Sl. Semiatin et V. Seetharaman, DEFORMATION AND MICROSTRUCTURE DEVELOPMENT DURING HOT-PACK ROLLING OFA NEAR-GAMMA TITANIUM ALUMINIDE ALLOY, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 26(2), 1995, pp. 371-381
Deformation behavior and microstructure development during hot pack ro
lling of the near-gamma titanium aluminide alloy Ti-45.5Al-2Cr-2Nb (at
omic percent) were established. Deformation behavior was investigated
through rolling at various nominal furnace temperatures and parallel m
odeling studies using a finite difference approach to predict temperat
ure transients during workpiece transfer from the furnace and during t
he rolling operation itself. Agreement between measured rolling pressu
res and predictions based on a rule-of-mixtures (ROM) average of the f
low stresses of the pack components (at the predicted temperatures and
strain rates within the roll gap) was excellent. As-rolled microstruc
tures were interpreted in terms of the Ti-xAl-2Cr-2Nb pseudobinary pha
se diagram, predicted temperature transients during rolling, and the s
tatic (no deformation) phase-transformation behavior of the program ma
terial. These results demonstrated the strong influence of furnace pre
heat temperature on microstructure development, as well as the tendenc
y for temperature transients due to radiation heat losses and roll chi
lling to suppress phase transformations.