Hydrogen trapping sites in a submerged arc welding (SAW) weld metal were investigated using tritium autoradiography. Diffusible tritium was able to escape from the present specimens within 72 h, and transmission electron microscope (TEM) observation of thin foil specimens that were kept at room temperature for 72 h before tritium autoradiography showed that dislo cations were the main trapping sites. No evidence was found to indicate that oxides or carbides behaved as trapping sites, but further investigations into this are needed. The present experimental procedure is expected to provide a powerful method for analysis of hydrogen trapping sites in weld metal.
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References
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