PENGARUH PENAMBAHAN UNSUR Cr DAN Cu TERHADAP KEKUATAN TARIK BESI COR KELABU FC20

Abstract

The mechanical properties of grey cast iron are influenced by cooling rate, thickness of casting, heat treatment,
liquid treatment and alloying. Some aplications of its materials need high strength grey cast iron. To improve its
tensile strength usually its added with unsures which known as carbide promoteur ie. Cr and Cu.
In these research the effect of Cr and Cu on the mechanicals properties of grey cast irons has been evaluated.
Base material FC 20 which alloyed with Cr 0,23 %, 0, 32% and 0,47% and Cu between 0,6% to 0,7% have been
tested. The tensile test and metallographyc examinations have been conducted to known of its efects.
From tensile test there is an improvement of tensile strength about 20% from 191MPa to 232MPa. However the
microstructure of specimens are same which are pearlitic grey cast irons, with graphite type VII (flake), A
distributions and size of graphite are 3-5.