V. Shrinivas et al., DEFORMATION-INDUCED MARTENSITIC CHARACTERISTICS IN 304-STAINLESS AND 316-STAINLESS STEELS DURING ROOM-TEMPERATURE ROLLING, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 26(3), 1995, pp. 661-671
The effect of grain size on the deformation-induced martensite (alpha'
) in 304 and 316 stainless steels (SS) during room-temperature rolling
has been studied. Samples of four grain sizes of 52, 180, 229, and 28
5 mu m in 304 and three grain sizes of 77, 125, and 200 mu m in 316 SS
have been rolled from 16 to 63 pet reduction in thicknesses to charac
terize the microstructures during the rolling deformation. The amount
of alpha' formed increases with increase in the emount of deformation
in both SS for a given grain size. The volume fraction of martensite f
ormed increases with a decrease in grain size in 304 SS, while the alp
ha' martensite formation has been found to be grain size insensitive i
n 316 SS. The volume fraction of alpha' formed in 304 SS is always hig
her than that in 316 SS for a fixed percent reduction in thickness and
grain size. This is attributed to the higher number of shear band int
ersections observed in 304 SS, which are considered to be the nucleati
on sites for the alpha' embryos. The lath martensite obtained at small
true rolling strains changes to blocky type at higher true strains. T
he morphology of alpha' formed has been discussed and its characterist
ics obtained from rolling deformation have been compared with those ea
rlier reported from the room-temperature tensile deformation.