PRODUCTION OF COMPACT VERMICULAR GRAPHITE CAST IRON

• Main Authors: SASAKI MASATOSHI, INOUE HISASHI, YOSHIDA CHISATO, TANIGUCHI KOUHEI
• Format: Patent
• Language: English
• Published: 03.09.1985
• Subjects: CHEMISTRY; METALLURGY; METALLURGY OF IRON; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS

PURPOSE:To produce stably compact vermicular graphite cast iron by desulfurizing the molten iron tapped from a blast surface then bisecting the molten iron and pouring the two molten metals into one ladle after subjecting one thereof to a de-Ti treatment to limit the content of Ti to a specific range and adding an Mg-REM alloy thereto. CONSTITUTION:The molten iron tapped from a blast furnace is put into a preliminary treating furnace 2 and is desulfurized and refined by which S which is an element to retard graphite spheroidization and decreases the yield of Mg of a graphite spheroidizing agent is removed. Such molten iron is bisected and one of the two molten irons is put into an oxygen blowing furnace 3 where the Ti contained therein is oxidized and is removed in the form of slag. Since Si and Mo are simultaneously oxidized and removed in this case, the deficient amt. of Si and Mn are additionally charged to adjust the components. The molten iron subjected to the de-Ti treatment is poured together with the one untreated molten iron 4 into a vessel 5 to control the content of Ti to a 0.02-0.08% range. An Mg-REM alloy is added to the molten iron under such conditions as to satisfy the equation (1) by which the compact vermicular graphite cast iron is stably produced.