GRAY CAST IRONS

Sivi lijev jedan je od najkorištenijih materijala u strojogradnji. Veći dio ugljika izdvaja se u obliku listića (lamela) grafita, a manji dio u cementitu tako da je prijelom presjeka sive boje. Ima dvojnu mikrostrukturu koja se sastoji od nakupina listića i željezne osnove. Vermikularni i nodularni lijev su cijepljeni sivi ljevovi. Postupak cijepljenja je dodatno legiranje cjepivima koji pomažu izlučivanje grafita u obliku vermikula (crvića) ili kuglica (nodula). Vermikularna struktura grafita ima crvićast i izdužen oblik, dok u nodularnom lijevu prevladava nodularni (kuglasti) oblik.Gray cast iron is one of the most used materials in mechanical engineering. The greater part of the carbon is separated in the form of sheets (lamellas) of graphite, and the smaller part in cementite, so that the cross-section of the fracture is gray in color. It has a dual microstructure consisting of clusters of leaflets and an iron base. Vermicular and nodular mold are grafted gray moulds. The inoculation procedure is an additional alloying with inoculations that help the excretion of graphite in the form of vermicules (worms) or balls (nodules). The vermicular structure of graphite has a wormlike and elongated shape, while the nodular (spherical) shape prevails in nodular graphite