The invention relates to the field of steel
forging, in particular to a method for
forging a superhigh-temperature
soft core of a die cast steel
ingot. The method comprises the steps that first, the poured steel
ingot with a
liquid core is subjected to superhigh-temperature die stripping; second, the poured steel
ingot with the
liquid core is placed in a thermos van for temperature equilibrium and then is conveyed to a
forging press, the steel ingot with the
liquid core is subjected to high-temperature pressure maintaining forging, solidified
tail end
branch crystals are fully broken, a large quantity of equiaxed
crystal structures are formed, shrinkage cavities and
porosity are eliminated, and dendritic segregation is lightened; and at last, general forging is conducted, and crystalline grains and structures are fully refined. The method breaks through the conventional method that the die cast steel ingot is forged after being completely solidified; a semi-
solid structure with excellent liquidity on the core part of the steel ingot and the huge
temperature difference between the surface and the core part are created through superhigh-temperature die stripping of the steel ingot with the liquid core; combined with a subsequent heavy pressure and pressure maintaining method, forced feeding and pressure solidification can be achieved; the problems of shrinkage cavities,
porosity, segregation and the like of the center of the steel ingot are solved, and the metallurgical quality is improved; the riser weight is lowered, the heating number of forging is decreased, and the service life of a die is prolonged.