ABSTRACT
We report the results of measurements of first-order reversal curves (FORCs) for a thermally aged Fe-1wt%Cu alloy with different levels of rolling reduction. We find that the FORC distribution has a peak at high switching and interaction fields for samples with high rolling reductions and that this peak rapidly shifts towards lower fields after aging, which is associated with a narrowing of the peak. Conversely, after aging for more than 10,000 min, the peak exhibits an additional shift towards higher fields, which is associated with a broadening of the peak. These results indicate that both the microstructural homogeneity and the material hardening changes during thermal aging in a competitive way due to recovery and Cu precipitation, which is consistent with small-angle and wide-angle neutron scattering data.
Acknowledgements
SK would like to thank Dr Yojiro Oba at Japan Atomic Energy Agency for fruitful discussion about SANS data analysis. The neutron experiment at the MLF of the J-PARC was performed under a user program (proposal no. 2017B0129).
Disclosure statement
No potential conflict of interest was reported by the authors.