Recommended Products Crushing Applications
Procedures for Hardfacing Crushing Equipment
- Bars
Gyratory Crushers
Bell Type Crushers
Pulverizer Rolls
Clinker Rolls
Hammers
Screens
Cracked Mn Rolls
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Hardfacing
Procedures for
Crushing, Grinding & Pulverizing Equipment
BARS:
(Impact, Grizzly, Stripper, Deflectors)
1) Rebuild with
Postalloy 2865-FCO - at least two layers using stringer beads.
Do not overheat. Wait
until last weld bead has cooled to 600ºF(316ºC), or below, before
continuing.
When
parts made from manganese are rebuilt on a repetitive basis with standard
manganese hardfacing alloys, there is always a concern of heat
embrittlement in the base material, especially over time.
The use of Postalloy 2865-FCO will help to prevent this.
It acts as a heat insulator to the manganese base metal, helping it
stay below 500Fº(260ºC) during the welding operation.
2) Continue to within
1/4" (6.0 mm) of original dimensions using either Postalloy 2850-FCO
or 2865-FCO. Do not overheat.
3) Hardface to size with
wire suited to crushing operation.
a)
Postalloy 2820-SPL for heavy impact or hard to crush material.
b)
Postalloy 2834-SPL for low impact, more friable material.
Cone Crushers:
(Liners and Bowls)
Rebuild/hardfacing of cones can be done in about the same amount of
time as changing shafts from worn to new cones. Thus, the only cost to consider when rebuilding is the cost
of the wire versus the wear. A
final overlay of 2834-SPL is highly recommended in order to make this
repair cost effective.
New (use of proper hardfacing alloy will at least double life)
1) Using a stringer bead
technique, 1/4" to 3/8" wide (6 - 9 mm), and Postalloy 2834-SPL
wire, weld one layer on wearing surface.
2) Weld a second layer
with the same procedure in the heavy wear area.
3) If the wear area is
unknown, put the second layer 2" to 4" (50 - 100 mm) from exit
edge, about one quarter the surface distance up the crushing surface.
Used:
Do not allow the thickness of the cone to wear more than one half
to two thirds of the thickness or else the cone will be too thin to
rebuild.
1) Keep the cone as
assembled with the shaft included.
2) In the worn area,
rebuild with stringer bead technique using Postalloy 2865-FCO for first
two layers.
3) Continue to rebuild
to within 1/4" (6.0 mm) of desired size with same procedures, but
with Postalloy 2850-FCO build up wire.
4) Hardface as with new
cone, applying two layers of Postalloy 2834-SPL.
Rebuild/hardfacing of bells can be done in about the same amount of
time as changing shafts from worn to new bells. Thus, the only cost to consider when rebuilding is the cost
of the wire versus the wear. A
final overlay of 2834-SPL is highly recommended in order to make this
repair cost effective.
New:
1) Weld a single layer
two thirds of the surface distance up from the exit end.
Use a stringer bead procedure, 1/4" to 3/8" wide (6 - 9
mm), with Postalloy 2834-SPL wire.
2) Using the same
stringer bead procedure, apply a second weld layer one half of the surface
distance from the exit end.
3) Using the same
procedure, apply a third weld layer, starting 6" to 8" (15 - 20
cm) from the exit end, up one quarter of the surface distance.
Used:
1) Keep the bell as
assembled with the shaft included.
2) In the worn area
rebuild with stringer bead technique using Postalloy 2865-FCO for first
two layers.
3) Continue to rebuild
to within 1/4" (6.0 mm) of desired size with same procedures, but
with Postalloy 2850-FCO build up wire.
4) Hardface as with new
bell, placing 2nd and 3rd layer in area of greatest wear.
PULVERIZER:
(Rolls and Rings) 
1) Initially check wear
pattern. If heavily scalloped or with thin apertures or very uneven
surfaces, apply an initial layer with Postalloy 2865-FCO.
Use stringer beads of 1/4" to 3/8" width (6 - 9 mm).
2) Rebuild to size using
Postalloy 2834-SPL and stringer beads of 1/4" to 3/8" width (6 -
9 mm).
ROLLS:
(Rock Crusher, Clinker)
1) Postalloy 2865-FCO, a
high chromium build-up alloy, is recommended for first two layers on worn
rolls. Make sure customer knows to rebuild when the stainless
surface is seen.
2) Continue to build up
to within 1/4" (6.0 mm) of desired size with Postalloy 2850-FCO.
3) Cap with pattern to
crush material as desired with:
a)
Postalloy 2834-SPL wire for readily friable, hard rock material
(granite, quartz, high silica material).
b)
Postalloy 2820-SPL wire for hard to crush material.
New:
1) Weld a single layer
of surfacing wire on working face or faces 1/4 (6.0 mm) the length of the
hammer from top - use stringer beads.
a) Postalloy
2834-SPL for low impact, more friable material.
b) Postalloy
2820-SPL for heavy impact or hard to crush material.
2) Weld single layer on
top half of first layer using same procedure and wire.
Worn:
1) Rebuild to size with
Postalloy 2850-FCO using the stringer bead technique.
Keep hammer below 600ºF(316ºC) between welds.
2) Surface as new
hammers.
1) Insert carbon or
copper shapes, slightly tapered, into holes from exit side.
Weld a stringer bead around the circumference of shape using
.045" (1.2 mm) diameter - Postalloy 2832-SPL, 2834-SPL, 2836-SPL or
2839-SPL.
2) Weld a 1/2" to
3/4" (12 - 18 mm) wide weave bead over stringer bead.
REVIEW OF GENERAL HARDFACE and WELDING PROCEDURE:
1) Use Postalloy
2865-FCO - put at least two layers on worn parts.
When parts made from manganese are rebuilt on a repetitive basis
with standard manganese hardfacing alloys, there is always a concern of
heat embrittlement in the base material, especially over time.
The use of Postalloy 2865-FCO will help to prevent this. It acts as a heat insulator to the manganese base metal,
helping it stay below 500Fº(260ºC) during the welding operation
2) Balance of build up
can be done with Postalloy 2850-FCO wire.
3) Hard surface with
wires in relationship to material and action of part.
a)
With hard material (granite, quartz, etc.) and low to moderate
impact - surface with Postalloy 2834-SPL wire.
b) With softer material (clay, limestone, etc.) or if high
impact forces - use Postalloy 2820-SPL wire.
Make
sure non-magnetic parts (manganese steel) are kept below 600ºF(316ºC)
before welding each stringer bead. Do not use weave beads.
4. When preparing a
manganese part for hardfacing it is critical that all cracks are repaired,
and all areas that have spalled off be filled in and rebuilt to size.
We recommend that cracks be repaired with 2866-FCO and spalled
areas should be buttered and filled in with 2866-FCO.
Join
manganese to manganese with 2850-FCO
Join
manganese to carbon or low alloy steels with 285-FCO, 285-SPL, or
2865-FCO, 2866-FCO.
Join
stainless to itself or to other base metals with 30-SPL, 30-FCG, or
2866-FCO.
Join
carbon and low alloy steels with 306-FCO or 3044-FCG
Join
high carbon steels and tool steels with 30-FCG or 30-SPL.
HOW TO REPAIR CRACKED MANGANESE
ROLLS
Step 1.
Loosen all wedge bolts and wedges.
Step 2.
Drill a hole at each end of the crack.
Vee out the crack to provide a 60° angle for welding.
Remove all hardfacing adjacent to and back about 6" (15 cm)
from the edges of the crack.
Step 3.
Weld heavy 4" (10 cm) angle iron 1" (25 mm) from, and
parallel to, each side of the crack.
Use Postalloy 2866-FCO, or its electrode equivalent (Postalloy
206HD), to join the angle iron to shell.
Step 4.
Drill or burn 1-1/8" (28 mm) holes in each angle iron on
6" (60 cm) centers to accommodate 1" (25 mm) bolts.
Run bolts through angle irons and tighten nuts progressively to
bring shell together.
Step 5.
Use Postalloy 2850-FCO or 2865-FCO, or the electrode equivalent
(Postalloy 205 or 207) to fill in the crack.
Use weave or oscillating beads.
Step 6.
Scarf off angle iron and rehard-face where necessary.
Step 7. Secure wedge bolts and wedges.