Failure Investigation of Hydrogen Blistering on Low-strength Carbon Steel

The current study assesses the root causes of hydrogen blisters on low strength carbon steelequipment. For this purpose, some experiments including hardness test, non-destructive test (NDT),metallography, and fractograpghy are conducted. The microstructure of two blisters is assessed bymeans of optical microscopy and scanning electron microscopy (SEM). The microstructural studiesshow that the steel plate has some inclusions and banded ferrite/pearlite structure. The energydispersive x-ray spectroscopy (EDS) results indicate that these inclusions mainly contain Mn, S, Al,Ca, and Si. The results show that the inclusions and planar imperfections found in the NDT havebeen the nucleation locations for blisters in the plate. Remediation action plans are recommended toprevent further occurrence and growth of hydrogen blisters.

کلیدواژه ها:

Low-strength Carbon Steel ، Hydrogen Blister ، Storage Tank ، Imperfection