摘要 |
A method (Figures 4 and 4A) for making ring rolling preforms (102) of substantially toroidal shape for ring rolling (84) into substantially rectangular cross-sectional wall shaped forging blank rings (104) to be precision forged (86) into near net ring gear forgings (106) for heavy-duty drive axle ring gears (14) is provided. The method, and the preform forging die (138) used therefor, allow a series of preforms having between eighty percent (80%) to one hundred percent (100%) of the volume of the toroidal cavity portion (150) of the preform die to be forged utilizing a common die. |