WELDING OPERATIONS I - OD1651 - LESSON 1/TASK 1
settings, table 1, indicates the current to be used when welding
with bare or lightly coated electrodes.
The arc voltage will
vary from approximately 15 volts for 1/16 inch electrodes to 30
volts for 3/8 inch electrodes of either the bare or lightly
coated types.
Usually, a 3/16 inch diameter electrode is the
maximum size for vertical and overhead welding positions.
TABLE 1.
CURRENT SETTINGS FOR BARE AND
LIGHTLY COATED ELECTRODES.
(2) The mineral-coated type of shielded-arc electrode, which
produces a slag as a shield, requires a higher welding current
than the cellulose-coated type, which produces a large volume of
gas to shield the arc stream.
Table 2 on the following page
shows the current requirements for the mineral-coated and the
cellulose-coated types of electrodes.
The welding voltage will
range from 20 volts for the 3/32 inch electrode to 30 volts for
the 3/8 inch heavy-coated electrodes of either type.
(3) Shielded-arc or heavy-coated electrodes are used for most
welding operations on steel rather than the bare or lightly
coated types.
The heavy-coated electrodes allow higher welding
speeds, provide alloying elements into the weld metal by means of
the coating on the electrode, as is done with certain stainless
steel electrodes. The shielded-arc type of electrode is used for
welding nonferrous metals and certain alloy steels, particularly,
stainless steel alloys.
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