RADIATOR GP 1630809 - Caterpillar

On larger adapters, wear plates may be attached in order to straddle the area near the bevel weld. The welds must not be in the area near the front of the base edge. Refer to Illustration 4.
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(6) Preferred orientation of wear plateWear plates should be welded from the front to the back. This is the preferred method. Welds from the front to the back are perpendicular to the primary loads on the adapter. Refer to Illustration 5.Hard facing materials are generally compatible with the chemistry of the heat treated adapters. However, welding sticks and wire consumable should conform to the stick and wires that are described in this publication.The adapters should be preheated to a temperature of 204 to 260 °C (400.0 to 500.0 °F) before hardsurfacing or welding. The welds must be allowed to cool slowly.Note: Extending the life of the straps of the adapters will not alter the normal effects of wear and fatigue on the adapter noses and the adapter welds.Base Edges
Due to the metallurgical content, base edges that are thicker than 25 mm (1.0 inch) must be preheated before welding. The base edge and the wear plates are preheated to a temperature of 204 to 260 °C (399.2 to 500.0 °F) when wear plates are installed at the factory. The wear plates are then welded at the front and rear edges and the wear plates are plug welded. Interpass temperatures are not allowed to fall below a temperature of 176 °C (350.0 °F).These temperatures are difficult to consistently attain in the field. Therefore, the addition of extra wear plates is not recommended.The following situations will cause hydrogen to be trapped in the welded area: improper preheating, rapid cooling, the presence of moisture and failure to use low hydrogen electrodes. These situations will also cause high internal stresses in the weld. Hydrogen embrittlement will cause premature cracking at the toe of the welds. This will cause a premature failure of the base edge.
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(7) Preferred locations for welding (8) Optional location for a plug weld (9) Do not weld along the sides.The potential for cracking in the welds can be reduced even if the desired temperature of 204 to 260 °C (400.0 to 500.0 °F) is not reached. The potential for early cracking in the welds can be reduced by welding along the front and back edges of the wear plate. The potential for cracking in the welds can be reduced by avoiding welding along