A linear display defect was found in the heat exchange tube during PT test after the heat exchanger was manufactured of an equipment manufacturer.The defects of TP316L stainless steel heat exchange tube was analyzed by direct-reading spectrometer,optical microscope metallographic analysis,non-metallic inclusion analysis,intergranular corrosion test analysis,SEM analysis.The results showed that the defects were folded during cold rolling during the production of steel tube,and expanded after threading,expanding and welding during subsequent heat exchanger manufacturing.A linear display appears when PT is detected.This conclusion provides a powerful reference for the product quality assurance of industrial mass production of metal tube products.
维普
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