Corrosion Behavior of Ultrafine Grained Austenitic Stainless Steel

Abstract

Ultrafine grained AISI 304 steel was produced by low temperature recrystallization after subzero working, and the corrosion behavior of these steels was investigated in various corrosive environments. The general corrosion rate increased with decreasing grain diameter. On the other hand, the resistance to intergranular corrosion, pitting corrosion, and stress corrosion cracking increased with decreasing grain diameter. The pitting corrosion and stress corrosion cracking resistance of ultrafine grained AISI 304 steel was particularly improved by grain refining. This increase of local corrosion resistance seems to be related to an increase of grain boundary density per unit volume and the resultant film destabilization.