Effect of Texture on the Snoek Relaxation in a Commercial Rolled Steel

Abstract

This paper reports that determination of the concentration of foreign interstitial atoms dissolved in ferrite strongly depends on texture in commercial rolled carbon-manganese steel. It was found that the Snoek peak observed in samples cut at the angle of 45° to the rolling direction (RD) is higher by around 45 % than for perpendicularly or transversely cut specimens. Strong anisotropy of the Snoek relaxation is explained with use of the three-dimensional orientation distribution function (ODF). The existence of direct relationship between the height of the Snoek relaxation and the texture components was proved and supported further by mechanical loss measurements in ultra-high purity polycrystalline α-Iron samples having the same texture but different grain sizes. In contrast to other results reported in the literature the effect of grain size on the Snoek peak is negligible in comparison to the strong influence of the texture. The results reported in this paper have important implications for steel industry and have already been put into practice for the last seven years

Internal Friction and Microstructure of Ti and Ti-Mo Alloys Containing Oxygen

“…It is tacitly assumed here, that the internal friction peaks might be estimated as single relaxation processes. Nonetheless, more detailed analysis should take into account the interaction between interstitial atoms [22][23][24][25][26][27][28][29][30]48], the anisotropy effect of Snoek peak [18][19][20][21], and grain size.…”

“…The internal friction spectra were resolved into constituent Debye peaks corresponding to different relaxation processes. The analysis of secondary features of internal friction peaks caused by the interaction between interstitial atoms and substitutional-interstitial pairs [22][23][24][25][26][27][28][29][30] as well as the anisotropy effect of Snoek relaxation [18][19][20][21], and the type of stress applied are outside the scope of the present study. Notwithstanding, it is now generally recognized that the secondary features are responsible for the broadening of Snoek peak, the variation in peak's temperature [21][22][23][24][25][26][27][28][29][30] and peak's height [18][19][20][21].…”

“…Mechanical spectroscopy [6][7][8][9][10][11][12][13][14] provides important information about the behavior of interstitial atoms in binary and ternary alloys such as the concentration of dissolved interstitial atoms in solid solution, diffusivity, solubility limit [6,[14][15][16][17][18][19][20][21], precipitation, and their interaction phenomena caused by interaction between relaxing entities [22][23][24][25][26][27][28][29][30], short-and longrange interaction of mobile point defects with dislocations [31][32][33][34][35][36][37][38][39][40][41], and strain aging. In general, the time-invariant harmonic stress field imposed on a sample containing interstitial atoms dissolved in solid solution yields splitting of free-energy levels of different elastic dipoles' orientations [17].…”

Snoek-Köster Relaxation. New Insights - New Paradigms

“…The relaxation parameters of the SK peak strongly dependent on experimental conditions which give rise to different dislocation structures (dislocation densities) and Cottrell cloud densities, cd. Nevertheless, H~~ is always higher than the activation enthalpy of the carbon Snoek peak in iron H~ = 0.878 eV [27].…”

Mechanical Spectroscopy Of Bearing Steel

“…It is well known that point defects in the octahedral sites of the body-centered cubic lattice (bcc) give rise to the well-known Snoek relaxation [7][8][9]11,[40][41][42][43][44][45][46][47][48], which shows the characteristic anisotropic behavior [47,48]. However, the Snoek peak [49] and the dislocation-enhanced Snoek peak are absent in martenisite due to the tetragonality of the martensite.…”