256-2928 Recommended K Series Two Strap Adapter Welding Sequence {0679, 6800, 6801, 6802, 6803, 6805} Caterpillar

Excavator

All

Wheel Loader

All

The following weld application sequence is a general guideline. Always refer to the weld instruction sheet for the most current, and specific instructions and procedures.

Note: All weld start and stop points and all weld illustrations are general. These generalizations should be considered identical for both top straps and bottom straps with minor variances. These minor variances are dependent upon component strap geometry unless otherwise specified on base edge assembly drawings.

Note: Factory and production variations in weld starts and stops (points (C) to (D) in Illustration 2) is permissible. Stagger starts and stops when possible and consult a facility weld engineer for procedural variations within process capabilities.

Note: Weld zones must not exceed the maximum interpass temperature of 260° C (500° F).

Illustration 1	g03200356
(A) through (H) are weld start points or weld stop points (1) Adapter (2) Base edge

Illustration 2	g03203182
(A) through (H) are weld start points or weld stop points (1) Adapter (2) Base edge

Illustration 3	g03203181
Stagger all weld starts and weld stops (1st) through (6th) represent weld passes (1) Adapter (2) Base edge (3) Adapter to base edge weld (J) 12 ± 3 mm (0.5 ± 0.12 inch)

1. Preheat adapters and edge to 150° C (302° F) minimum temperature with a maximum interpass temperature of 260° C (500° F). Assemble adapter bevel with hard contact against the base edge bevel while equalizing the gaps of the adapter straps. The minimum gap requirement for equalization is 3 mm (0.12 inch) and must be equalized within ± 3 mm (± 0.12 inch) to base edge surfaces. Use soft wire spacers to hold position while tack welding at mid length in root of J-Groove on each side of the top strap.

2. Begin first weld bead at the front of top strap weld groove root at point (A) or (E) as shown in Illustration 1. Weld one continuous pass to the beginning of rear adapter arc (point (B) or (F)) or continue to weld around rear adapter arc ( (C) to (D)). Stagger all weld starts and weld stops as shown in Illustration 3. No weld stops and starts are recommended from (C) to (D) as shown in Illustration 2.

3. Move to the other side of the adapter and begin next weld bead at the front of top strap weld groove root at point (A) or (E) as shown in Illustration 1. Weld one continuous pass to the beginning of rear adapter arc (point (B) or (F)) or continue to weld around rear adapter arc ( (C) to (D)). Stagger all weld starts and weld stops as shown in Illustration 3. No weld stops and starts are recommended from (C) to (D) as shown in Illustration 2.

4. Return to original welded side and weld another pass. The interpass minimum temperature is 150° C (300° F) and the maximum interpass temperature is 260° C (500° F).

5. Continue welding alternate sides of the top strap until J-groove ( (A) to (E)) are filled. Do not apply fillet welds at this time.

6. Weld all top straps as per Steps 1 through 5.

7. Turn the edge over (bottom side up), and complete the procedures in Steps 1 through 4 for the bottom straps.

8. Continue welding alternate sides of the bottom strap until J-grooves ( (A) to (E)) are filled and complete. Start the first fillet weld pass at point (G) or (H). Start succeeding weld beads slightly behind the preceding layer to produce a rounded weld start end as shown in Illustration 3. Fillet weld bead passes should also be applied alternately on each side of the strap from front to back as described in Step 2. The final weld pass should be on the previously deposited weld near, but not on, the base edge weld toe.

9. Weld all bottom straps as per Steps 8 and 11.

10. Turn the edge back over (top side up), and complete the fillet welding of the top straps as per Step 8.

11. If necessary, use grinding to blend all start, stops, and weld toe undercuts. All weld stops (after initial pass) must tie into previously applied weld ends.

12. Allow all finished welds to slow cool.