| Coke tower is the core equipment coke process and use one of the worst equipment environment in multiphase environment, long-term experience severe pressure circulation and thermal circulation, can produce weld cracking and cylinder tower festival bouffant deformation. In order to establish to ratchet effect on comparatively accurate structure and comprehensive estimate of constitutive model, it is necessary to materials in different temperature cyclic plastic behavior of in-depth system.Experimental mother materials at home and abroad material selection of coke tower typical material 1.25Cr0.5Mo alloy steel, Through the MTS 810 electro-hydraulic servo tester materials in 20℃, 200℃, 300℃and 480℃temperature conditions such as a series of uniaxial cyclic ratchet experiment. Test results show that: 1.25Cr0.5Mo alloy steel is a kind of circulation stabilization materials, and is the rate-independent; Weld and heat affected zone metal exhibited weak circulation weakening behavior, but overall as circulation stabilization. Uniaxial cyclic ratchet effect in experiments, with the increase of average stress, peak stress and stress amplitude, ratchet strain increases; Ratchet deformation is dependent upon loading history, previously large cyclic stress on subsequent smaller cyclic stress deformation under ratchet up the inhibition.According to the tensile experiments and ratchet experiment data further identified Chaboche model, O- W model and double linear servo improved model (BKH) finite element analysis model of model parameters, O - W II model can of material uniaxial ratchet strain preferable forecasting. Using the self-designed mobile temperature loading devices in resistance strain gauge, experiment on the temperature of axial movement under the action of weld cylinder with rings are tentative circulation ratchet effect experimental research, and put forward some reasonable suggestion for improvement. |
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