Experimental Investigation of Hydrogen Effect on Mechanical Properties of 304L Stainless Steel

Hydrogenation reactor is one of the key equipments in the production process of purified terephthalic acid (PTA). The safe and reliable operation of hydrogenation reactor decides the safety of PTA installation. Service experience has shown that some longitudinal cracks occurred on the internal wall of the 304L stainless steel (SS) hydrogen nozzle. In this paper, a series of electrochemical hydrogen charging tests were carried out for 304L stainless steel at the ambient temperature. The comparison on mechanical properties was investigated before and after hydrogen charging in order to investigate the effect of mechanical properties of 304L SS. Fractography was analyzed by using scanning electron microscope (SEM). The results showed that the mechanical strength of 304L SS was not basically lost after hydrogen charging, but the ductility reduced in a certain extent. The fractography also showed the hydrogen embrittlement effect on the fracture.