Recrystallization and texture evolution of warm-pilgered FeCrAl alloy tube during annealing at 850°C

Recrystallization annealing of warm-pilgered FeCrAl tubes was the key to reduce the cracking and control the microstructure and properties of the cladding tube. The recrystallization and texture evolution of warm-pilgered FeCrAl tubes were investigated. The recrystallization kinetics and textural evolution during annealing were characterized using microhardness measurements and electron backscatter diffraction. The 3D-microstructure of the warm-pilgered FeCrAl tube exhibited heterogeneous deformed grains of alpha-fiber and gamma-fiber orientation. The significant anisotropy results in different recrystallization kinetics in the axial and circumferential directions of the tube. The mirostructure maintains a stable grain size of similar to 22 mu m and an aspect ratio of 1.8 in the axial and circumferential directions within 0-600 min annealing time. The stable microstructure is due to the dispersion of fine Laves phase particles in the ferrite matrix. Quantitative texture analysis shows that the alpha-fiber texture decreased significantly and the gamma-fiber increased after recrystallization. During the annealing process, the alpha-fiber strong point texture component {112}< 110 > turns into{223}< 110 > and the gamma-fiber component {111}< 110 > turns into {111}< 112 >. The recrystallization and texture evolution of warm-pilgered FeCrAl tube is of great significance to preparation and microstructure control of final cladding tube. (c) 2022 Elsevier B.V. All rights reserved.