Structure and heat resistance of zirconium alloys

Abstract

The effect of doping on the formation of the grain structure at argon melting, annealing and deformation of zirconium was studied on Zr—(0—2,5)Nb—(0—1)Cr—(0—0,5) Fe alloys. It was established that the processing determine condition of alloying elements in alloys. It is shown that the alloying and the cooling rate in the temperature range β → α-transformation can control the size of α-phase plates during casting and annealing. It was found that alloying effect on the deformation modes required for grain refinement as a result of dynamic recrystallization. It was found that the structure that is formed by dynamic recrystallization results in an increase of heat resistance of zirconium alloys. It was revealed that the coarsening of the grain structure of zirconium alloys is accompanied by formation and coagulation of particles of the second phase at the grain boundaries. It was found that the introduction of iron leads to stabilization of β-phase, it become apparent as the expansion of the temperature range of β-phase existence. Changing the size of the grain structure and the heat resistance after various treatments associated with the state of the alloying elements at grain boundaries. Deformation mode which crushes α-grain in zirconium alloys found regardless of the initial structure and alloying. Full text download