The distribution law of horizontal cross section area of ring forging and ring blank is put forward to describe the rolling formability of conical ring with inner steps.
The cooling process of crankshaft blank before forging was simulated. The reliability of the simulation program was confirmed by comparison the change of simulated temperature with that of measured.
The forming defect of the bend forging and the influence of blank and die shape parameters are studied. All of these provide theoretical basis for practice.