Study on Characteristics of Magnetoacoustic Emission for Q235 Steel Subject to Fatigue Process

Fatigue fracture is one of the failure modes in the ferromagnetic metal material. The suddenness of the fracture often causes the catastrophic accident Therefore, in order to prevent the fatigue failure of metal materials, the detection and evaluation of the early fatigue state of metal materials are very important. However, the traditional nondestructive testing (NDT) methods are not suitable for the rapid detection of early fatigue conditions of metal materials. Therefore some advanced NDT methods need to be proposed. Magnetoacoustic emission (MAE) is a great potential NDT method in early fatigue testing of ferromagnetic metal materials, because MAE is sensitive to the microstructure and stress state of materials. Therefore, in this paper, the low cycle fatigue of Q235 steel is analyzed by finite element simulation. The life of Q235 steel is also predicted according to Smith-Watson-Topper(SWT) model. Finally, the MAE characteristics of low cycle fatigue in Q235 steel is given.