Abstract
In this research, the effect of microstructural changes of 2.25Cr-1Mo steel due to long-time exposure to high temperature (thermal degradation) on magnetic Barkhausen noise was investigated. Isothermal degradation heat treatment was performed at 630°C for up to 4800 hours. Microstructural parameters (size and number of carbides per unit area) were measured, along with magnetic Barkhausen noise (rms voltage and frequency spectrum), in order to investigate the relationships between them. The rms voltage of magnetic Barkhausen noise (MBNrms) was observed to increase rapidly in the initial 1000 hours of thermal exposure time and then very slowly thereafter. The initial sharp increase of MBNrms was attributed to rapid disappearance of a large number of needle-shaped carbides. Peak amplitude of the frequency spectrum tended to increase with increasing thermal exposure time.
| Original language | English |
|---|---|
| Pages (from-to) | 733-737 |
| Number of pages | 5 |
| Journal | Journal of the Korean Physical Society |
| Volume | 45 |
| Issue number | 3 |
| State | Published - Sep 2004 |
Keywords
- 2.25Cr-1Mo steel
- Carbide
- Magnetic Barkhausen noise
- Microstructure
- Thermal exposure