The cracking of the excavator's arm is a problem encountered by many digging friends. Because it is the main working part of the excavator, basically every action must be stressed. Although modern steel smelting technology has been very developed, it has not been Under the action of time, it can still ensure that the steel is not deformed, torn or worn. So what exactly caused the crack? How can we fix it?
There are many reasons that cause the excavator's large and small arms to crack.
1. A bucket that exceeds the original bucket capacity is used. For example, a 10-ton excavator using a bucket of 20 tons or more will cause the large and small arms to work abnormally and crack, so each model should use a bucket corresponding to the original bucket capacity.
2. The driver's operation mode is incorrect. Excessive force when digging a hard heavy object, strong hard digging, using the excavator as a crane, lifting heavy objects, etc. are the reasons for the cracking of the excavator's arm.
Third, continuous and long-term work load is too large, causing fatigue damage, especially mine work, large and small arm cracking is more common, do not work for a long time overload.
The heavy workload of the mine makes it possible for the excavator to break its arm
So what to do if the excavator's arm is cracked?
1. The welding place must be cleaned up before welding;
2. Certain preheating is required before welding;
3. Appropriate welding materials must be used for welding;
4. Welding must be ensured during welding;
Before welding, it must be cleaned, that is, the original cracked welded meat is removed, and it is ground with a cross-phase grinder or carbon arc gouging if possible, but the iron oxide must be polished after planing. It is necessary to preheat 100 degrees at the welding position if possible. And then use the diameter 3.2J507 electrode to weld, stop after a while, hit the weld seam and the edge of the weld seam with a hammer. After the welding is completed, keep hitting with the hammer until the weld seam basically cools. The purpose is to relieve welding stress, because it is impossible to do heat treatment after welding. Welding must be ensured during welding. If there is a large gap in the welding seam, a back plate can be added inside.
The electrode type is very important. If you want to understand what kind of material, you have to take some iron foam test, and the test will come out, and then the electrode will be distributed according to the composition. J507 welding rod is enough, the tensile strength is 50 kg, it is just a kind of structural steel. If you have used 507 before and can guarantee the penetration and crack, it is recommended that you change the J607, it should be enough.
In general, since each excavator breaks differently, we give the following example, which can basically explain most of the cases.
Step one, cut the side plates 180mm to 200mm from the left and right of the fracture, and the lower cover plate is cut by about 150mm based on the width of the side plates. In the picture, the blue part is the cut part of the side plate, and the red part is the cut part of the lower cover.
Step two: lay the liner under the broken cover, weld it well, and weld the cracks of the cover together. The welding process should be smooth without bubbles.
Step three: After welding, according to the blue part of the side plate cut in step one, re-cut an iron plate according to the size and weld it, and lining the inside. The liner is longer than the side plate that is sealed.
Step 4. After the previous step is completed, the bottom cover is not sealed. Before the bottom cover is sealed, the liner is still used first. Why is the liner used? How old is the liner? The liner board is simple, rough and effective. As shown in the figure below, after finishing the lining and sealing the bottom plate, the repair work is basically completed. Next, you can polish and make up the putty.
