Shovel and Dragline Buckets
SHOVEL PARTS AND ACCESSORIES
Selection of one weld pattern over another when
hard-facing shovel and dragline buckets is important.
Welding Procedures: House rolls are generally made
One hard-facing alloy will not work satisfactorily
of high carbon steel and should be preheated to at least
under all wear conditions. Likewise, one hard-facing
500F. Mount roll on jig for downhand welding.
pattern will not perform the same under all wear
Rebuild worn rolls with recommended buildup
material in transverse beads across face. Machine or
grind to proper size (Figure 2-21).
A bucket working in sand with hard-facing beads
applied at right angles to the flow of material will have
a longer service life than one with beads applied
parallel to the flow.
A waffle pattern of beads gives even better protection
to a bucket because the pattern forms small pockets
where damp dirt becomes packed. This results in
abrasive soil working against more soil. Both the
hard-facing and the base metal are thus protected.
A bucket working in dry, large-sized slag with hard-
facing beads applied at right angles to the flow of
material will be subjected to high abrasive wear.
Beads applied in the same direction of flow will, in this
case, allow slag to ride on top of the hard metal beads
FIGURE 2-21. Hard-Facing Shovel House Rolls