Interaction Between Dislocations And Interstitial Atoms In
The Iron-Based Solid Solutions: A New Insight

Valentin Gennadiyevich Gavriljuk*, Vladyslav Mykolayovich Shyvaniuk, Sergey Myronovich Teus

G.V. Kurdyumov Institute for Metal Physics of National academy of sciences of Ukraine, Kyiv 03142, (UKRAINE)

PAGE NO: 123-139

ABSTRACT – DOI : https://dx.doi.org/10.47204/EMSR.1.2.2020.123-139

Interaction between dislocations and interstitial carbon, nitrogen or hydrogen atoms in the iron-based alloys is studied in terms of a local change in the electron structure within the atmospheres formed by interstitials around the dislocations. It is shown that, in case of transport of interstitials by dislocations, the locally enhanced metallic character of interatomic bonds by nitrogen and hydrogen increases mobility of dislocations, whereas the carbon effect is opposite. The enthalpy of migration of interstitial atoms in the solid solutions and that for binding between them and dislocations control the temperature for condensation of interstitials at dislocations. Above the condensation temperature, dislocations can move along with the interstitial atoms and velocity of dislocations is affected by the atomic bonds in the atmospheres: it decreases by carbon and increases by nitrogen and hydrogen. The temperature range of diluting the interstitial atmospheres during heating also depends on the both migration and binding enthalpies. A technical relevance of interaction between dislocations and interstitials in technology is demonstrated using examples of hydrogen embrittlement of metals, decomposition of cementite during cold work of pearlitic steels and deep cryogenic treatment of tool steels.