Effect of microstructure on non-linear behavior of ultrasound during low cycle fatigue of pearlitic steels

▶ Development of online NLU parameter determination system with proper calibration. ▶ Correlation of microstructural changes with the variation of NLU parameter during low cycle fatigue in 0.3 wt.% carbon steel. ▶ NLU parameter follows fatigue hardening and softening trends during low cycle fatigue in test material. ▶ Before failure, fracture of cementite plates due to compressive stress causes a sharp increase in NLU parameter that could be the alarm for failure of components. Hence this technique may prevent catastrophic failure of components.