Effect of plastic deformation on anelastic mechanical losses in multicomponent substitutional austenitic alloys

Complex two-component peak of anelastic mechanical losses was observed in multicomponent substitutional austenitic alloys after prior plastic deformation. In AISI 316L, AISI 316LN, AISI 310 and AISI 304 austenitic stainless steels, this peak is situated in the wide range of temperature from 200 to 400 K. Characteristics of the observed peak for different thermo-mechanical treatments were studied employing low-carbon AISI 316L austenitic stainless steel. It is shown that the low-temperature component (peak P1 with maximum at 250 K) has a relaxation origin, while the high-temperature component (peak P2 located at 340-360 K) represents a transitional process developing in a deformed austenitic stainless steel during linear heating. The activation enthalpy and the pre-exponential factor of the relaxation time of peak P1 are 0.48 +/- 0.06 eV and 10(-11 +/- 1) s, respectively. Effects of prior cold deformation and heating rate on the observed anelastic mechanical losses are also described. The origins of the peaks are discussed in terms of interactions of dislocations with point defects generated by plastic deformation. (C) 2009 Elsevier B.V. All rights reserved.