Metal magnetic memory field characterization at early fatigue damage based on modified Jiles-Atherton model

Abstract

In order to propel the development of metal magnetic memory (MMM) technique in fatigue damage detection, the Jiles-Atherton model (J-A model) was modified to describe MMM mechanism in elastic stress stage. A series of rotating bending fatigue experiments were conducted to study the stress-magnetization relationship and verify the correctness of modified J-A model. In MMM detection, the magnetization of material irreversibly approaches to the local equilibrium state M₀ instead of global equilibrium state M_an under cyclic stress, and the M₀−σ curves are loops around the M_an−σ curve. The modified J-A model is constructed by replacing M_an in J-A model with M₀, and it can describe the magnetomechanical effect well at low external magnetic field. In the rotating bending fatigue experiments, the MMM field distribution in normal direction around cylinder specimen is similar to the stress distribution, and the calculation result of model coincides with experiment result after some necessary modifications. The MMM field variation with time at a certain point in fatigue process is divided into three stages with the variation of stable stress-stain hysteresis loop, and the calculation results of model can explain not only the three stages of MMM field changes, but also the different change laws when the applied magnetic field and initial magnetic field are different. The MMM field distribution in normal direction along specimen axis reflects stress concentration effect at artificial defect, and the magnetic signal fluctuates around the defect at late fatigue stage. The calculation results coincide with the initial MMM principle and can explain signal fluctuates around the defect. The modified J-A model can explain experiment results well, and it is fit for MMM field characterization.

Keywords

metal magnetic memory / Jiles-Atherton model / rotating bending fatigue / magnetomechanical effect / local equilibrium state

References

[1] DubovA. A.. A study of metal properties using the method of magnetic memory [J]. Metal Science and Heat Treatment, 1997, 39(9/10): 401-405

[2] DubovA. A., KolokolnikovS.. Comprehensive diagnostics of parent metal and welded joints of steam pipeline bends [J]. Welding in the World, 2010, 54(9/10): R241-R248

[3] RoskoszM., GawrilenkoP.. Analysis of changes in residual magnetic field in loaded notched samples [J]. NDT&E International, 2008, 41(7): 570-576

[4] YanC.-y., LiW.-s., DiX.-j., XueZ.-k., BaiS.-w., LiuF.-ming.. Variation regularity of metal magnetic memory signals with inspecting time-interval and location [J]. J Cent South Univ Technol, 2007, 14(3): 319-323

[5] JianX.-l., JianX.-c., DengG.-yong.. Experiment on relationship between the magnetic gradient of low-carbon steel and its stress [J]. Journal of Magnetism and Magnetic Materials, 2009, 321(21): 3600-3606

[6] XuM.-x., WuD.-b., XuM.-q., LengJ.-c., LiJ.-wei.. The MMM detection of rotating bending fatigue damage for 45QT steel [J]. Advanced Science Letters, 2011, 4(1–6): 1-6

[7] JilesD. C., AthertonD. L.. Theory of ferromagnetic hysteresis [J]. Journal of Magnetism and Magnetic Materials, 1986, 61: 48-60

[8] JilesD. C.. Theory of the magnetomechanical effect [J]. Journal of Physics D: Applied Physics, 1995, 28(8): 1537-1546

[9] RaghunathanA., MelikhovY., SnyderJ. E., JilesD. C.. Generalized form of anhysteretic magnetization function for Jiles-Atherton theory of hysteresis [J]. Applied Physics Letters, 2009, 95(17): 172510

[10] SquireP. T.. Magnetomechanical measurements and their application to soft magnetic materials [J]. Journal of Magnetism and Magnetic Materials, 1996, 160(1): 11-16

[11] LengJ.-c., XuM.-q., XuM.-x., ZhangJ.-zhong.. Magnetic field variation induced by cyclic bending stress [J]. NDT&E International, 2009, 42(5): 410-414

[12] SablikM. J., WilhelmusJ. G., SmithK., GregoryA., ClaytonM., PalmerD., BandyopadhyayA., FernandoJ. G., MarcosF. C.. Modeling of plastic deformation effects in ferromagnetic thin films [J]. IEEE Transactions on Magnetics, 2010, 46(2): 491-494

[13] LiH.-q., LiQ.-f., XuX.-b., LuT.-b., ZhangJ.-j., LiLin.. A modified method for Jiles-Atherton hysteresis model and its application in numerical simulation of devices involving magnetic materials [J]. IEEE Transactions on Magnetics, 2011, 47(5): 1094-1097

[14] MakarJ. M., AthertonD. L.. Effects of isofield uniaxial cyclic stress on the magnetization of 2% Mn pipeline steel-behavior on minor hysteresis loops and small major hysteresis loops [J]. IEEE Transactions on Magnetics, 1995, 31(3): 2220-2227

[15] XuM.-x., XuM.-q., LiJ.-w., LengJ.-c., ZhaoShuai.. In service detection of 45 steel’s rotary bending fatigue damage based on metal magnetic memory technique [J]. Advanced Materials Research, 2010, 97–101: 4301-4304

[16] DongL.-h., XuB.-s., DongS.-y., ChenQ.-z., WangDan.. Monitoring fatigue crack propagation of ferromagnetic materials with spontaneous abnormal magnetic signals [J]. International Journal of Fatigue, 2008, 30(9): 1599-1605

[17] YangE., LiL.-m., ChenXing.. Magnetic field aberration induced by cycle stress [J]. Journal of Magnetism and Magnetic Materials, 2007, 312(1): 72-77

[18] CraikD. J., WoodM. J.. Magnetization changes induced by stress in constant applied field [J]. J Phys D: Appl Phys, 1970, 3(7): 1009-1016

[19] SubraS.Fatigue of materials [M], 2003CambridgeCambridge University Press27-29