Observations of hydrogen trapping sites In submerged are weld metal using tritium autoradiography

Hydrogen trapping sites in a submerged are welding (SAW) weld metal were in vestigated using tritium autoradiography. Diffusible tritium was able to es cape from the present specimens within 72 h, and trans mission electron mic roscope (TEM) observation of thin foil specimens that were kept at room tem perature for 72 h before tritium autoradiography showed that dislocations w ere the main trapping sites. No evidence teas found to indicate that oxides or carbides behaved as trapping sites, brit further investigations into th is are needed. The present experimental procedure is expected to provide a powerful method for analysis of hydrogen trapping sites in weld metal.