Extended arm excavator is our common engineering machinery. It digs pipelines in cities, repairs roads, remoulds new villages in villages, digs foundation in building sites, opens mountains in mines, cuts trees in forests, and has a wide range of applications. Even advanced equipment will show defects after a long time of use. Today excavator manufacturers will explain for you. The causes of cracks on the side plate of telescopic arm and the related matters of repairing methods are discussed. I hope I can help you.
1. Causes of cracks
Reasons for side plate cracks of elongated arm excavator: including air bubbles, micro cracks, slag inclusion and excessive processing of excavator, the original welding seam will produce micro cracks and gradually expand: performance differences between welding electrode and plate cracks: due to large-scale elongated arm excavator, it is difficult to use and reliable and effective thermal insulation measures, After welding, the welds around the base of quenching zone are cleaned thoroughly, resulting in the decrease of welding strength: the excavator has a large impact during vibration operation, and the cracking of welds is uneven.
2. Repair methods
Pre-welding preparation: Use manual grinding wheel to clean up the oil, paint and rust on the original weld crack. The welding cracks are cut through the air plane and cut to the main body of the side plate, and the hardened area of the base material is removed. After planing, the cutting lubrication (internal interface polished into V-grooves) is carried out with an angle grinding wheel. After cleaning and pink examination, it is confirmed that all cracks have been found and removed.
According to the existing maintenance conditions, the 5mm type E5015 (J507) or E5016 (J506) electrodes were selected, baked at 350 (?) for 2 hours, and then kept at 100 (?) to avoid the water absorption of the electrodes and accompanied by it. The welding current is 190-230A. Because the side plate of excavator is thicker, the preheated welding area should be 150 ~ 250 C before welding. In the welding process, segmented, symmetrical and backward welding can be used. In the process of welding cooling, hammer should be used to continuously impact the weld metal to eliminate the stress. When welding the corner of side plate, continuous welding should be stopped to prevent arc defects and improve the stress state of the joint.
After welding, spatter, slag and weld nodules should be thoroughly eliminated. The residual height of the weld should not be greater than 2.5mm. No cracks or other defects are allowed on the weld without magnetic particle inspection.
Extended arm excavator
3. Measures to Avoid Welding Corrosion
Stop polishing and rusting on the weld and apply anti-rust paint. In the excavation site, the manual rust removal can be selected according to the practice of root excavation. The defect is that the labor intensity of workers is relatively high and the labor cost is relatively high. The acid pickling solution with this function can also be made by using organic acid as the main base material, corrosion inhibitor, surfactant, rust remover, rust inhibitor and film forming agent. Rust removal, anti-rust and primer, after cleaning to achieve the purpose of rust removal and anti-rust.
The above contents are all about the causes of side plate crack of the elongated arm excavator and the repairing methods. I believe you will understand after reading, and you will know how to deal with it in detail when you encounter similar situations in the later period. If you have any other needs, you can contact us by telephone. For more information, please visit our website: http://www.rbaras.com.