Barkhausenov šum po dynamickom guľôčkovaní duplexnej ocele AlSi 318

Abstract

This paper deals with surface integrity and the corresponding Barkhausen noise after shot peening of duplex steel AlSi 318 under variable shot-peening conditions such as number of passes and applied air pressure. Surface state is investigated from the point of view of surface roughness and surface plastic deformation. Barkhausen noise is decreasing along with increasing surface coverage as well as increasing air pressure. The duplex matrix is considered being stable with respect of volume fraction between austenite and ferrite and the whole Barkhausen noise signal originates from ferromagnetic ferrite. Progressively developed plastic deformation increases dislocation density in the surface as a result of surface bombardment by shots which in turn shift Barkhausen envelopes into higher magnetic fields.