Manufacturing profiled conical cylinder by a semi-closed isothermal precision die forging technology

An improved semi-closed isothermal precision dies forging process has been used to produce successfully precision profiled conical cylinder forging. The semi-closed die forging significantly improved the forming quality and deformation homogeneity of profiled forgings, and greatly reduced die forging force by isothermal forging with three-stage variable speed. The static recrystallization during solution process was inhibited, and fine and even dynamic recrystallized grains and abundant sub-grains were obtained. In addition, the difference of the microstructure at each position was small and the distribution of grains and second phase particles was uniform. This significantly improved the mechanical properties and homogeneity of forgings, and the average values of tensile strength, yield strength and elongation reached 480.9 MPa, 387.8 MPa and 8.75%, respectively.