Abstract
Multiple in-service fractures of torsion springs were experienced in the same system, which was the support assembly to the electrical pickup for an electric-powered vehicle, similar to a subway rail car or electric trolley car. Scanning electron microscopy and metallographic examinations determined that the fractures initiated due to electric arc damage. Intergranular quench cracks at the spring surface through the transformed untempered martensite provided crack initiations for fatigue that propagated during operation.
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J.R. Davis (ed.), ASM Metals Handbook Volume 12: Fractography (ASM International, Materials Park, 1987), pp. 280–281
J. Shigley, Mechanical Engineering Design, 3rd edn. (McGraw-Hill, New York, 1977), p. 298
J. Landes, W.T. Becker, R. Shipley, J. Raphael, “Stress analysis and fracture mechanics,” in ASM Handbook Volume 11: Failure Analysis and Prevention (ASM International, Materials Park, 2002), p. 472
G.E. Totten, M. Narazaki, R.R. Blackwood, “Failures related to heat treating operations,” in ASM Handbook Volume 11: Failure Analysis and Prevention (ASM International, Materials Park, 2002), p. 208
W.T. Becker, S. Lampman, “Fracture appearance and mechanisms of deformation and fracture,” ASM Handbook Volume 11: Failure Analysis and Prevention (ASM International, Materials Park, 2002), pp. 578–579
J.R. Davis (ed.), ASM Metals Handbook Volume 12: Fractography (ASM International, Materials Park, 1987), pp. 3, 224, 281, 335
T. Gross, “Micromechanisms of monotonic and cyclic crack growth,” in ASM Handbook Volume 19: Fatigue and Fracture (ASM International, Materials Park, 1996), p. 49
P. Lukas, “Fatigue crack nucleation and microstructure,” in ASM Handbook Volume 19: Fatigue and Fracture (ASM International, Materials Park, 1996), p. 96
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Maciejewski, J., Akyuz, B. Spring Fatigue Fractures Due to Microstructural Changes in Service. J Fail. Anal. and Preven. 14, 148–151 (2014). https://doi.org/10.1007/s11668-014-9783-9
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DOI: https://doi.org/10.1007/s11668-014-9783-9