Having finished the welding processes, the specimens
were cut perpendicular to welding direction by using a
closed circuit saw cooled by boron oil in order to measure
the depth of penetration. The cut surfaces were
grained with 600, 800 and 1200 numbered grinding paper
and etched with 10% HNO3 solution. The macrostructure
photos were taken from these etched surfaces
by means of a Nikon Stereo Zoom optical microscope
in 10· magnification. The penetration measurements
were done from macro-structure photos by using a
new vision program. A schematic illustration of bead
penetration in welding