Can poor material quality cause cracks in the welds?
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This post was last edited by Healthy eggs on 2011-1-6 at 22:47. Our company has recently welded a batch of carbon steel containers with dimensions of 750*6; the longitudinal seams were welded manually for the root portion and by submerged arc welding for the overlay. Currently, two pieces of equipment have cracks at the end of these longitudinal seams, one of which is approximately 7 cm long. What could be the cause of this? Could it be due to poor quality of the material? ?
This post was last edited by gzf7390637lv on 2011-1-5 at 13:21. 1. Does the poster need to specify what the material of the main body is? Is it high-strength steel? 2. What welding materials were used? Was there an issue with the choice of welding materials? 3. Confirm whether it is a delayed crack? 4. Was the correct welding process used, and was process qualification conducted? 5. Is the welding operator a certified welder? Personal opinion
First, it’s necessary to know what material it is made of; check the various chemical components listed in the warranty document to see if it’s high-strength steel, and also determine what type of cracks have appeared Also, what type of welding material is being used? Is it specifically designed for welding containers, and which manufacturer produces it?
Arc start and arc stop cracks are common welding defects that are largely related to the welder’s technique. Assuming the welding process is proper and the material is of good quality, a short dwell time at the end of welding is likely to be an important cause.
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Personally, I think there should be no problem with the material. During welding, cracks tend to form at the starting and ending points of welding; the main reason for this is shrinkage cracks resulting from uneven heating. When performing manual shielded metal arc welding, it is necessary to stagger the starting and ending positions of the weld to reduce the likelihood of cracks forming. Additionally, when welding longitudinal seams, arc-starting plates and arc-stopping plates are required.