SU1497226A1 - Method of grey cast iron - Google Patents

Abstract

The invention relates to metallurgy and can be used in the production of gray iron. The purpose of the invention is to reduce energy consumption while maintaining the quality of cast iron. A new method involves melting a mixture containing 0.4-0.6 grade silicon, overheating the melt to 1440–1450 ° C, holding the melt for 10–20 min, adding an additive of ferrosilicon based on the silicon content being 15–20% lower than the grade , release of the melt into the ladle in the amount of 0.4-0.6 of its mass, input of the modifier in the amount of 0.1-0.15% of the mass of the melt, release into the ladle of the rest of the melt and input of the modifier containing FESI, SICA and graphite with the ratio components (1-1,15) :( 1-1,15) :( 0.4-0.7), in the amount of 0.6-0.7 wt.%. The use of double modification in batch production of molten pig iron into the ladle allowed reducing power consumption when producing cast iron by 1.1-1.14 times. 2 tab.

Description

Of the% etenie about 1sit to metallurgy and can be used in the production of high frequency gray cast irons.

The purpose of the invention is to reduce energy consumption while maintaining the quality of cast iron.

The invention is illustrated by examples of specific performance. The choice of the boundary limits of the parameters of the proposed method for producing gray iron is due to the following.

Overheating of the melt below 1440 ° С does not ensure the homogenization of the melt, and overheating above 1450 ° С leads to an increase in the energy intensity and deterioration of the iron structure.

When ferrosilicon is introduced into the melt at the rate of obtaining a silicon content of less than 15% during the course of further modification, it is impossible to obtain a given brand of cast iron, since the silicon content will be higher than the specified one.

31497226

If the silicon content differs from the branded one by more than 20%, the modifier consumption increases unnecessarily.

When released into the ladle of less than 0.4 mass of the melt, the temperature of the latter exceeds the temperature of the modification, which leads to a lengthening of the process and a decrease in the effect of the modification.

If more than 0.6 mass of the melt is released into the ladle, then the effect of modification is weakened due to weak mixing when the remaining portion of the melt is released into the ladle.

With the introduction of a modifier of less than 0.1% by weight of the melt to process the first batch of cast iron, the modification does not occur, but the introduction of a modifier in an amount of more than 0.15% leads to an overrun of the latter.

The modification of the second portion of the melt is carried out with a modifier containing ferrosilicon, silicocalcium and graphite at a subsequent ratio of components: (1-1.15) :( 1-1.15): (O, 7-0.4), in the amount of 0.6-0.7% by weight of the melt.

The use of such a modifier in the specified amounts enhances the modifying effect and eliminates chill.

The proposed method and method of the prototype were implemented upon receipt of the iron brand SCH20 in an induction crucible furnace of the type of low-frequency plasma-2.5. The capacity of the furnace is 800 kW, the capacity is 1.2 t / h, the specific energy consumption for melting and overheating is 740 kWh / t.

Electricity consumption in the smelting of iron is given in table. one.

In tab. 2 shows the properties of castings when using complex

modifiers of the prototype method and the proposed method.

From the results table. 1 it follows that when using the proposed method for producing gray iron, the specific energy consumption decreases 1.1-1.4 times.

Claims (1)

Invention Formula The method of obtaining gray iron, melting a mixture containing 0.4-0.6 grade silicon, overheating the melt and loosening it for 10-20 minutes at an overheating temperature, introducing into the melt in two steps the material containing ferrosilicon, differing in that, in order to reduce energy intensity while maintaining the quality of the iron on, the melt is overheated to 1440-1450 ° C, after aging, ferrosilicon is introduced into it on the basis of obtaining silicon content by 15-20% below the mark, 0.4 to 0.6 mass of the melt is released into the ladle and the modifier is introduced in the amount of 0 , 1-0.15% by weight of the melt, then the rest of the melt is released into the ladle and a modifier containing ferrosilicon, silicocalcium and graphite is introduced in the following ratio of components: (1-1.15) :( 1-1.15) : (0.7-0.4), in the amount of 0.6-0.7% by weight of the melt. Table 1 790-800 800-825 190-200 190-200 0.65 700 200 . 2.0-2.6 2.0-2.6 2.0-2.6 2.0-2.6 2.0-2.6 2.0-2.6 2.0-2.6 2 , 0-2,6 2,0-2,6 2,0-2,6 1445 1450 1445 1445 1445 1445 1445 1445 1445 1445 Applicable modifier The amount of modifier by weight of the melt,% The complex modifier used in the prototype The modifier used in the proposed way FeSi: SiCa: Graphite 1: 1: 0.7 1.15: 1., 15: .0.4 1.1: 1.1: 0.5 Compiled by N.Kostornoy Editor N.Kishtulinets Tehred M.Hodanich Proofreader V. Girn to Order 4408/30 Circulation 530 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 0.12 0.12 0.12 0.12 0.1 0.15 0.12 0.12 0.12 0.12 0.65 0.65 0.65 0.65 0.65 0.65 0.5 0.6 0.7 0.7 700 690 700 690 700 700 700 720 700 700 200 210 200 200 200 220 200 210 220 220 table 2 Presence of chill - Bleached to 190-200) 18 mm 210 210 210 Without bleaching Subscription