Issue 27

H. Liu et alii, Frattura ed Integrità Strutturale, 27 (2014) 53-65 ; DOI: 10.3221/IGF-ESIS.27.07 64 2. The SEM microstructures of the fracture surfaces revealed that clear characteristics of a brittle fracture can be observed. Such characteristics were transgranular and intergranular cleavage fracture, pores, secondary cracks, and carbon- deficient phase. The metallographic analysis results revealed that the presence of a specific amount of eta-phase can increase material brittleness. The processing defects of the WEDM cutting method were observed under SEM. Many voids, pores, and microcracks were found on the cutting surfaces at the vicinity of the fracture locations. These defects can reduce material strength and cause total failure. 3. The results of numerical simulations and experimental tests indicated that the baseplate fracture accident was the brittle fracture failure with low stress. Fracture failure was attributed to the manufacturing defects in WC-11Co cemented carbide sintering and the processing defects of the WEDM cutting method. R EFERENCES [1] Han, G., Bruno, M., Lao, K.H., Percussion drilling in oil industry: review and rock failure modeling, The AADE national technical conference and exhibition, April 5-7, Houston, USA, (2005). [2] Wanamaker, J.A., Rotary percussion drilling in West Texas, World Oil, (1951) 182-187. [3] Melamed, Y., Kiselev, A., Gelfgat, M., Dreesen, D., Blacic, J., Hydraulic hammer drilling technology: developments and capabilities, J. Energ. Resour. Technol., 122(1) (2000) 1-8. [4] Yin, K., Wang, M.S., Peng, J.M., Wang, R.S., Percussive-Rotary Drilling, Geological Publishing House, Beijing, (2010) 88-112. [5] Wang, R.J., Jiang, R.Q., Han, J.Z., Liquid-Driven Percussive-Rotary Drilling, Geological Publishing House, Beijing, (1988) 97-104. [6] Wang, D., Zhang, W., Zhang, X.X., Drilling Techniques for China Continental Scientific Drilling Engineering No.1 Well, Science Press, Beijing, (2007). [7] Piao, C.Z., Yin, K., Jiang, R.Q., Wang, M.S., Experimental research on application of KSC-127 fluid efflux hammer in CSDP,. World Geol., 19(3) (2000) 295-298. [8] Wang L., Wang W.G., Dou T.W., Xu L.H., Wang X.Y., Application of rotary percussion drilling technology in reverse thrust nappe structure formation, Oil Drill & Production Technol., 27(sup) (2005) 8-10. [9] Wen, P., Chen, B., Lei, J.P., Yan, Y.C., Application of hydraulically impacting-rotary drilling technique in qingxi area of Yumen oil field, Nat. Gas Ind., 24(9) (2004) 64-67. [10] Xiong, Q.S., Huang, Z.Q., Yin, K., Tian, H., Experimental research on a new type of hydro-efflux hammer in drilling deep and ultradeep wells, Nat. Gas. Ind., 28(12) (2008) 65-67. [11] Shen, J.Z., He, Q., The application of model YSC-178 hydraulic jet hammer in rotary percussion drilling, China Petrol. Mach., 39(6) (2011) 52-54. [12] Reisch, U., Meuer, R., CFD-simulation of the flow through a fluidic amplifier, Sensor Actuator A: Phys., 43(1-3) (1994) 330-334. [13] Peng, J.M., Liu, H., Zhao, Z.Q., Bo, K., Wang, W., Erosion mechanism on outer wall of bottom plate of fluidic amplifier for YSC178A liquid jet hammer, J. Jilin Univ.-Earth Sci., 40(5), (2010) 1140-1144. [14] Li, W.T., The Experiment and Research on the Working Life of the Liquid Jet Amplifier of the Hydraulic Hammer, M.E. Thesis of Jilin University, (2004) 20-50. [15] ANSYS LS-DYNA User’s Guide. Version 10.0, (2010). [16] Chen, J.W., Research on Simulation and Experiment of Liquid Jet Hammer, Ph.D. Thesis of Jilin University, (2007) 39-113. [17] Chen, J.W., Yin, K., Peng, J.M., Gu, L.Y., Zhou, B., Numerical simulation of the performance of the SC-89 jet impact system, Proceedings of the ASME dynamic systems and control conference-PTS A and B, (2010) 913-920. [18] Li, G.L., Peng, J.M., Liu, H., Zhao, Z.Q., Prediction and verification of threshold flow velocity for jet nozzle of hammer hydro, J. Jilin Univ.-Earth Sci. 40(1) (2005) 159-163. [19] Fluent User's Guide, Release 6.3.26, Ansys Inc. USA, (2006). [20] Khelfaoui, R., Colin, S., Caen, R., Orieux, S., Baldas, L., Numerical and experimental analysis of monostable mini- and micro-oscillators, Heat Transfer Eng. 30 (1–2) (2009) 121–129. [21] Wang, F.J., The Analysis of Computational Fluid Dynamics: CFD Software Principle and Application, Tsinghua University Press, Beijing, (2004). [22] Specification for Threading and Gauging of Rotary Shouldered Thread Connections, API specification 7-2/ISO 10424-2, (2008) 67-79.