NaCl水溶液中1CrNi9Ti钢的缝隙腐蚀

CERVICE CORROSTON OF 1Cr18Ni9Ti STEEL IN AQUEOUS NaCl SOLYTON

研究了1Crl8Ni9Ti钢在0.03％、0.3％、及3％NaCl水溶液中金属/金属缝隙蚀的萌发、成长和再钝化。结果表明:(1)缝隙腐蚀存在一个临界电位V_(CREV);若负于此电位,缝隙腐蚀虽可能发生,但不久便再钝化。缝隙腐蚀的再钝化电位E_R,是缝隙构造的特征值,其下限值与V_(CREV)相一致;(2)缝隙腐蚀的发生具有概率性,各条件下有一稳定的发生率,它是独立于E_(EREV)的缝隙腐蚀的另一特征值;(3)缝隙腐蚀的发展随温度、电位的升高而加快,并遵循不同的规律。

The initiation, growth, and repassivation of metal/metal crevice corrosion of lCr18NigTi steel in aqueous 0.03%, 0.3%and 3%NaCl solutions were investigated. Laboratory date indicate: (1) There exists a critical potential V_(CREV) for crevice corrosion. When a specimen is polarized to a potential more positive than V_(CREV), crevice corrosion is likely to grow. When polarized to a value more negative than V_(CREV), crevice corrosion can still occur but the specimen soon becomes repassivated. The repassivation potential of the specimen E_R, is a characteristic value depending on the geometry of the crevice configuration. The lower limit of E_R coincides with that of V_(CREV), (2) The initiation of crevice corrosion follows probability statistics. The initiation probability is found to have a stable value under specified conditions. This probability is another characteristic of crevice corrosion and is independcnd of E_R, (3)The growth (development) of crevice corrosion becomes accelerated with rise in temperature and potential but in different ways.