Affiliations: [a] School of Mechanical Science and Engineering,
Northeast Petroleum University, Daqing, Heilongjiang, China | [b] Data Interpretation and Evaluation Center, No.1 Mud
Logging Company, Daqing Drilling and Exploration Engineering Corporation,
Daqing, Heilongjiang, China | [c] Daqing Medical College, Daqing, Heilongjiang,
China
Correspondence:
[*]
Corresponding author: Jiancheng Leng, School of Mechanical
Science and Engineering, Northeast Petroleum University, Daqing 163318,
Heilongjiang, China. Tel.: +86 459 650 3884; E-mail: [email protected]
Abstract: A newly arisen technique named metal magnetic memory is deemed to
have potentials in detecting early damage, whereas it is lack of systematic
micro-mechanism research in early fatigue damage of ferromagnetic components.
The microscopic fatigue experimental system including XH-500 metallograhpic
microscope, DIG300 special digital camera and magnetic memory testing device,
combined with the magnetic memory microscopic fatigue observation method is
adopted, and the tension-tension fatigue experiment with specimens made of
steel 45 are conducted. The evolution process of fatigue short-crack initiation
and growth is observed dynamically from the microscopic scale, and the
variation regularity of microscopic Vickers hardness during the fatigue
procedure is also given. At the same time, the variation of the magnetic memory
signal on the surface of the V-shaped notch with cyclic numbers is analyzed,
and the magnetic signal curve distribution regularity corresponding to
different crack lengths is investigated. The results show that the magnetic
memory signals exhibit an abnormal nonlinear wave when the local plastic
deformation or micro-damage occurs, providing a feasible detection method for
early fatigue damage of ferromagnetic materials.
Keywords: Metal magnetic memory, early fatigue damage, crack initiation and propagation, signal characteristics
