Modeling of Closure of Metallurgical Discontinuities in the Process of Forging Zirconium Alloy

Abstract

This article presents the results of testing the conditions of closing foundry voids during the hot forging operation of an ingot made of zirconium with 1% Nb alloy and use of physical and numerical modeling, continuing research presented in a previous thematically related article published in the journal Materials. The study of the impact of forging operation parameters on the rheology of zirconium with 1% Nb alloy was carried out on a Gleeble 3800 device. Using the commercial FORGE®NxT 2.1 program, a numerical analysis was performed of the influence of thermo-mechanical parameters of the hot elongation operation in trapezoidal flat and rhombic trapezoidal anvils on the closure of foundry voids. The analysis of the obtained test results was used to formulate recommendations on the technology of hot forging and the anvilgeometry, ensuring closure of foundry voids. Based on their research, the authors conclude that the shape of the deformation basin and the value and hydrostatic pressure have the greatest influences on the closure of foundry voids.

Using the Radial Shear Rolling Method for Fast and Deep Processing Technology of a Steel Ingot Cast Structure

“…The occurrence of identical orientation grain chains suggested unfinished potential dynamic recrystallization processes. However, this fact generally correlated with well-known work on radial shear rolling [24][25][26][27][28][29][30]51,52] and SPD processing generally [4][5][6], and indicated significant processing of the cast structure with its complete transformation into fine-grained structures close to nuclear engineering needs [53,54].…”

“…The technological chain usually includes smelting an ingot using a vacuum of at least 10-3 mbar, hot deformation processing (forging, pressing, and rolling), and cold deformation processing (pilger rolling, drawing, etc.) [27][28][29][30]. Due to the high quality requirements of semi-finished and finished products, these technological schemes are characterized by significant metal losses and low yields [31].…”