13th International Conference on Fracture June 16–21, 2013, Beijing, China -8- for the material 410S. In Fig. 9, four data points from the in-phase TMF tests with temperature cycling between 100 and 480°C are provided. It is found that the fatigue life of 410S under TMF loading is even shorter than the life at constant temperature of 480°C, though in the TMF loading the maximum temperature is 480°C. Due to the insufficient amount of data conducted, more data points are required to verify the trend of this observation. 4. Summary In this paper, newly-developed thermal-mechanical fatigue testing system is presented. The developed system can successfully simulate in-phase thermal-mechanical loading which is similar to the loading experienced by the coke drums. Some key developments of this system are introduced such as heating device and control system. In addition, an alternative strain control and measurement technique was developed for both isothermal and TMF fatigue tests Furthermore, some preliminary fatigue tests results were presented. For isothermal fatigue tests, it is shown that as temperature increases, the fatigue lives of SA387 and 410S decrease significantly. Additionally, by comparing lives between isothermal and thermal-mechanical fatigue, it is found that the fatigue life of 410S under TMF loading is shorter than the life at 480°C. Therefore, it is inaccurate to estimate the service life of coke drums based on isothermal fatigue data. Due to the insufficient amount of experimental data, this trend need to be further verified and the mechanisms of this observation need to be explored. More tests are still carrying on in our lab. Based on the comprehensive experimental investigation, reasonable fatigue life models will be developed for the coke drum materials. Acknowledgements This research is supported by a Collaborative Research and Development (CRD) Grants of The National Science and Engineering Research Council (NSERC) of Canada (CRD #350634-07 and CRDPJ 403054-10). References [1] Penso, J. A., Lattarulo, Y. M., Seijas, A. J., Torres, J., Howden, D., and Tsai, C. L., 1999, “Understanding Failure Mechanisms to Improve Reliability of Coke Drum,” ASME, New York, PVP-Vol. 395, pp. 243–253. [2] Ramos, A., Rios, C., Vargas, J., Tahara, T., and Hasegawa, T., 1997, “Mechanical Integrity Evaluation of Delayed Coke Drums,” Fitness for Adverse Environments in Petroleum and Power Equipment, ASME, New York, Vol. 359, pp.291–298. [3] Ramos, A., Rios, C., Johnsen, E., Gonzalez, M., and Vargas, J., 1998, “Delayed Coke Drum Assessment Using Field Measurements and FEA,” Analysis and Design of Composite, Process, and Power Piping and Vessels, ASME, New York, Vol. 368, pp. 231–237. [4] Ramos, A. J., Rios, C. and Vargas, J.A.R., 1999, “Fatigue Life Prediction of Delayed Coke Drums”, Vision Techenologica, Vol.6, pp. 93-100 [5] Z. Xia, F. Ju, and P. D. Plessis, 2010, Heat Transfer and Stress Analysis of Coke Drum for a Complete Operating Cycle, Journal of Pressure vessel technology, 132.
RkJQdWJsaXNoZXIy MjM0NDE=