Self-organizing phenomena in bainite steels

• Published in: Metallurgist (New York) 2008-05, Vol.52 (5-6), p.314-318
• Main Authors: Kopaleishvili, V. P., Kashakashvili, I. G., Kereselidze, L. B., Ioseliani, O. G.
• Format: Article
• Language: English
• Subjects: Alloys; Bainite; Characterization and Evaluation of Materials; Chemistry and Materials Science; Covalence; Ferrous alloys; Hydrogen embrittlement; Iron; Materials Science; Metallic Materials; Silicon; Solid solutions; Steels
• ISSN: 0026-0894; 1573-8892
• DOI: 10.1007/s11015-008-9051-x

Based on an analysis of existing data and our own research results, we made the following scientific hypothesis: a decrease in the lattice parameter for iron due to the effect of two factors — negative temperatures and silicon content — for t test < t Si and [Si] > 2.2% causes embrittlement of the iron (KCU = 0 J/cm 2 ) due to dominance of covalent forces. By causing the regular occurrence of new covalent binding forces between iron atoms, silicon contents in excess of the [Si] > 0.50% threshold in iron and Fe-C bainite alloys give rise to subsequent self-organizing phenomena, the development of new bifurcations (abrupt increases in hydrogen solubility and in the amount of austenite in the alloy; formation of two supersaturated solid solutions 〈 α + γ 〉; occurrence and reversal of “rejuvenation”). This hypothesis provides scientific explanations not only for the processes described above, but also for processes related to graphitization, weldability, floccene formation, achievement of high strength, etc. This scientific hypothesis will become the basis for new approaches in existing areas, e.g., for development of iron-based hydrogen-storage alloys (HSAs).