CAST IRON AND METHOD FOR ITS PRODUCTION Russian patent published in 2019 - IPC C22C37/04 C21C1/10 C22C1/10 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly to compositions and methods of producing high-strength cast irons with spherical graphite, and can be used in production of cast items, for example rolls of rolling mills. Cast iron contains, wt%: carbon 2.8–3.6, silicon 0.8–1.5, manganese 0.6–1.5, chromium 0.8–2.0, nickel 3.5–5.0, niobium 0.1–2.0, tellurium 0.0002–0.001, boron 0.02–0.08, iron and unavoidable impurities – the rest. Method includes melting in melting unit of base melt containing iron, carbon, silicon, manganese, chromium and out-of-furnace treatment, including spheroidizing modification in ladle and casting into molds, wherein base melt is obtained with the following composition, wt%: carbon 2.8–3.6, silicon 0.8–1.5, manganese 0.6–1.5, chromium 0.8–2.0, nickel 3.5–5.0, niobium 0.1–2.0, iron and unavoidable impurities making the rest, solidus temperature of alloy 1,120–1,128 °C is provided, heating charge to 1,480–1,500 °C, held therein for 30 minutes, discharging into ladle with modification of ferroboron on chute at outlet from furnace in terms of obtaining in finished alloy 0.02–0.08 wt% boron, modifying in the ladle with tellurium in amount of 2–10 g/t of the melt and during pouring into the mold, modifying with ferrosilicium FS65 of fraction 0.5–2.0 mm in amount of 1.0–3.0 kg/t of the melt being poured.

EFFECT: high ultimate tensile strength, ultimate bending strength and impact strength of cast iron.

2 cl, 1 tbl