Regarding the misalignment amount and edge angle
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We have a piece of equipment; when aligning the circumferential seam, we didn’t pay close attention. After welding, the deviation on both sides was quite large, reaching up to 10 mm. Quality inspection issued a rejection report, stating that the deviation after circumferential seam welding was excessive, at 10 mm, and therefore the product was rejected. The result was seen by the supervisor on site, who said that this way of describing it wasn’t very precise; it should be said that the axial edge angle of the circumferential joint exceeded the specified limit, reaching 10 mm, and it cannot be referred to as a misalignment amount. What he means is that when aligning the circumferential seams, one measures the misalignment of the two sides (with equal thickness); this is what is referred to as measuring the amount of misalignment at the seams ； If the two sides are not even after welding, it cannot be called misalignment; it should rather be referred to as the axial edge angle of the circumferential weld. I didn’t pay much attention to this issue before; I’d like to ask if what the supervisor said makes sense? Or are the misalignment amounts and edge angles the same; it doesn’t really matter which value is used, right? Is there a problem with writing the rejection notes this way? How do you write it in a standard way? Thank you!
This post was last edited by zhangjuhua on 2015-10-31 at 19:33 to sort out variable names and welding edge angles
Take a look at the previous diagram, or draw one to illustrate the actual situation: lol
Based on preliminary estimates, if there is a height difference between your two tube sections, then the supervisor’s claim is incorrect. . Misalignment refers to the difference in height between the two sides. . An edge angle is a sudden change at the joint of two welds. . (Sudden increases and decreases, such as the “narrowing” at the seam)
Edge angle and misalignment are two distinct concepts; during alignment, both misalignment and edge angle are present. The same is true after welding. The unevenness on either side of the weld is called misalignment; it is referred to as misalignment whether before or after welding. The value measured at the weld area using a gauge: if there is no misalignment, the values on both sides of the weld are the same; if there is misalignment, the values differ.
I think misalignment and edge sharpness are not the same concept; there can be edge sharpness without misalignment. One focuses on \"misalignment\", while the other focuses on \"edges\".
The supervisor is right; it should be considered a tolerance violation related to the edges and corners. Moreover, the deviation in the edge alignment should also be indicated as a separate violation, which means there are 2 violations in total.
The misalignment check should be carried out after the welds have been aligned, while the edges of the welds are measured after welding is completed. However, the misalignment of weld seams can also be detected after welding, which is different from corners. Of course, if spot welding is not done properly during assembly, it may also lead to further misalignment during welding, but this is the responsibility of the inspectors. The defective inspection reports came at the wrong time.