This increase in the strain could be due to significant shrinkage
forces in the weld area as compared to those in the base metal,
as this portion is subjected to expansion and contraction due to
localized heating.
Further, using the Scherer’s equation, the average particle size
(d) is estimated from the line broadening of the X-ray diffraction
peaks. The maximum intensity peak occurs at 2 = 45. To find the
average particle size (d) ofthe base metal and weld region and samples,
the high intensity peak is used and the average crystallite size
is calculated from Scherer’s formula by applying the X-ray diffraction
line broadening. The average crystallite size varies from 25 nm
to 26 nm for the base metal. For weld metal the average crystalline
size varies from 22 nm to 23 nm.