The influence of applied potential on the erosion-corrosion behavior of AISI321 stainless steel in acidic slurry medium

Abstract

The influence of applied potential on the erosion-corrosion (E-C) behavior of AISI321 stainless steel in 10% H 2SO 4 + 15% corundum sand (60 mesh) acidic slurry was investigated using a modified slurry pot apparatus. The surface morphologies of E-C specimens at various applied potentials were observed by scanning electron microscopy. The results showed that cathodic protection could significantly decrease E-C rate, and the cathodic protection efficiency could be 73.6%. The influence of applied anodic potentials on the E-C behaviors could be classified as the following three types: 1. A. The E-C rate increased sharply in region I (a little more positive than free-corrosion potential); 2. B. The E-C rate decreased significantly in region II (stable passive region), and the anodic protection efficiency could be 64.5%; 3. C. The E-C rate increased again in region III (transpassive region) because of intergranular corrosion. The appropriate potential range of anodic protection is 0-0.8 V (SCE).