EFFECT OF CRYSTALLIZATION ON THE STOCHASTIC PIT GENERATION PROCESS OFFE-CR-SI-B AMORPHOUS ALLOY

The effect of crystallization on the stochastic pit generation process of an Fe-Cr-Si-B amorphous alloy in a berate solution containing Cl- ions has been analyzed. Fitting potential of amorphous alloys showed a wide scatter and mean value shifts to the noble direction before crys tallization starts, decreasing rapidly after crystallization, Stochast ic analysis demonstrates that the initial increase in pitting potentia l is brought about by an increase in the pit repassivation rate, while the decrease in pitting potential after crystallization is caused by a rapid increase in the pit generation rate. Silicon oxide film format ion during the heat treatment is concluded to be the main reason to in crease the pitting potential and alpha-Fe micro-crystallites by crysta llization in the latter stage of the heat treatment are responsible to decrease the pitting potential.