QUARRYING, CRUSHING AND SCREENING

 

click here for:  Postle Wires & Electrodes for Quarries, Crushing and Screening

 

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.

 

 

GYRATORY CRUSHERS:

 

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.

 

 

Bell-Type:

 

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.

 

 

HAMMERS:

 

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.

 

 

SCREENS:

 

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.