METHOD OF MANUFACTURING OF THIN WALL AXISYMMETRIC WELDED SHELLS WITH END THICKENED RINGS Russian patent published in 2015 - IPC B21D22/16 

FIELD: machine building.

SUBSTANCE: welded shell and rings are made out of structural complex-alloyed steel for cold strain. Initially blank of the shell is subjected to rotation drawing by several transitions with intermediate recrystallisation annealing and thermal deformation hardening and annealing reducing stress. The rotation drawing of the shell at each transition is made by rollers, installed in same plane of cross-section with displacement between each other in radial direction. After rotational drawing edges for welding are produced, they further are undercut. The ring blanks are initially subjected to heat strengthening as per modes of hardening and annealing of the shell blanks, then to machining providing ring thickness and ring edges for welding. Then shell and ring edges are prepared for welding. Then assemblage and welding of shell with rings are performed on expanding mandrel. The automatic welding is performed by GMAW using low-alloyed wire by single pass.

EFFECT: increased accuracy of dimensions.

6 dwg, 2 tbl, 1 ex