ASPECTS CONCERNING THE CRYSTAL LATTICE BEHAVIOR OF AUSTENITIC STEEL AT LOW TEMPERATURE
Two austenitic stainless steels for investigation under cryogenic condition were considered. Both X8CrNi18-12 and X12CrNi25-21 were investigated by X-ray diffraction at several cryogenic temperatures of 298 K, 223 K, 173 K, and 123 K. The crystal parameter and thermal linear expansion coefficient were calculated from the X-ray diffraction pattern. The major observation was the increasing of diffraction angles as temperature decreases. The X8CrNi18-12 crystal parameter presents a significant decreasing related to the same condition applied to X12CrNi25-21. We observe the same tendency for thermal linear expansion coefficient variation which means that X8CrNi18-12 becomes harder and more brittle than X12CrNi25-21 in the same cryogenic condition. Finally the X8CrNi18-12 proves to be useful for cryogenic applications which need high hardness instead of a good toughness and X12CrNi25-21 prove to be useful for cryogenic applications which need a better toughness.Key words: X-ray diffraction, austenitic stainless steels, elementary cell
Donohue J., The structure of the elements, John Willey, New York, 1985, p. 278 – 279
Shindo Y., Horiguchi K., Cryogenic fracture and adiabatic heating of austenitic stainless steels for superconducting fusion magnets, Science and Technology of Advanced Materials 4, 2003, p. 319–326
Wong F.M.G., Fatigue, fracture, and life prediction criteria for composite materials in magnets, S.B. Nuclear Engineering Massachusetts Institute of Technology, USA, PhD Thesis 1990
***, Republica Italiana, Decreto Ministeriale del 21 03 1973, Disciplina igienica degli imballaggi, recipienti, utensili, destinati a venire in contatto con le sostanze alimentari o con sostanze d'uso personale, 1973
Cullity B.D., Elements of X-ray diffraction, Addison – Wesley, Reeding, Massachusetts, 1978, p.506.
Arghir G., Caracterizarea cristalografică a metalelor şi aliajelor prin difracţie cu raze X, Litografia UTC – N, 1993
Constantinescu V., Orban R.L., Tehnologia Materialelor, vol. I, Litografia IPC-N, Cluj – Napoca, 1986
Kagan E.S., High Strength Steel for Cryogenic Temperature, translation from: Metallovedenie I Termicheskaia Obrabotka Metallov, no. 10, 1971, p. 18-20
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