The precipitation of the microalloying elements in high strength low alloyed (HSLA) steel controls the strength of the steel greatly through grain refinement and particle hardening mechanisms. The current work simulates the precipitation of vanadium a hot rolling process for the optimized strengthening effect in a microalloyed steel. Taking into account the effect of deformation, cause of the drastic increase in the dislocation density, namely higher nucleation site density, it can be clearly seen that the precipitation of all species at dislocations, dominate the precipitation kinetics. The diffuse interface effect on the interfacial energy as well as a volumetric misfit of AlN at dislocations is also taken into account. The latter is because of its significant difference in the lattice parameter from the matrix. The presence of AlN at dislocations does not override that of V(C, N) as found in other cases with low density of dislocation. Slow cooling rate in the process ensures the consumption of the microalloying elements which in turn strengthen the product and minimise the production cost. The experimental verifications for the precipitates are performed by scanning transmission electron microscopy (STEM) as well as X-ray absorption spectroscopy (XAS) from synchrotron radiation.
Simulation of precipitation in V-containing hsla steel for the strengthening enhancement
MASSARO, Paolo;POLA, Annalisa;
2016-01-01
Abstract
The precipitation of the microalloying elements in high strength low alloyed (HSLA) steel controls the strength of the steel greatly through grain refinement and particle hardening mechanisms. The current work simulates the precipitation of vanadium a hot rolling process for the optimized strengthening effect in a microalloyed steel. Taking into account the effect of deformation, cause of the drastic increase in the dislocation density, namely higher nucleation site density, it can be clearly seen that the precipitation of all species at dislocations, dominate the precipitation kinetics. The diffuse interface effect on the interfacial energy as well as a volumetric misfit of AlN at dislocations is also taken into account. The latter is because of its significant difference in the lattice parameter from the matrix. The presence of AlN at dislocations does not override that of V(C, N) as found in other cases with low density of dislocation. Slow cooling rate in the process ensures the consumption of the microalloying elements which in turn strengthen the product and minimise the production cost. The experimental verifications for the precipitates are performed by scanning transmission electron microscopy (STEM) as well as X-ray absorption spectroscopy (XAS) from synchrotron radiation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
