Evaluation Of Remaining Corrosion Fatigue Life For High-pressure Hydrogenation Cracking Reactor

Fatigue failure is the main failure mode for the hydrogenation reactor that not only works under the high temperature, high pressure and alternation loading condition over a long period of time, but also works under the bad environment that is filled of the Hydrogen . One kind of fatigue failure that often appears is corrosion fatigue. The fatigue of structure is such a complicated phenomenon affected by many uncertainties that it is necessary to analyze the structural fatigue from the point of probability and statistics. As a branch of fracture mechanics, the various parameters affecting the fatigue propagation are considered as randomized. It is an effective and new method to evaluate the structural fatigue reliability by Probabilistic Fracture Mechanics Approach.Firstly, the paper is aimed at the characteristic of hydrogenation reactors made of 2.25 Cr-Mo steel, and analysis the common defect that include hydrogen attack, temper embrittlement, stress cracking, weld overlay removal and so on. The paper draw up the different fault tree for different defect, and provide the basis theory of safe using and science detecting to the reactorThen, the object of the present paper was to study the relationship between corrosion fatigue crack growth rate da/dN and stress intensity factor amplitudeâ–³K of 2.25Cr-Mo steel by corrosion fatigue crack growth rate experiment in Hydrogen solution. This steel is the typical material used in chemistry and oil chemistry equipment. Corrosion fatigue safety assessment method of hydrogenation reactor with defects in service could be explored and investigated.Finally, Monte-Carlo method is used to predict corrosion fatigue crack growth rate and remainder life. And the influences of the random parameters on corrosion fatigue propagation are discussed. The paper give the corrosion fatigue crack growth rate of 2.25Cr-Mo steel under the different hydrogen pressure and temperature. The paper give a new stochastic crack propagation model using Monte-Carlo method, numerical examples are shown, the results review the developed method is applicable.