CEMP-E
TI 809-26
1 March 2000
electrodes. There are electrode classifications that have no required notch toughness (such as E6012,
E6013, E6014, E7024), but these are not classified as low hydrogen electrodes. There is no direct
correlation between the low hydrogen limits of various electrodes and notch toughness requirements.
(9) Low hydrogen, low-alloy SMAW electrodes, up through 550 MPa (80 ksi), as listed with
operating limitations and uses in Table C-4. For electrodes exceeding 550 MPa (80 ksi), see AWS A5.5.
(10) Electrodes providing a given level of notch toughness are listed in Table C-5. For the notch
toughness levels of higher strength electrodes, see AWS A5.5.
(11) Low hydrogen SMAW electrodes typically are supplied in hermetically sealed metal
containers. When supplied in undamaged containers, they may be used without any preconditioning, or
baking, before use. When SMAW electrodes are received in damaged containers or in non-hermetically
sealed containers, AWS D1.1 requires that the electrodes be baked prior to use, in the range of 260oC to
430oC (500 to 800F), to remove any residual moisture picked up from exposure to the atmosphere. The
electrode manufacturer's guidelines should be followed to ensure a baking procedure that eliminates
retained moisture, and these recommendations may vary from AWS D1.1 provisions.
(12) Once low hydrogen SMAW electrodes are removed from their hermetically sealed container,
or from the baking oven, they should be placed in a holding oven, also called a "rod oven" or "storage
oven", to avoid the pickup of moisture from the atmosphere. These heated ovens must maintain the
electrodes at a minimum temperature of 120oC (250F). Once the electrode has been exposed to the
atmosphere, it begins to pick up moisture. AWS D1.1 Table 5.1 limits the exposure time of various
electrode classifications. Higher strength electrodes, used to join high strength steels which are
particularly susceptible to hydrogen assisted cracking, are limited to very short periods.
c. Advantages, Disadvantages and Limitations. Generally SMAW has a lower deposition rate and is
less efficient, and is more costly than the other structural welding processes of FCAW, GMAW and
SAW. SMAW is seldom used as the principal process for structural welding, but is commonly used for
tack welding, fabrication of miscellaneous components, and repair welding.
(1) SMAW has the benefit of requiring relatively simple, inexpensive, portable, and easy to
maintain welding equipment. Gas shielding is not required. Holding ovens for low hydrogen electrodes
are required unless hermetically sealed containers are used to provide dry electrodes when needed.
SMAW is capable of depositing high quality welds, and is relatively tolerant of welding technique,
welding procedure variations, and wind. It can be used in areas with difficult access.
(2) Smaller prequalified weld bead sizes, maximum 8 mm (5/16 in.) in a single pass in the
common horizontal position, requires more passes for large welds, with additional cleaning time required
for slag removal. For long welds, because of the fixed length electrode, it may not be possible to
complete the weld without stopping, removing the slag to allow restarting the weld, and using additional
electrodes.
C-3
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