THE EFFECT OF ANODIC POLARIZATION ON THE AMBIENT CREEP OF BRASS

The effect of anodic and cathodic polarizations on the ambient creep o f brass in 3.5% NaCl and CH3COOH + CH3COONa solutions has been investi gated. The results showed that the creep rate in both solutions increa sed linearly with the increase of the anodic current density and was a pproximately inversely proportional to the square of the radius of the specimen. The depsilon/dt in 3.5% NaCl solution was much higher than that in the CH3COOH + CH3COONa solution at the same anodic current den sity. The creep rate resulting from dislocation climb induced by vacan cy supersaturation during the anodic polarization has been calculated as follows: depsilon/dt = K betai/r2 where K = 8pialphaMrhoD(s)DELTAtD ELTAr/C0dFZln (R/b), and beta is a constant related to the degree of d e-alloying. The experimental data support the proposed mechanism. Cath odic polarization could also increase the ambient creep of brass by a mechanism related to hydrogen-facilitated local plastic deformation.