Patent ID: 8047042
Filing Date: 2011-11-01
Classification: B21J

Abstract:
1. A press forging method comprising the steps of: setting a cylindrical steel ingot onto a die as a raw material; press forging the cylindrical steel ingot in a transverse direction where a forging ration of at least 1.2 is applied to the steel ingot, wherein the transverse direction indicates the press forging direction related to stretch forging, and the forging ratio equals a ratio of a cross section of a raw material before forging to a cross section of the raw material after forging; and thereafter, press forging in an axial direction where a reduction ratio of at least 1.7 is applied to the steel ingot, wherein the axial direction indicates a press forging direction related to upset forging, and the reduction ratio equals a ratio of a length of the raw material before forging to a length of the raw material after forging.