Special-shaped mandrel and machining device and method for flange

The invention provides a special-shaped mandrel and a machining device and method for a flange, and relates to the technical field of forming of flanges. The special-shaped mandrel comprises a central shaft and a plurality of arc-shaped pieces which is arranged on the central shaft in a penetrating manner; the arc-shaped pieces are connected successively; the heights of the arc-shaped pieces are gradually increased or reduced in the direction of the axis of the central shaft to form steps; and the shapes of the arc-shaped pieces are matched with the shapes of various sides of the flange. The technical problems that a plurality of dies need to be designed for forging of a flange in the prior art, the consumed time is long, and the machining cost is high are solved; forging is implemented by the arc-shaped pieces, machining and manufacturing of the flange can be realized by the special-shaped mandrel, and compared with a device for forging a flange by matching a plurality of dies in the prior art, the device ha