Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Evaluation of 1Cr-1Mo-0.25V Steel Degradation Using Magnetic Barkhausen Noise

Barkhausen noise를 이용한 1Cr-1Mo-0.25V강의 열화도 평가

  • Published : 2002.07.01
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Abstract

It is inevitable to evaluate the life of turbine rotor because the operating periods of power plants need to be extended. For the test, seven kinds of specimens with different degradation levels were prepared by the isothermal heat treatment at $630^{\circ}C$. Magnetic methods utilizing Barkhausen noise coercive force($BN_c$) were applied to detect the degradation caused by thermal aging. Magnetic property of material is related with domain dynamics and that is affected by the microstructure of material. Therefore $BN_c$ is very sensitive to the microstructure change of the material. With the increase of degradation, $BN_c$ was decreased and this phenomenon is considered due to precipitations and grain size. The result was compared with Vickers hardness($H_v$) and coercive force($H_c$) to detect the relative variation, and was related with $H_v$ and YS to estimate the change of the mechanical properties with the degradation.

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References

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