Study on failure evolution of 15CrMo steel used for aviation kerosene hydrogenation unit

Abstract

In aviation kerosene hydrogenation unit, the 15CrMo steel with good resistance to hydrogen embrittlement performed obvious pitting corrosion with certain micro-cracks in H2/H2S environment. In this paper, the failure behavior of 15CrMo steel in H2/H2S environment had been studied using electrochemical method and microscopic morphology. The results showed that within 10 days, the 15CrMo steel performed good resistance with a smaller max pit depth (15.48 μm on the 10th day) in H2/H2S environment, proved by the passivation zone (−0.75 ∼ −0.62 V on 10th day). Furthermore, 15CrMo steel exhibited activated corrosion with a significantly increasing max pit depth and corrosion current density, especially, reaching 131.91 μm and 17.29 μA m−2 on 30th day. Moreover, the stress corrosion cracking caused by H2S appeared on 30th day.