| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a metal member made of spherical graphite cast iron of a special composition and a press forming mold achieving high toughness and high hardness at the same time by devising a quenching process. <P>SOLUTION: The composition of the spherical graphite cast iron is by weight ratio C: 3.3-3.8%, Si: 1.8-2.4%, Mn: 0.3-0.5%, Mg: 0.03-0.06%, Cu: 0.4-0.6%, Ni: 0.3-1.2%, Cr: 0.3-1.0%, Mo: 0.3-0.5%, balance: Fe. Cu, Ni, Cr and Mo are added by suitable quantity and base hardness and toughness are secured by normal casting. Cutting edge portions or bent edge portions are then subject to flame hardening by forced water cooling for increasing hardness and suppressing deformation to the minimum. <P>COPYRIGHT: (C)2012,JPO&INPIT |
