Application of high resolution autoradiography to study the microsegregation of carbon in thin foil microstructures of a 12% Cr steel using ¹⁴C as a radioactive tracer

Abstract

The technique of high resolution microautoradiography has already been applied to study the microsegregation of carbon and tritium in iron and its alloys, but autoradiographs have so far been obtained using liquid nuclear emulsions and carbon replicas on massive specimens. This technique has now been extended to study the distribution of carbon in thin foil microstructures of a 12% chromium steel in the quenched and tempered condition. An experimental procedure has been developed for obtaining autoradiographs on thin foils, and is described in detail. The limitations of the technique with respect to efficiency and resolution have been considered. The results obtained show that high resolution microautoradiography on thin foils permits a more precise localization of the radioactive tracer atoms with respect to the microstructural features and gives a better resolution, even with a radioisotope emitting high energy β particles, in comparison with the replica method on massive specimens.