The detection of tritium and14C-ethylene on the surface of nickel sheet was carried out by means of autoradiography. Two autoradiographical methods were
used, the ordinary stripping-film method and the electron-microscope autoradiographical method. The ordinary autoradiographs
indicated that14C-ethylene accumulates at scratches on the surface of the sheet; however, tritium accumulates at grain boundaries and scratches.
Electron-microscope autoradiographs indicated that tritium accumulates on the step-edges of slip band of nickel.