Magnetic Memory Testing Towards Fatigue Damage For Remanufacturing Of Ferromagnetic Components

The remanufacturing detection is the key point in remanufacturing engineering system, and determines whether products could be remanufactured. Metal magnetic memory (MMM) is a new non-destructive testing technique, which can be used for early identification of defect for components. All kinds of service components are often subjected to the stretching and bending fatigue loading in the industrial production, such as engine connecting rods, axle housings, bearing beam. Fatigue damage has become the main form of product damage. It is of great significance to promote the development of manufacturing engineering by research MMM testing of fatigue damage for ferromagnetic component. The main content of this paper include the following aspects:(1) Aimed at the remanufactured components, the typical ferromagnetic material510L steel and Q345steel are selected as the object, fatigue damage process under tensile load are simulated, and the features of magnetic memory signal are studied. The relationship between stress intensity factor KI, stress concentration factor K,, crack length L, fatigue cycle times N, load etc, and magnetic memory signal component Hp(y), gradient value of K is analyzed. The quantified relationship between characteristics of magnetic memory signal and the factors is expounded based on the theory of ferromagnetic material magneto-mechanical effects and fatigue fracture. It’s found that magnetic memory testing can be applied to damage detection of tensile fatigue.(2) The three-point bending specimens of SE(B) with a gap are selected, the crack propagation are studied in the process of fatigue loading, magnetic memory signals are described under bending load, and the joint detection method of diffraction slit width and magnetic memory technology is discussed by combining with X-ray diffraction. It showed that stress concentration and plastic deformation are set as the patterns of early damage by means of the X-ray diffraction slit width and magnetic memory signals respectively, which identifies that the proposed joint detection method is reliable.(3) It takes automobile drive axle housing as the non-destructive testing object for remanufacturing. Magnetic memory technology is applied as the primary detection method to achieve the rapid detection of axle housing, non-destructive testing method and system for automotive drive axle housing are established, and then a versatile method is provided for non-destructive testing of remanufactured components.