EFFECT OF THIOSULFATE ION ON PITTING OF NICKEL - BASED ALLOY 671 IN SODIUM CHLORIDE SOLUTION
S2O2-3对Ni基合金671在NaCl水溶液中的点蚀行为的影响

In sodium chloride solution containing thiosulfate ion,pitting behavior of nickel-based alloy 671,which will be used as candedate construction material in supercritical water oxidation(SCWO) devices,was investigated by electrochemical testing methods.The results show that in plain sodium thiosulfate solution alloy 671 is immune to pitting.While a critical chloride ion concentration for pitting commence of alloy 671 is exist in sodium chloride solution,and where the corrosion resistance of alloy 671 is higher than nickel-based alloy 690.Furthermore with increasing the addition of sodium thiosulfate into sodium chloride solution,the pitting corrosion of alloy 671 is obviously inhibited.This characteristic makes alloy 671 competitive as an SCWO construction material.