A large number of punctate defects were found in a welded joint of a medium and heavy plate spherical tank by ultrasonic time of flight diffraction technique(TOFD).After the welding cause was excluded,an analysis of low-magnification detection and metallographic inspection was conducted using sampling techniques.This revealed that the defects found by TOFD were related to the presence of MnS inclusions in the base metal and nitride inclusions containing Nb and Ti in the aggregate state.The high number of inclusions had a direct impact on the quality of the welding.Verification of the location of defects through adjustment of the scanning method provides a basis for the identification and assessment of defects detected by TOFD.
关键词
球罐/衍射时差法超声检测/夹杂物/缺陷/判别
Key words
spherical tank/ultrasonic time of flight diffraction technique/inclusion/defect/identification
维普
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