Welding of imported 316L equipment
Thread Content
The company has one imported 316L device, from the United States. During use, cracks appeared in the bracket. We are now using 316L welding rods for welding, but new cracks have emerged again, and they are still in the same areas – in other words, the welding did not seal the cracks properly. I would like to ask the experts: is it the welding rod that’s problematic or the welding method?
First, ensure that the raw materials are of good quality. Second, examine whether there are any flaws in the structural design. Third, for welding repairs, it is necessary to eliminate any existing defects first, especially cracks. Are there any pictures?
What was said upstairs is correct; we need to analyze the cause of the fracture – is it corrosion? Is it fatigue? Are it still weld defects? The original weld must be completely removed, and penetrant testing shall be carried out; welding may proceed only after it is found to be satisfactory
If both sides are 316L, this material has excellent weldability, so cracks should not occur. It’s likely that the brackets or containers are not made of materials such as 316 or 304; check the material composition
Recommended welding wire. 1. Check if the bracket is made of 316L. Regardless of whether it is or not, analyze the material and consult a welding engineer to determine the welding wire suitable for welding different materials together
The earliest occurrence of fracture cannot be determined at present. It seems that welding caused deformation of the sheet metal, and the operation of the equipment generated vibrations, which led to further fractures at the cracked areas due to stress.
Consider whether the structural design can be improved by strengthening certain sections to resist the effects of vibrations; additionally, think about carrying out non-destructive testing on the welds that are subject to vibrations to ensure welding quality
The question is not clearly stated: are cracks appearing in the scaffold itself, or are they in the welds between the scaffold and the main structure? If it is only the bracket itself that has a problem, direct welding repair will suffice ； If there is a problem with the weld, the cause must be identified; the crack in the weld should be removed by planing after the support is taken out, the area should be filled and welded, the surface polished, and then the support welded back in place. Be sure to conduct flaw detection when necessary to check for any new internal cracks.
Because it’s not possible to take photos in the explosion-proof area, the description isn’t clear enough. It is the location where the bracket is welded to the main body; both the bracket and the main body are mounted on springs. The movement of the equipment involves vibration, similar to the working principle of a vibrating screen, but the vibration frequency is not that high. The welds appeared at the junction where the foot is connected to the main body; multiple welds were carried out, and new cracks always appeared at those weld sites, which suggests that the welding was not done properly.
The root cause of the crack problems resulting from this type of vibration is the mechanical stress cracking between the bracket and the main body. For austenitic stainless steels, there is currently no effective permanent solution, and it’s not necessarily due to poor welding. A relatively effective approach is to replace the materials as much as possible or make some improvements to the welded structure, which can only extend the time before cracking occurs.
Vibration, ah. . . Then the structural design will need to be modified. . . Increase support, etc., to reduce amplitude