Doing the primary

摘要

PROBLEM TO BE SOLVED: To provide a forging method wherein enhancement in productivity and cost reduction are attained.;SOLUTION: The forging method includes: a primary forming step where a forging raw material W is subjected to a primary formation by die forming to obtain a primary formed product W1 having a wall thickness reduction part having a small cross sectional area with respect to the forging raw material W; and a secondary forming step where the primary formed product W1 is subjected a secondary formation by the die forming to obtain a forged product W2. In the primary forming step, the closed forging wherein any projected burr is not formed is executed to a part corresponding to at least the wall thickness reduction part of the forging raw material W.;COPYRIGHT: (C)2010,JPO&INPIT