Influence of an electric charge during quench aging of a low-carbon steel

Abstract

We report here the first investigation on the quench aging of a low-carbon steel under the influence of an electric charge produced by 6.7 kV dc voltage between the specimen and a parallel electrode separated by 5 mm. This arrangement produced the following effects: (a) retarded the aging kinetics and (b) reduced the peak hardness. Fitting the results to a thermally activated rate equation indicated that the activation energy was increased from 0.65 to 0.85 eV. TEM observations revealed significant changes in precipitate size, morphology, and distribution near the grain boundaries and in the grain interior. It is proposed that the existing electrical conditions enhanced the migration of quenched-in vacancies from the grain interior to the grain boundaries.