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Weld Bead Characteristics
PENETRATION Weld
penetration is the distance that the fusion line extends below the surface of
the material being welded. Welding
current is of primary importance to penetration. As Figure 7-7 illustrates, weld
penetration is directly related
to welding current. An increase or decrease in the current will increase or decrease
the weld penetration
respectively. However,
we have seen that welding current can be varied without changing the wire feed
speed; namely, through
the variation of the tip-to-work distance. The effect of tip-to-work distance
on weld penetration is opposite
in nature to that of welding current. An increase in the tip-to-work distance
will decrease welding
current and penetration. Of course,
the converse is also true. In some applications, many operators have
found it helpful to use this property
to control penetration. Changing the tip-to-work distance while welding
prevents burnthrough when there are
discontinuities in material thicknesses or joint gap. Figure
7-7 - Effect of Welding Current on Weld
Penetration Carbon Steel-Short Arc C-25 Shielding
