A METHOD FOR THE MANUFACTURE OF A VESSEL BOTTOM WITH A FLANGE

摘要

A method for the manufacture of a vessel bottom with a flange includes the following steps: after heating of an ingot to a forming temperature, a preliminary forging (1) in shape of a circular plate having the height (H) and diameter (0) is made by free forging on a forging press; after the second heating to a forming temperature, the preliminary forging (1) is placed on a working plate (4) of a lower swage and the first male die (2) is pushed concentrically into the forging (1) to a depth necessary for the formation of a flattened segment (3); the flattened segment (3) is rotated by 180° and after its location on a machine tool a bellows (7) is formed by mechanical machining, which has in the centre a recess (X) and around the perimeter of the convex region (5) a recess (Y) having the radius (R); after heating, the bellows (7) is placed on a pre-prepared set of tools for the pressing via the convex part (5) upwards on a forming ring (8); the main male die (10) is pushed concentrically into the bellows (7) for pressing the bottom (11) by means of a reverse drawing, the bottom (11) being equipped with an external flange (6).