Pengaruh Variasi Carbon Equivalent Untuk Kandungan 0,5% Cu Terhadap Sifat Fisis dan Mekanis Besi Cor Nodular

Cast irons are very important materials used in foundry engineering. Their physical and mechanical properties must be improved for better product quality. The aim of this research is investigate the influences of Carbon Equivalent (CE) on the physical and mechanical properties of nodular cast irons. The materials used in this research were nodular cast iron produced by PT Baja Kurnia at Ceper, Klaten, for with variations of CE content, namely 4,28; 4,40; 4,46; 4,60 and 4,68. Tests were done to observe the microstructure (graphite of diameter) and mechanical properties of the specimens including Brinnel hardness and tensile strength. Results show that for that CE 4,28; 4,40; 4,46; 4,60 and 4,68, average diameter of graphite were 40; 50; 35;40 and 42 µm, tensile strength increase relatively (525, 582, 605, 583 dan 2 811 N/mm ), with brinnel hardness between 180 to 219 BHN. Matrix ferrite and pearlite around graphite as observed in microstructures