WELDING OPERATIONS I - OD1651 - LESSON 1/TASK 1
(b) Fillet welds for either tee or lap joints, on heavy plate
in the overhead position, require several passes to make the
joint. The first pass is a string bead with no weaving motion of
the electrode.
The second, third, and fourth passes are made
with a slight circular motion of the electrode with its top
tilted about 15 degrees in the direction of welding as shown in
figure 24, view C, on the previous page.
This motion of the
electrode permits greater control and better distribution of the
weld metal being deposited. All slag and oxides must be removed
from the surface of each pass by chipping or wire-brushing before
applying additional beads.
6.
Electric Arc Welding of Ferrous Metals
a. General.
All of the ferrous metals used on Army ground
equipment can be successfully electric arc welded, provided
normal care is used and the correct procedure followed.
The
following subparagraphs provide the welding techniques for four
of the most common types of ferrous metals found on this
equipment.
The description of welding techniques for other
ferrous metals may be found in TM 9-237.
b.
High-Carbon Steels.
(1) General.
High-carbon steels include those that have a
carbon content exceeding 0.45 percent.
Because of the high
carbon content and the heat treatment usually given to these
steels, their basic properties are to some degree impaired by arc
Preheating the metal between 500 to 800 Fahrenheit
welding.
before welding and stress relieving it by heating from 1200 to
1450 with slow cooling should be used to avoid hardness and
brittleness in the fusion zone.
Either mild-steel or stainless
steel electrodes can be used to weld these steels.
(2) Welding Technique.
(a) The welding heat should be adjusted to provide good fusion
at the sidewalls and root of the joint without excessive
penetration. High welding heat will cause excessive penetration
and puddling which in turn can cause large areas in the fusion
zone to become hard and brittle. Control of the welding heat and
excessive penetration can be accomplished by depositing the weld
metal in small string beads. The area of these hard zones in the
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