WELDING OPERATIONS I - OD1651 - LESSON 1/TASK 1
Nonuniform or rapid cooling will create internal stresses.
Welded engine blocks must be leak tested before placing them back
in operation. Leak testing procedures are specified in TM 9-237.
(3) Heat Treated Parts.
(a) The functions performed by certain parts in automotive
equipment require heat treatment during their manufacture.
Welding of these parts should not be attempted unless the repair
shop is equipped with suitable heat treating equipment for
handling these parts after welding.
(b) In some cases, alloy steels, or specially treated parts,
may be repaired by using a heat affected zone that is weaker than
the original heat treated part. In general, where it is possible
to heat treat the parts after welding, they should be annealed
prior to welding them.
Filler metal of the same composition or
properties as the base metal should be used, and the parts heat
treated after welding.
(c) In cases where the part to be welded is in a heat treated
condition, a stainless steel filler rod and the transition bead
welding method may be used as described below:
1 Deposit a layer of stainless steel (25 percent chromium, 20
percent nickel, or modified 18 percent chromium, 8 percent nickel
stainless steel rod) on the surfaces of the broken edges.
2 Weld the prepared edges with mild steel or high strength
filler metal.
Use 11 to 14 percent manganese or high strength
filler metal on the stainless steel layer instead of mild steel
where hardness and toughness are required. The weld then may be
covered with a layer of hard surfacing metal.
(d) These methods are useful in the field, but should be used
under emergency conditions only.
(4) Wheel Vehicle Components.
(a) Frames. The repair of frames by welding is not authorized.
Crossmembers and horns for the frame may be straightened,
repaired, and reinforced.
A commonly used method of repairing
and strengthening a broken or weakened crossmember or horn is
performed by using reinforcing plates as
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