HIGH-TEMPERATURE HYDROGEN ATTACK (HTHA) of steels is an extremely interesting topic in petrochemical industrial applications, while a predictive physical model still does not exist. A number of studies carried out in the world are unambiguous confirmation of that statement. Bearing in mind multiple effects of hydrogen in certain metals, the specific mechanism of high-temperature hydrogen attack embrittlement is shown, depending on the experimental conditions.

The susceptibility of ASTM1 204 Gr A steel to hydrogen-assisted cracking was evaluated using a mechanical fracture test on samples of the analyzed refinery Reactor-A. Samples were loaded in tension and subjected to impact mechanical testing to evaluate the probability of occurrence of the hydrogen-assisted cracking phenomenon. Fractography, Nondestructive testing (NDT), and scanning electron microscope (SEM) analysis carried out on the fracture surfaces of the ruptured beams revealed that there was no evidence of the mechanisms of the crack propagation. Under both conditions, the indication was lamination, with incipient plastic deformation. The results did not show the influence of hydrogen-induced embrittlement on the initiation of the indication. From the observations, a lamination process is proposed. Also, the fracture toughness of the samples was evaluated by linear elastic fracture mechanics and the validity of the results is discussed. This result was very important for the Barrancabermeja refinery to develop inspections plans and make sound operations decisions based on the best available techniques.

Subject
High temperature hydrogen attack, External surfaces, Materials, Reactors, Surface hardness, Inspection, Metallography, Defects, Internal surfaces, Equipment, Damage, Inclusions, Samples
Keywords:
Carbon Steel, Small Punch, High Temperature Hydrogen Attack (HTHA)
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2019
Association for Materials Protection and Performance (AMPP)
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