Excavator boom repair
Posted: Nov 22nd, '24, 02:25
When checking the weld corrosion crack of the side plate of the excavatorarm, it is necessary to scrape or polish the weld surface of the paint layer and rust. During observation, tap the weld with a small hammer, and observe with a magnifying glass if necessary.
1. Causes of cracks
Reasons for cracks in the side plate of the excavatorarm: including bubbles, slag inclusion and tiny cracks in the original weld itself, when the excavatoris overloaded, tiny cracks will occur in the original weld and slowly expand: Cracks occur when the welding rod does not match the performance of the plate: Due to the large volume of the excavatorarm, it is difficult to adopt reliable and effective heating and insulation measures. After welding, the hardening zone of the base metal around the weld can not be removed completely, resulting in a decrease in the strength of the weld. During the operation of the excavator, the vibration and impact are large, and the uneven force at the weld causes the weld to crack.
2. Repair methods
Preparation before welding: Use the hand grinding wheel to clean the oil, paint and rust at the crack of the original weld. The weld cracks are cut off by air gouging machine to the body of the side plate, and the hardening zone of the previously welded base metal is cleared. After planing, use Angle grinding wheel to smooth the incision (the inner interface is polished into a V-shaped groove). After cleaning and pink inspection, it is confirmed that all cracks have been found and removed.
According to the existing maintenance conditions, the Φ5mm type E5015(J507) or E5016(J506) electrode is selected, baked at 350℃ for 2h, and then kept at 100℃ to prevent the electrode from absorbing moisture. Welding current 190 ~ 230A. Due to the large thickness of the side plate of the excavator, the welding part should be preheated to 150 ~ 250℃ before welding; In the process of welding, it can adopt the method of segmental, symmetrical and backward welding; During the cooling process of the weld, the weld metal should be continuously knocked with a hand hammer to eliminate the stress; When welding at the corner of the side plate, in order to avoid the defects of take-off and fall arc, continuous welding should be applied to improve the stress condition of the joint.
After the end of welding, clear the bottom of the splash, welding slag and welding bump, weld residual height shall not be greater than 2.5mm. Magnetic particle inspection of the weld is carried out, and cracks and other defects are not allowed.
3. Anti-weld corrosion measures
Polish the weld bottom to bottom, remove rust and apply anti-rust paint. In the excavation construction site, for the existing corroded weld, the actual situation of digging can choose manual rust removal, the disadvantage is that the labor intensity of workers is larger, the labor cost is higher; Pickling and rust removal method can also be used, that is, organic acid as the main base, with corrosion inhibitor, surfactant, rust remover, rust inhibitor and film forming agent and other composite materials, to make pickling solution with the function of rust removal, rust prevention and primer, through cleaning to achieve the purpose of rust removal and rust prevention.
In addition, in the process of use, attention should also be paid to make the excavatoroften in a clean and dry environment, maintain good ventilation, and eliminate corrosive gases and moisture in time
Choose DIG-DOG for high-quality, customizable brush cutters for skid steers with fast delivery. Contact us today to discover how our superior products can enhance your land management tasks!
for more info just visit our website at www.dig-dog.com
contact # : +86 158 6218 2088
email : sales@bonovogroup.com
1. Causes of cracks
Reasons for cracks in the side plate of the excavatorarm: including bubbles, slag inclusion and tiny cracks in the original weld itself, when the excavatoris overloaded, tiny cracks will occur in the original weld and slowly expand: Cracks occur when the welding rod does not match the performance of the plate: Due to the large volume of the excavatorarm, it is difficult to adopt reliable and effective heating and insulation measures. After welding, the hardening zone of the base metal around the weld can not be removed completely, resulting in a decrease in the strength of the weld. During the operation of the excavator, the vibration and impact are large, and the uneven force at the weld causes the weld to crack.
2. Repair methods
Preparation before welding: Use the hand grinding wheel to clean the oil, paint and rust at the crack of the original weld. The weld cracks are cut off by air gouging machine to the body of the side plate, and the hardening zone of the previously welded base metal is cleared. After planing, use Angle grinding wheel to smooth the incision (the inner interface is polished into a V-shaped groove). After cleaning and pink inspection, it is confirmed that all cracks have been found and removed.
According to the existing maintenance conditions, the Φ5mm type E5015(J507) or E5016(J506) electrode is selected, baked at 350℃ for 2h, and then kept at 100℃ to prevent the electrode from absorbing moisture. Welding current 190 ~ 230A. Due to the large thickness of the side plate of the excavator, the welding part should be preheated to 150 ~ 250℃ before welding; In the process of welding, it can adopt the method of segmental, symmetrical and backward welding; During the cooling process of the weld, the weld metal should be continuously knocked with a hand hammer to eliminate the stress; When welding at the corner of the side plate, in order to avoid the defects of take-off and fall arc, continuous welding should be applied to improve the stress condition of the joint.
After the end of welding, clear the bottom of the splash, welding slag and welding bump, weld residual height shall not be greater than 2.5mm. Magnetic particle inspection of the weld is carried out, and cracks and other defects are not allowed.
3. Anti-weld corrosion measures
Polish the weld bottom to bottom, remove rust and apply anti-rust paint. In the excavation construction site, for the existing corroded weld, the actual situation of digging can choose manual rust removal, the disadvantage is that the labor intensity of workers is larger, the labor cost is higher; Pickling and rust removal method can also be used, that is, organic acid as the main base, with corrosion inhibitor, surfactant, rust remover, rust inhibitor and film forming agent and other composite materials, to make pickling solution with the function of rust removal, rust prevention and primer, through cleaning to achieve the purpose of rust removal and rust prevention.
In addition, in the process of use, attention should also be paid to make the excavatoroften in a clean and dry environment, maintain good ventilation, and eliminate corrosive gases and moisture in time
Choose DIG-DOG for high-quality, customizable brush cutters for skid steers with fast delivery. Contact us today to discover how our superior products can enhance your land management tasks!
for more info just visit our website at www.dig-dog.com
contact # : +86 158 6218 2088
email : sales@bonovogroup.com