When the annular parts of a spaceflight apparatus were welded, the centre of the rotation of electron gun and the centre of the annularweld are usually not superposed.
在真空电子束焊接航天器件的圆形焊缝时，由于工装等原因，出现电子枪回转中心与焊缝圆心不同心现象。
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During the welding process, the computer will modify the position of the electron gun based on the deviation to make the electron beam spot centered on the annularweld groove.
There are two types of cracks in the area next to weld seam of annular chains for mining during welding process, ie, teared type and punctured type cracks.