1. Preparation before welding: remove the oil stain, paint, rust, etc. at the crack of the original weld with hand grinding wheel. Use an air planer to cut the weld crack to the body of the side plate, and remove the hardened area of the previously welded base metal. After planing and cutting, use angle grinding wheel to grind the cut flat. After cleaning and pink inspection, confirm that all cracks have been found and removed.
2. Select according to existing maintenance conditions Φ E5015 (J507) or E5016 (J506) welding rods with the model of 5mm shall be baked at 350 ℃ for 2h, and then kept at 100 ℃ for heat preservation to prevent moisture absorption of the welding rods, which shall be taken when used; Welding current 190~230A. Due to the large thickness of the side plate of the excavator, the welded parts shall be preheated to 150~250 ℃ before welding; In the welding process, the segmented, symmetrical and reverse welding methods can be used; During the cooling process of the weld, the weld metal shall be continuously knocked with a hammer to eliminate stress; When welding at the corner of the side plate, in order to avoid rising and falling arc defects, continuous welding should be carried out to improve the stress condition of the connection.
3. After welding, spatter, welding slag and overlap shall be completely removed, and the weld reinforcement shall not be greater than 2.5mm. Magnetic particle flaw detection shall be carried out for welds, and no cracks or other defects are allowed.
