Author(s)

M. Goka & H. Nisitani

Abstract

Effect of surface and heat treatments on the ductility of spheroidal graphite iron with a cast surface M. Goka," H. Nisitani,* "Advanced Materials Research Laboratory, Hitachi Metals Ltd., Japan * Faculty of Engineering, Kyushu University, Japan ABSTRACT Although machined specimens of spheroidal graphite (SG) iron show excellent ductility specimens with a cast surface have very low ductility. This study reports how surface and heat treatments in the production process affect the ductility of SG iron with a cast surface. The research was conducted by observing crack initiation and propagation in bending tests,and by fracture mechanics analysis. INTRODUCTION SG iron SAE grade D4018 and D4512,which have a high ductility,are usually used for automobile suspension parts. These materials certainly show excellent ductility when machined,however specimens with cast surfaces have very low ductility. This fact is a serious roadblock to the application of SG castings. The obje

Keywords