Anelastic Phenomena and Cr₂N Precipitation in a High Nitrogen Austenitic Steel

Abstract

Internal friction (IF) and dynamic modulus measurements on a high nitrogen (0.8 wt%) austenitic steel in the temperature range from room temperature to 800 °C have been carried out by using a vibrating reed technique with electrostatic excitation and frequency modulation detection of flexural vibrations in the frequency range of kHz. The IF spectrum of the as-prepared material shows a broad peak superimposed to an exponentially increasing background. The discontinuous precipitation of Cr2N phase changes the characteristics of the peak. The results have been discussed by considering interstitial-substitutional (i-s) interactions.

Mechanical Spectroscopy Investigation of Defective Structures in Metals

“…MS has been extensively used by us to investigate several topics of metallurgical interest: structures of point defects and their effect on mechanical properties of Cr martensitic steels for nuclear fusion reactors [3][4][5][6][7][8][9][10][11][12][13], damping behaviour of Ti6Al4V+SiCf composite [14,15], structural stability of Ni base superalloys [16], microstructure evolution of FeAl B2-ordered alloy obtained by melt spinning [17], relaxation processes in high nitrogen austenitic stainless steels [18,19], damping of forged 7050 alloy [20], Young's modulus profile in kolsterized AISI 316 L steel [21], anelastic phenomena preceding the melting of metals [22] and accompanying structural transformations in the melts [23].…”