In the excavator maintenance training, we will talk about the repair of the boom. The repair of the excavator long reach fronts is very important. When inspecting the rust and cracks of the weld of the side plate of the excavating arm, it is necessary to scrape or polish the surface of the weld. Use a small hammer to lightly hit the weld when observing, and use a magnifying glass to observe if necessary.
How to repair, we must first understand the reasons for the cracks in the long reach fronts excavating boom, mainly including bubbles, slag inclusions and micro cracks in the original weld itself. When the excavator is overloaded, the original weld will produce micro cracks and slowly expand. When welding, the performance of the electrode and the plate does not match and cracks occur. Due to the large size of the excavating arm, it is difficult to adopt reliable heating and heat preservation measures. After welding, the hardened area of the base material around the weld cannot be completely removed, resulting in a decrease in the strength of the weld. During the operation of the excavator, the vibration and impact are relatively large, and the welding seam is cracked due to the uneven force at the welding seam.
How to fix it?
Preparations before welding: clean the oil, paint, rust, etc. from the cracks of the original weld with a hand grinding wheel. Gouging the weld cracks with gouging machine, gouging to the body of the side plate, and clean the hardened area of the base material welded in the past. After planing, use a corner grinding wheel to smooth the incision. After cleaning and pink inspection, confirm that all the cracks have been found and cleaned.
Also pay attention to the anti-corrosion measures of the weld seam, and the weld seam should be thoroughly polished, derusted and coated with anti-rust paint. In the excavation construction site, for the existing rusted welds, manual rust removal can be selected based on the actual situation. The disadvantage is that the labor intensity of the workers is relatively high and the labor cost is high; the method of pickling rust removal can also be used, that is, organic acid is used. The main base is equipped with composite materials such as corrosion inhibitors, rust removers, rust inhibitors and film-forming agents to prepare a pickling solution with rust removal, rust prevention and primer functions, which can achieve rust removal and rust prevention through cleaning. purpose.
In addition, during use, care should be taken to keep the excavator in a clean and dry environment, maintain good ventilation, and remove corrosive gases and moisture in time.