by dry sliding [6] and sandblasting [7] allow to expect that this technique is suitable for similar steels.…”

Development of Positron Annihilation Spectroscopy at Joint Institute for Nuclear Research

“…During the years 2014-2018 about 80 runs for PAS were performed at the LEPTA facility. The samples of irradiated metals [7][8][9][10][11] as well as subjected to a surface treatment [12,13] were subsequently investigated by the DBAL PAS method.…”