해양 환경 하에서 431 스테인리스강의 하이브리드 실험을 통한캐비테이션 손상 거동

The demand for stainless steel is continuously increasing with the development in offshore industry dueto its excellent corrosion resistance characteristics. However, it suffers cavitation-erosion in application ofhigh rotating fluid and the damage accelerates in combination with electrochemical corrosion because of Clionin sea water. This paper investigated the complex damage behavior for 431 stainless steel, that is oneof martensite stainless steels, through the hybrid test in sea water. Various experiments were carried out,including potential measurement, anodic/cathodic polarization experiment and Tafel analysis. Surface morphologywas observed and damage depth was analyzed by SEM and 3D microscope after each experiment,respectively. The results revealed that more active potential was observed under cavitation condition thanstatic condition due to breakdown of passive film and activation of charge transfer, and that higher corrosioncurrent density was obtained under cavitation condition due to synergistic effect of corrosion and erosion. The demand for stainless steel is continuously increasing with the development in offshore industry due to its excellent corrosion resistance characteristics. However, it suffers cavitation-erosion in application of high rotating fluid and the damage accelerates in combination with electrochemical corrosion because of Cl- ion in sea water. This paper investigated the complex damage behavior for 431 stainless steel, that is one of martensite stainless steels, through the hybrid test in sea water. Various experiments were carried out, including potential measurement, anodic/cathodic polarization experiment and Tafel analysis. Surface morphology was observed and damage depth was analyzed by SEM and 3D microscope after each experiment, respectively. The results revealed that more active potential was observed under cavitation condition than static condition due to breakdown of passive film and activation of charge transfer, and that higher corrosion current density was obtained under cavitation condition due to synergistic effect of corrosion and erosion. KCI Citation Count: 1