Tweco 400 TS Arcmaster - Manual (Page 49)

42
5 Non-metallic particles
are trapped in the
weld metal (slag
inclusion).
A Non-metallic particles may be
trapped in undercut from
previous run.
A If bad undercut is present, clean
slag out and cover with a run
from a smaller diameter electrode.
B Joint preparation too restricted. B Allow for adequate penetration
and room for cleaning out
the slag.
C Irregular deposits allow slag to
be trapped.
C If very bad, chip or grind out
irregularities.
D Lack of penetration with slag
trapped beneath weld bead.
D Use smaller electrode with
sufficient current to give adequate
penetration. Use suitable tools to
remove all slag from corners.
E Rust or mill scale is preventing
full fusion.
E Clean joint before welding.
F Wrong electrode for position in
which welding is done.
F Use electrodes designed for
position in which welding is done,
otherwise proper control of slag
is difficult.
Figure 10. Examples of Slag Inclusion