Influence of impurity atoms on the mechanical properties of group Va metals and alloys based on them

Methods of improving the high-tempera ture strength and corrosion resistance of vanadium and certain alloys used in reactors

“…The hardening of vanadium and other refractory metals with interstitial elements (in the concentration range of the existence of solid solutions) is insignificant owing to their high diffusive mobility and small solubility as compared to substitutional elements. However, in the process of deformation by tension, in some temperature ranges we recorded anomalous deviations of the temperature dependences of strength and of the conventional yield point from the expected ones, characteristic of refractory body-centered cubic metals containing no interstitual impurities [22].…”

“…2c, curve 3). For strain rates of about 5 9 10 .3 sec -l, the temperature ranges of dynamic strain aging of the V-A group metals are close and lie within 500-900 K [22]. We established that, in the temperature range of deformation strain aging, the concentration dependences of the maximum hardening of vanadium containing nitrogen and oxygen can be described as follows: ACy = A 9 CN+o, where C is the total concentration of interstitial elements (mass %) and A is the hardening coefficient of vanadium, close to 1700 MPa/mass %.…”

“…2) for specimens tested by temporary bending in lithium and sodium melts leached with lead (for comparison) [18,19] and isothermally soaked in these media [20,21], dynamic vacuum [22], and helium as a heat-transport medium [23] as well as for specimens-witnesses (that are in the medium but not deformed) showed that the influence of reactor media is quantitatively regulated by the test temperature, nature of the medium, duration of the interaction, and changes in the mechanical properties of the metal after isothermal soaking and in the process of deformation in the whole temperature range under investigation (Fig. 2a, c, d).…”