The spheroidization graphite cast iron material which possesses hard tunic, titanium hard tunic is formed by the surface of the spheroidization graphite cast iron which the die for press,

摘要

PROBLEM TO BE SOLVED: To provide a spheroidal graphite cast iron material which can be preferably used as a die material for press-forming various steel sheets, particularly, a high-tensile steel sheet and the like, and has a hard film with high adhesion formed on its surface.;SOLUTION: The spheroidal graphite cast iron material is subjected to nitriding treatment and has a titanium-based hard film formed on the surface. The spheroidal graphite on the surface has an average particle diameter of 30 μm or less.;COPYRIGHT: (C)2010,JPO&INPIT