Pa. Shenton et Cm. Sellars, GRAIN-GROWTH DURING THE THERMOMECHANICAL PROCESSING OF AUSTENITIC STAINLESS-STEELS, Ironmaking & steelmaking, 22(1), 1995, pp. 78-80
When modelling the microstructural evolution during multipass hot roll
ing of stainless, one of the largest ambiguities between different res
earch groups exists when describing grain growth after recrystallisati
on is complete. Experiments have, therefore, been carried out to inves
tigate the grain growth behaviour after recrystallisation of grade 316
L stainless steel under conditions relevant to industrial thermomechan
ical processing. Annealing experiments involving the reheating of recr
ystallised material over relatively long times showed that the materia
l exhibited classical parabolic growth. However, comparison with liter
ature data revealed large discrepancies between authors for values of
k in the grain growth equation d(2) = d(0)(2) + kt (see below for defi
nition of symbols). Plane strain compression tests enabled growth to b
e studied immediately after the completion of recrystallisation at sho
rt times relevant to interstand times in hot rolling. Results from the
se showed that growth followed a parabolic law, but of two distinct st
ages with differing growth rates. Initial growth after recrystallisati
on is relatively fast, but after a certain 'break point' growth revert
s to the same relatively low rate as experienced in annealing experime
nts. It is important then that the correct growth equation is applied
when modelling the microstructural processes during metal rolling. The
significance of different values of k on grain growth during multipas
s rolling has been demonstrated in this work and can, therefore, impro
ve the agreement between microstructural models and actual microstruct
ural evolution. (C) Institute of Materials.