关键词: Fe_Cr_Ni合金(800M), 稳态溶解电流密度, 极化溶解敏感指数, 碱性SCC, 电化学预测

Abstract: Stress corrosion cracking (SCC) of Fe_Cr_Ni alloy (alloy 800 M) in hot concentrated caustic solution was investigated by means of tests of C_rings under controlled potentials. The steady dissolution current densities( i st ) of the plate specimens and C_rings polarized potentiostatically were measured. The simplifed steady potentiostatical curves were drawn on the basis of i st . The ratio R PD measured from i st and steady passive current density i p at low potentials ( R PD = i st / i p ) was designed as a polarization dissolution susceptibility parameter. The parameter R PD values of both plate and C_ring specimens were similar to SCC sensetive potentials of C_rings between-30 mV/SCE and 40 mV/SCE. An Electrochemical prediction method for caustic SCC was proposed basd on the electrochemical characters synthesizing i st and R PD .