Variation regularity of metal magnetic memory signals with inspecting time-interval and location

  • Yan Chun-yan  (严春妍)Email author
  • Li Wu-shen  (李午申)
  • Di Xin-jie  (邸新杰)
  • Xue Zhen-kui  (薛振奎)
  • Bai Shi-wu  (白世武)
  • Liu Fang-ming  (刘方明)


Influences of inspecting time-interval and location on varying behavior of metal magnetic memory (MMM) signals of defects were studied. Different areas in two precracked weldments were inspected at different time-intervals by type TSC-1M-4 stress-concentration magnetic inspector to obtain MMM signals. Mechanisms of MMM signals varying behavior with inspecting time and space were analyzed and discussed respectively. It is found that MMM signals don’t change with inspecting time-interval, since stress field and magnetic leakage field maintain unchanged at any time after welding. On the other hand, MMM signals differ greatly for different inspecting locations, because stress field and magnetic leakage field are unevenly distributed in defective ferromagnetic materials.

Key words

nondestructive testing metal magnetic memory inspecting interval inspecting location 


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  1. [1]
    DUBOV A A. A rapid method of inspecting welded joints utilizing the magnetic memory of metal[J]. Welding International(UK), 1997, 11(5): 410–413.CrossRefGoogle Scholar
  2. [2]
    DOUBOV A. Screening of weld quality using the magnetic metal memory effect[J]. Welding in the World(UK), 1998, 41(3): 196–199.Google Scholar
  3. [3]
    DOUBOV A A. Express method of weldments inspection using metal magnetic memory[C]// Proceedings of 7th European Conference on Non-destructive Testing. Copenhagen, Denmark, 1998: 1266–1273.Google Scholar
  4. [4]
    DOUBOV A A, DEMIN E A, MILYAEV A I, et al. The experience of gas pipeline stress-strain state control with usage of the metal magnetic memory method as compared with conventional methods and stress control means[J]. Welding in the World, 2002, 46(9/10): 29–33.CrossRefGoogle Scholar
  5. [5]
    DUBOV A. Principle features of metal magnetic memory method and inspection tools as compared to known magnetic NDT methods[J]. Canadian Institute for NDE Journal, 2006, 27(3): 16–20.Google Scholar
  6. [6]
    CHEN Xing, LI Lu-ming, HU Bin, et al. Magnetic evaluation of fatigue damage in train axles without artificial excitation[J]. Insight, 2006, 48(6): 342–345.CrossRefGoogle Scholar
  7. [7]
    REN Ji-lin, LIN Jun-ming, CHI Yong-bing, et al. Metal Magnetic Memory Technique[M]. Beijing: China Electric Power Press, 2000. (in Chinese)Google Scholar
  8. [8]
    LI Lu-ming, HUANG Song-ling, WANG Lai-fu, et a1. Research on magnetic testing method of stress distribution[J]. Trans Nonferrous Met Soc China, 2002, 12(3): 388–391.Google Scholar
  9. [9]
    HUANG Song-ling, LI Lu-ming, SHI Ke-ren, et al. Magnetic field properties caused by stress concentration[J]. Journal of Central South University of Technology, 2004, 11(1): 23–26.CrossRefGoogle Scholar
  10. [10]
    HUANG S L, LI L M, Wang X F. Magnetic evaluation method for stress annealing of ferromagnetic materials[J]. Materials Technology (UK), 2005, 20(1): 5–6.CrossRefGoogle Scholar
  11. [11]
    LI Lu-ming, HUANG Song-ling, WANG Xiao-feng, et a1. A study of stress induced magnetic field abnormality[J]. Trans Nonferrous Met Soc China, 2003, 13(1): 6–9.Google Scholar
  12. [12]
    LI Wu-shen, DI Xin-jie, BAI Shi-wu, et al. Feature analysis of metal magnetic memory signals for weld cracking-based on wavelet energy spectrum[J]. Insight, 2006, 48(7): 426–429.CrossRefGoogle Scholar
  13. [13]
    YAMASAKI T, YAMAMOTO S, HIRAO M. Effect of applied stresses on magnetostriction of low carbon steel[J]. Non-Destructive Testing and Evaluation International, 1996, 29(5): 263–268.Google Scholar
  14. [14]
    BULTE D P, LANGMAN R A. Origins of the magneto-mechanical effect[J]. Journal of Magnetism and Magnetic Materials, 2002, 251: 229–243.CrossRefGoogle Scholar
  15. [15]
    DOUBOV A A. About physical base of method of metal magnetic memory[C]// 8th ECNDT Proceedings Abstracts Book. Barcelona, Spain, 2002. 132.Google Scholar
  16. [16]
    TIAN Xi-tang. Welded Structure[M]. Beijing: China Machine Press, 1982. 47–52. (in Chinese)Google Scholar

Copyright information

© Published by: Central South University Press, Sole distributor outside Mainland China: Springer 2007

Authors and Affiliations

  • Yan Chun-yan  (严春妍)
    • 1
    Email author
  • Li Wu-shen  (李午申)
    • 1
  • Di Xin-jie  (邸新杰)
    • 1
  • Xue Zhen-kui  (薛振奎)
    • 2
  • Bai Shi-wu  (白世武)
    • 2
  • Liu Fang-ming  (刘方明)
    • 2
  1. 1.School of Materials Science and EngineeringTianjin UniversityTianjinChina
  2. 2.Petroleum-Gas Pipeline Research Institute of ChinaLangfangChina

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