Nozzle type non-axisymmetric part electron beam welding clamp and welding method thereof

The invention belongs to the technical field of nozzle type non-axisymmetric part welding, and relates to a nozzle type non-axisymmetric part electron beam welding clamp which comprises a base and an offset block, and a mounting hole used for being assembled with a rotary table of an electron beam welding machine is formed in the center of the base; the offset block is an L-shaped block composed of a vertical block and a horizontal block, the vertical block is connected with the base, a groove body is formed in the horizontal block, the nozzle type non-axisymmetric part to be welded is installed in the groove body, and the nozzle center line of the nozzle type non-axisymmetric part to be welded and the center line of the installation hole are collinear. In the assembling process, the nozzle type non-axisymmetric part to be welded is installed on the offset block, and the rotation center of a circumferential welding seam coincides with the rotation center of the base plate; then the base and the center of a ro