WELDING OPERATIONS I - OD1651 - LESSON 1/TASK 1
rods, pistons, valves, and cams are considered unsuitable for
field welding. The principal reason for this is that these parts
have been previously heat treated to create desirable performance
characteristics (hardness or toughness); welding heat alters or
destroys these characteristics.
c. Determining the Welding Method. Automotive equipment such as
trucks,
tanks,
truck-tractors,
and
other
vehicles,
are
constructed from a large variety of metals that are heat treated
under various processes.
The metals used include copper alloys
of various types, carbon and alloy steels, titanium, aluminum,
magnesium, lead, among others.
The principal joining processes
that may be used are oxyacetylene, arc welding, brazing, and
soldering.
Oxyacetylene welding is used for welding of thin
metals and brazing of cast iron parts on automotive equipment,
while soldering is used for repairing such parts as fuel tanks,
radiators, and electrical connections.
This lesson, however,
concentrates on the arc welding processes for repair of
automotive equipment.
For further information pertaining to
oxyacetylene gas welding and soldering, refer to TM 9-237.
The
following subparagraphs describe weldable automotive parts and
the methods of repair.
This listing is an extract.
A more
complete list of repairable parts can be found in Tables B-2 and
B-3 of TM 9-237.
(1) Cast Iron, Cast Steel, Carbon Steel, and Forgings.
Generally, parts composed of these metals can be repaired by the
same procedure as that used for their assembly or by brazing or
soldering if the joining equipment originally used is not
available or suitable for the purpose.
For example, cast iron
and cast steel may be repaired by gas welding, arc welding, or by
brazing.
Parts or sections made of carbon steel originally
assembled by spot, projection, or flash welding may be repaired
by gas or arc welding. This same procedure is true of forgings.
(2) Cast Iron Engine Blocks (figure 3, on the following page).
(a) General.
Engine blocks may be repaired by welding or
brazing in the field only under extreme emergency conditions and
if a replacement block is not available.
Welding or brazing of
engine blocks is limited to those areas described below:
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