Babiy L. Estimation of high temperature hydrogen degradation of heat resistant steel of oil hydrocracking reactors

High temperature hydrogen degradation of hull plates of hydrocracking reactors in-laboratory and in-service conditions. Goal of the work - to investigate structural changes and mechanical properties of structural steels of hull plates of hydrocracking reactors after degradation under long-term influence of high-temperature hydrogenated environment in-service and in-laboratory conditions. Investigation methods: metallographic analysis, electron microscopy, simulating of metal degradation in-laboratory conditions, mechanical testing. Results - there is shown that degradation of hull plates under combined influence of high temperature and hydrogenating environment becomes apparent on microstructure level by carbides redistribution. Hydrogen is revealed to increase a steady creep rate of structural steel of a reactor not depending on degradation level, and steady creep rate of the 2,25Cr-1Mo steel is increasing as result of metal degradation in-service conditions too. Distinctions between fracture mechanisms for degraded and undegraded steel under hydrogen influence were developed. The necessity of taking into account changing regularities of creep properties of heat-resistant steels under influence of degradation and hydrogen during technical state of exploited metal was substantiated. Results of this dissertation have been used on Nadvirna refinery of JSC "Naftohimik Prykarpattya", field - refinery industry.