Stress Corrosion Experimental Research Of 304 Austenitic Stainless Steel In H₂S+Cl^-+CO₂+H₂O Complex Medium Condition

Given the situation that corrosion resistant alloy's corrosion mechanism in complex medium environment is not clear yet,related design work is in lack of sufficient reference data as well.This paper choses 304 austenitic stainless steel as the research subject,which is widely used in the petrochemical industry.A series of research work is conducted to explore 304 austenitic stainless steel's SCC failure problem in H₂S+Cl^-+CO₂+H₂O acid corrosive medium environment.The major research works and academic achievements are as follows.?1?By means of SSRT experiment and SEM&EDS analysis,the connection between medium parameter change and the SCC susceptibility indexes of 304 austenitic stainless steel in H₂S+Cl^-+CO₂+H₂O acid corrosive environment is established.The medium environment that 304 austenitic stainless steel shows highest SCC susceptibility is screened out as well.The result displays that 304 austenitic stainless steel shows higher stress corrosion sensitivity in H₂S+Cl^-+CO₂+H₂O complex medium environments than in mono-medium environments.Among all the test medium environments,304 austenitic stainless steel shows highest SCC susceptibility in 3.5% NaCl solution with H₂S and CO₂ saturated.?2?Through WOL experiment,the SCC crack growth pattern of 304 austenitic stainless steel in H₂S+Cl^-+CO₂+H₂O acid corrosive environments is figured out.The result shows that 304 austenitic stainless steel is more susceptible to conceive SCC crack and its crack propagation rate in 3.5% NaCl solution with CO₂ and H₂S saturated is faster than those in 5% NaCl solution with CO₂ and H₂S saturated,too.?3?Based on the stepwise regression analysis result of SSRT experiment statistics,the interaction math model of test medium parameters and SCC susceptibility index is established.The fitting result indicate that the concentration of H₂S,Cl^-and CO₂ are the crucial influencing factors and they may interact with each other in the process of 304 austenitic stainless steel's stress corrosion.The significance order of test mediums' influence on 304 austenitic stainless steel's stress corrosion is Cl^->H₂S+Cl^->CO₂>CO₂+H₂S>H₂S>Cl^-+CO₂.This paper systematacially carried out relevant research work concering 304 austenitic stainless steel's stress corrosion in H₂S+Cl^-+CO₂+H₂O acid corrosive medium environment.Its research results can provide reference for relevant research or basis for the safety evaluation of process equipments and pipelines.