SPHEROIDAL GRAPHITE CAST IRON MATERIAL HAVING HARD FILM, DIE FOR PRESS, AND METHOD FOR MANUFACTURING SPHEROIDAL GRAPHITE CAST IRON MATERIAL HAVING HARD FILM

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