Nondestructive evaluation of low carbon steel by magnetic adaptive testing

Abstract

Three series of low carbon steel samples, plastically deformed by cold rolling to five consecutive stages of deformation, were investigated by the method of magnetic adaptive testing (MAT), typical by its low required magnetisation of samples. Samples in one series were magnetically closed; those in the other two series were magnetically open. Results of the nondestructive magnetic tests were compared with the results of destructive mechanical measurements of Vickers hardness and ductile–brittle transition temperature. Linear, sensitive correlation with low scatter of values was found between the magnetic and the two mechanical parameters for any shape of the investigated specimens. Based on these results, MAT is suggested as a highly promising nondestructive alternative of destructive Charpy impact tests for monitoring the irradiation embrittlement of surveillance samples in pressure vessels of nuclear reactors.

Keywords:

• nondestructive material evaluation
• magnetic hysteresis measurements
• magnetic adaptive testing
• steel degradation

Acknowledgements

The authors are obliged to the Universal Network for Magnetic Non-Destructive Evaluation for organisation of the round robin samples preparation and measurements, the presented paper being just one contribution to the complex view of the used materials. The work was supported by projects No.1QS100100508 and No.102/06/0866 of the Academy of Sciences and of the Grant Agency of the Czech Republic, by Hungarian Scientific Research Fund (project K-62466) and by the Czech-Hungarian Bilateral Intergovernmental S&T Cooperation.

Notes

^1. [email protected]

^2. [email protected]

Additional information

Notes on contributors

Ivan Tomáš

1. 1. [email protected]

Satoru Kobayashi

2. 2. [email protected]