MODIFICATION DE SURFACE D’ACIERS INOXYDABLES PAR EXPOSITION A UN PLASMA D’AIR HUMIDE

Abstract

Austenitic 304L and 316L stainless steel disks are exposed to the r eactive species formed in a low temperature gliding arc plasma in humid air under atmospheric pressure. The plasma treatment which induces corrosion phenomena and phase transformation is electrochemically controlled by following the corrosion parameters E corr and I corr . They respectively increase and decr ease with the treatment time t. X- ray diffraction analysis of the treated samples shows a decrease of the amount of the ferrite phase ( α -Fe) for the 304L steel vs t, suggesting the transformation of the phase, and its complete disappearance after 1 hour for the 316L steel. The austenitic phase ( γ -Fe) remains predominant for both samples. The gliding arc treatment of stai nless steel surfaces in humid air in creases their corrosion resistance in aggressive environments by forming improved barrier layers.