is one kind of cast iron that’s obtained in the first phase of one full graphitization. As all or most of the carbon materials surrounding us exist in flake graphite, and the corresponding fracture surfaces turn dark color and luster, hence the name’s obtained. All the said carbon materials contain gray iron, , mottled cast iron, inoculated cast iron, rare earth grey cast iron and etc.. And fracture surfaces of gray iron often turn light gray in appearance so this kind one is called as gray iron. It has advantages of low price, wide applications and large capacity, and the output of gray iron contributes 80% among the total one of cast iron all over the world.
Gray iron has certain strength but has low plasticity and ductility. This kind of performance has close relationship with both its own properties and existing forms appearing in the cast iron structure. Depending on better damping capacity of gray iron, gray-iron made bases, frames or other components and parts, installed into machinery equipments, can dampen all the vibrations brought by these ones well. Because of graphite composition of gray iron is a good conductor of heat, gray iron has better lubrication and heat conduction performances. Besides that, it’s much convenient to smelt the kind cast iron, and much easy to cast it. Furthermore, because of its good flow property, smaller line contraction percentage and volume contraction percentage plus uneasily cracked characteristic, gray iron is very applicable toand thin-walled castings with complicated cast structures like cylinder bodies, cylinder covers and other components applied in vehicles.