Labor and materials would be too costly to cover the
entire surface area. The weld patterns act as dams, while
the “open” areas between the weld passes fill with dirt or
sand, making welds unnecessary. Another consideration
is hard material that does not compact into the nonwelded
areas. All types of welding designs are used to protect the
base material from wear depending on the type of earth
being moved. Design may include buttons, circles,
curved lines, zigzagged lines, and straight lines with
large and small gaps.
To ensure the welds will effectively prevent wearing
of the part, take into account the final use of the equip-
ment when choosing a pattern. Applications of hard-
facing on construction and industrial equipment are
shown in Figures 12-8, 12-9, and 12-10. Note the
patterns used and the amount of the original area left
uncovered.
Type of surfacing material, weld deposition time,
and final use of the equipment are three factors that deter-
mine if a welding operation is cost-effective. If the cost
of surfacing is too high, a new part may be used and the
old, worn-out part thrown away. This is especially true in
rework on tractors used for earthmoving. The front teeth
on the bottom of the blade typically are not surfaced
because the cost is too high. Instead, formed plates
covering the entire part are applied. Welding is used only
to attach the new plate to the old one.
Electrode and labor costs are high. However, filler
materials for FCAW are considerably less expensive than
filler materials for SMAW. When equipment is repaired
in the field, the use of portable equipment reduces down-
time and lowers costs for the operator.
Figure 12-11 shows a roll prepared for weld
surfacing. The weld is to be applied by an automatic arc
welding process using a FCAW filler material and
submerged arc welding neutral flux. The equipment and
tooling is adaptable for the application of this surfacing
material. See Figure 12-12 for the welding operation.
Application of the material by a two-head machine
is easy and practical. The results have exceptional quality
with a very even crown from end to end. Smoke is signif-
icantly reduced by using a submerged arc welding flux in
addition to the FCAW filler material.
Sometimes a surfacing operation is not practical
because of the design of the part. In these cases, wear
plates are used and attached by welding, Figure 12-13.
106 Flux Cored Arc Welding Handbook
Figure 12-8. Bucket housings for these front blade teeth were
hardfaced. Note the entire front blade is new; it is a replacement
part and has not been hardfaced.
Figure 12-9. The bottom edge of this blade is hardfaced to
protect it from wear.
Figure 12-10. The weld pattern traps dirt or sand in the
pockets. The areas are protected as if they were welded.