| It is essential and significant in the extreme for water resources exploring and water conservation to recycle and reuse the industrial effluent. The susceptibility of pitting corrosion and stress corrosion cracking (SCC) were studied respectively in NaCl solution, low and high hardness simulated circulating cooling water containing chloride ions by means of in-situ electrochemical tests under constant strain, slow strain rate tests (SSRT) and scanning electron microscope (SEM). Then the influence on corrosion resistance of chloride concentration, water treatment agent and strain were investigated. The mutation plot of pitting potentials and the SCC critical concentration for 304 stainless steel in simulated circulating cooling water were confirmed. So the applications were based and inducted by these experimental data.Based on the research contents, several results were required as follows:(1) With the increase of chloride concentration, the pitting potential E_b were deceased, herein the susceptibility of pitting corrosion was more severe; and plastic lost was manifold, the susceptibility of SCC was augment, too.(2) The critical chloride concentration scope of SCC in low hardness circulating cooling water was 300mg/L-600mg/L, when the chloride concentration was higher than 600mg/L, SCC could occur. However, the water treatment agent Rp-98H has less improvement on SCC inhabitation.(3) The critical chloride concentration scope of SCC in high hardness circulating cooling water was 710mg/L-1000mg/L, once the chloride was higher than 1000mg/L SCC occurred. The water treatment agent Rp-04L has marked improvement on critical value-about 2000mg/L.(4) The effect of strain and chloride concentration on pitting corrosion can be detected by in-situ electrochemical tests under constant strain, contrasting with the results from slow strain rate tests, the new in-situ electrochemical tests could pilot study the critical condition of SCC.
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