©
COPYRIGHT 2000 THE ESAB GROUP, INC. LESSON
III
b) E6011
electrodes are similar to E6010 except that sufficient
potassium com- pounds
have been added to the coating to stabilize the arc stream and allow
the electrode to be used on alternating
current. Penetration is slightly less than that
of the E6010 type. c)
E6012 electrodes
have several common names. In Europe, they are called
rutile (see Glossary) electrodes. Many
welders call them cold rods. The coating
contains large percentages of the mineral rutile (titanium dioxide), i.e.,
the titania referred to in the classification.
The arc has low penetration, and with
proper manipulation wide gaps can be bridged. Although the specifica-
tion calls for operation on either
AC or DC, the arc is smoother and spatter level
lower when direct current is used. d)
E6013 electrodes
also contain a large percentage of titanium dioxide in their
coating. They are designed to
have a low penetrating arc allowing thin sheet metal
to be welded without burn-through. The coating contains sufficient
potassium compounds to stabilize the
arc sufficiently for welding with alternat- ing
current. e)
E7014 electrodes
are related to 6013 electrodes except that iron powder has
been added and a heavier coating is
applied to the core wire. This results in higher
deposition rates with the E7014 electrode than with the E6013.
f) E7015
electrodes were the first of the low hydrogen electrodes.
They were developed
in the 1940's to weld hardenable steels such as armor plate. All of
the previously discussed electrodes
have appreciable amounts of hydrogen in their
coatings in the form of water or chemically combined hydrogen in chemi-
cal compounds. When hardenable
steel is welded with any of those elec- trodes
containing considerable hydrogen, "underbead cracking"
commonly occurs.
These cracks appear in the base metal usually just below, and parallel
to, the weld bead. Limestone
and other ingredients that are low in moisture are
used in the coating, eliminating this hydrogen induced cracking. The
coating is a low hydrogen, sodium type
that limits these electrodes to be used only
with direct current, reverse polarity. E7015 electrodes are not generally
available today having been replaced
by the E7016 and E7018 type. g)
E7016 electrodes
are very similar to the E7015 type except that the use of
potassium in the coating allows these
electrodes to be used with alternating current
as well as direct current, reverse polarity.
