EROSION\|CORROSION BEHAVIOR OF DUPLEX STAINLESS STEEL IN FLOWING 3.5% NaCl SOLUTION

The erosion corrosion behavior of 0Cr25Ni6Mo3CuN duplex stainless steel in flowing 3.5% NaCl solution were studied with emphasis on its kinetic process. It was found that the erosion corrosion rate of duplex stainless steel in flowing 3.5% NaCl solution was increased with increasing the flow velocity, and that there was a critical flow velocity above which the erosion corrosion rate was speeded up abruptly. Furthermore duplex stainless steel suffered from serious erosion corrosion if the temperature of solution was increased. From the kinetic process of erosion corrosion it was showed that the erosion corrosion of duplex stainless steel was mainly controlled by passivative process of anode, on which the diffusion or migration rate of ions in film at interface was the key step . The results also showed that the duplex stainless steel in flowing 3.5% NaCl solution at ambient atmospheric temperature would be resistant to erosion\|corrosion even if flow velocity was up to 15m/s. However, it should be careful for the duplex stainless steel to be applied in flowing 3.5% NaCl solution at high temperature when flow velocity was above the critical flow velocity.