Effect Of Crevice And Hydrostatic Pressure On The Corrosion Behaviors Of 316L Stainless Steel

Effect of crevice and hydrostatic pressure (from 1atm to 80 atm) on the corrosion behavior of 316L stainless steel (316L SS)at room temperature were investigated by electrochemical measurements, microscopy observation and nanoindentation. Potentiostatic measurements revealed that the corrosion process of 316L SS consists of three stages:the formation of passive film, metastable pits generation and repassivation, stable pits growth. The experimental results were analyzed based on stochastic and statistical method. In case of crevice, corrosion resistance of 316L stainless steel dreased, characterized by different corrosion generation mechanism, the decreasing critical transition size of metastable to stable pit and the increaseing development rate of stable pitting.And as for the effect of hydrostatic pressure on corrosion behavior of 316L stainless steel in NaCl solution, experimental results revealed that the increasing hydrostatic pressure increased the pitting corrosion resistance of 316L SS, distinguished by the increase of critical pitting potential (Ecirt). The results also demonstrated that hydrostatic pressure had three effects on the corrosion behavior of 316L SS:(1) the increasing hydrostatic pressure strengthened the passive film; (2) the increasing hydrostatic pressure retarded the B1 process (birth and death stochastic model) and accelerated the A3 process (parallel birth stochastic model); (3) the pitting growth probability decreased with the increase of hydrostatic pressure.