SPRING 0964269 - Caterpillar

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Read and understand the instructions from the supplier and the safety practices of your employer. Provide fresh air circulation to the welding helmet in order to avoid any illnesses that can be caused by long-term exposure to the welding fumes. The fresh air circulation will also remove any exhaled carbon dioxide that may be trapped by the welding helmet. Use proper eye protection, ear protection, and body protection while preparing the surfaces and while you are welding on the surfaces. Do not touch live electrical parts. Use a welding helmet with a filter plate that is at least Shade-11. Auto-darkening helmets are recommended as these helmets eliminate neck-strain from "helmet flipping" while greatly increasing the accuracy of electrode placement.Low hour base edge and adapter weld failures occur when critical recommended welding practices are ignored or altered during installation, replacement, or repair. Refer to the special instructions listed at the end of this discussion for welding-specific types of adapters.Bucket Ground Engaging Tool (GET) components such as base edges, adapters, and sidebars have chemistries and hardness values that require special attention when welding. Ignoring cleanliness of the weld area, recommended preheating, using improper weld wire and poor weld applications will lead to premature hydrogen embrittlement and resultant cracking failures. The following welding principles should be followed to ensure that maximum component durability is attainable:
Clean welding surfaces
Use of low hydrogen welding consumables
Proper preheating
Maintaining inter-pass temperatures
Slow cooling after welding is completedCleanliness:
Areas that will be subject to welding must be free of paint, rust, grease, oil, scale, and slag. Contamination by these components can cause weld cracking, weld porosity and lower weld strength.Low hydrogen weld consumables
Using low hydrogen weld consumables such as E7018 stick electrodes, E71T-1 or E70T-5 wire is important to prevent cracking due to hydrogen embrittlement. These low hydrogen weld consumables should have a diffusible hydrogen rating of no more than 5 ml/100 grams of weld deposit. These help to prevent hydrogen embrittlement by reducing the amount of hydrogen that is absorbed into the weld.Proper preheat temperature
Applying the proper amount of preheat before welding is critical to ensuring a good weld. Preheat helps to prevent distortion of the part due to uneven heating and helps welding by requiring less heat input from the welder. Preheating is critical on larger parts, where the large mass can rapidly remove heat from the welding area. Preheat an area on both sides of each adapter that is at least twice the thickness of the base edge to 190 – 232 °C (375 – 450 °F). A more uniform heat application can be obtained if the preheating is applied on the side opposite of the side to be weld.Maintaining interpass-temperature
As with preheating, maintaining an even temperature distribution while welding can help prevent distortion and improve weld quality. Inter-pass temperatures should be monitored and kept in the same temperature range as preheating of 190 – 232 °C (375 – 450 °F). Care should be taken with large parts. Large parts