· Home
· Table of Contents
· Methods & Instrumentation

Magnetization of ferromagnetic materials in geomagnetic field by mechanical strain - Prinicple of metal magnetic memory testing and diagnostic technique

Wei-Chang Zhong
Nanjing Gas Turbine Research Institute, 47 Northern Central Road,
Nanjiing, 210037, People's Republic of China
Contact

Abstract

1.Magnetization by machining and magnetization through operation

2.The magnetization by strain under a directional stress

3.The magnetization by unsymmetrical elastic-plastic strain under an alternative stress

4.The process of spontaneous magnetization

Fig 3: The spontaneous magnetization process of ferromagnetic materials. Fig 4: The diagram of magneto-elasticity phenomenon development
DB - residual induction change
Ds- cyclic load change
H e - externald magnetic field

5.Conclusion

Acknowledgment

References

  1. A. A. Doubov : Diagnostics of metal and equipment by means of metal magnetic memory. < Proceedings of ChSNDT 7th Conference on NDT and International Research Symposium > Oct. 1999. Shantou, China : 181-187
  2. Junmin Lin, Chunjing Lin, Fabing Lin, Hui Sha : A new nondestructive testing technique based on magnetic memory effect. ( Chinese Journal of )ááNDTññ2000 ; 22 ( 7 ) : 297-299
  3. Wei-Chang Zhong : The demagnetization for a rotor of 23 million Watts gas turbine.ááTesting and Evaluationññ1984, ( 3 ) : 25-27
  4. Wei-Chang Zhong : Preliminary investigation for the cause of magnetization by machining and magnetization through operation. The paper read out in The 2nd Conference on NDT of The Chinese Society for Electrical Power Engineering. Nov. 1981, Nailing, China
  5. Kai-Hua Zhao, Xi-Mo Chen : Electromagnetism. Higher Education Publisher, Beijing. Apr. 1978
  6. Xun-Fang Sun, Xiao-Shu Fang, Yao-Hong Lu : Strength of Materials. People's Education Publisher, Beijing. Sept. 1964

© AINDT , created by NDT.net |Home|    |Top|