Vtl. Buono et al., MEASUREMENT OF FINE PEARLITE INTERLAMELLAR SPACING BY ATOMIC-FORCE MICROSCOPY, Journal of Materials Science, 32(4), 1997, pp. 1005-1008
Pearlite interlamellar spacing is an important parameter controlling d
uctility and strain hardening of carbon steels. Fine pearlite is the a
ppropriate initial microstructure for drawing high carbon steel with e
xponential strain hardening rate, leading to high final tensile streng
ths. The majority of optical and electron microscopy methods for measu
ring interlamellar spacing present difficulties when applied to fine m
icrostructures. Atomic force microscopy (AFM) was employed to investig
ate pearlitic steels lead patented at 510 degrees C and then cold draw
n to 86% reduction in area. Conventional specimen preparation techniqu
es for optical metallography were appropriated to produce high resolut
ion AFM images, on which measurements of minimum interlamellar spacing
, in good agreement with spacings estimated using the Embury-Fisher mo
del, were easily performed.