WELDING OPERATIONS I - OD1651 - LESSON 1/TASK 1
(4) A properly made bead weld should leave little spatter on
the surface of the work (figure 14, view C, on the previous
page). When the arc is broken, the crater or depression in the
bead, shown in figure 14, view C, should be built up slightly.
This metal build-up should not overlap the top surface of the
weld. An overlap would indicate poor fusion at this point of the
weld. The depth of the crater at the end of the bead can also be
used as an indication of penetration into the base metal.
f.
Flat Position Welding (figure 15 on the following page).
(1) Butt Joints in the Flat Position. A butt joint is used to
join two plates having surfaces in approximately the same plane.
Several forms of joints are used to make butt welds in the flat
position. The most important of these forms are described in the
following subparagraphs.
(a) Plates 1/8 inch thick can be welded in one pass without any
special edge preparation being necessary.
Plates from 1/8 to
3/16 inch thickness can be welded with no special edge
preparation by making a bead weld on both sides of the joint.
Tack welds should be used to keep the plates aligned for welding.
The electrode motion is the same as that used in making a bead
weld.
(b) When welding 1/4 inch or heavier plates, the edges of the
plates should be prepared by beveling or by "J," "U," or "V"
grooving, whichever is the most applicable.
Single or double
bevels or grooves may be used depending on the thickness of the
plate being welded.
The first bead should be deposited to seal
the space between the two plates and to weld the root of the
joint.
This bead (also referred to as a layer or weld metal)
must be thoroughly cleaned to remove all slag before the second
layer of metal is deposited. When making multipass welds (figure
16, view A, on page 39), the second, third, and fourth layers of
weld metal are deposited using any of the weaving motions of the
electrode, as shown in figure 16, view B.
Each layer of metal
must be cleaned before depositing the succeeding layers.
37
Previous Page
