| Title |
Measurements of Resistance to Pitting and Crevice Corrosion of Stainless Steels Using Electrochemical Methods |
| Authors |
이재봉(Jae Bong Lee); 민심근(Sim Kun Min) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
pitting corrosion; crevice corrosion; critical pitting temperature; CPT; critical crevice temperature; CCT; critical crevice potential; CCP; PREN; capacitance; repassivation |
| Abstract |
The resistance to pitting and crevice corrosion of various stainless steels was evaluated by measuring critical pitting temperature (CPT), critical crevice temperature (CCT) and critical crevice potential (CCP). CPT values obtained from immersion test were compared with those done by electrochemical test methods. The relationship between CPT and CCT was investigated in terms of PREN (pitting resistance equivalent index). The effect of types of crevice formers on CCT was examined. CCP values for different stainless steels were measured and compared with their CCT values. The properties of passive film obtained by capacitance and abrading electrode measurements were compared with the resistance to corrosion. Results show that CCP and CCT increased with increasing PREN, indicating the linear relationship between CPT and CCT values. Independent of types of crevice former such as block or washer, CCT showed the same values in both cases. The correlation between CCT and CCP showed that CCT linearly increased with increasing PREN while CCP increased up to 40 of PREN, approached the constant values above 40. The higher PREN values resulted in the lower donor density and the closer repassivation rate parameter to 1. |