SU1310450A1 - Charge for making synthetic cast iron - Google Patents

Abstract

This invention relates to the field of metallurgy. The aim of the invention is to increase the hardness and strength of cast iron upon stretching, reducing its cost. The mixture of the proposed composition contains, wt%: flux 1.0-3.0; carburizer 1.0-5.0; ferrosilicon (45%) 4.0-8.0; ferromanganese (75%) 0.5-1.0; waste of ore-no-heat smelting of titanium slags - the rest. Waste ore-smelting of titanium slags contains alloying elements: chromium, nickel, molybdenum, titanium, vanadium, niobium, zirconium. The use of the charge of the proposed composition allows to increase the grade of the pig iron produced while saving valuable charge materials. 1 hp f-ly, 2 tab. I cl with i cl

Description

The invention relates to metallurgy and can be used in the foundry industry in the smelting of iron.

The purpose of the invention is to increase the hardness and tensile strength of the cast iron during stretching and reduce its cost.

 The mixture for melting sietichesky cast iron of the proposed composition contains - f live, wt,%:

Carburizer 1.0-5.0, 45% ferrosilicon 4.0-8, O. Ferromanganese 75% 0.5-1., 0 Flux1.0-3., 0 f5

Waste ore-smelting of titanium slags

Waste ore-smelting of titanium slags contain the following components, wt%:

Carbon1.0-2.0

Silicon0,2-0,4

Manganese, 1-0.3

Chrome 0.2-0.5

Nickel0.1-0.4

Molybdenum 0.2-0.5

Titan0.01-0.1

Vanadium 0.01-0,

Niobium 0.02-0.1 30

Zirconium 0.01-0.1

IronErest

Ferromanganese is introduced into the charge to bind in the castings of the molten pig iron sulfur present in the cast iron as an unavoidable impurity, into refractory non-metallic inclusions, which in the process of solidification of the casting are cent20

25

When a flux additive is less than 1.0 wt.%, The required amount of protective slag is not formed during the smelting process. The adsorption of precipitates from the metal melt deteriorates, which causes a decrease in the strength of the iron. The waste of metal increases, the heat loss increases, which causes an increase in the cost of electricity for heating. The melt is not protected from the external environment, the melt absorbs atmospheric gases that pollute the metal and reduce its strength.

With the addition of more than 3.0 wt.% Of the flux, it is difficult to conduct metallurgical processes, and the absorption of the carburizer and alloying elements is deteriorated due to the large amount of protective slag, which also affects the physicomechanical properties of the metal, such as strength and hardness. . The volume of the furnace is not used rationally, since less iron-containing component is introduced.

The carburizer in the amount of 1.0-5.0 wt.% Provides the necessary degree of carburization of cast iron, and the ferrosilicon in the cast iron forms small graphite inclusions having a vortex shape. Grinding of melted graph35 from the proposed mixture. Together with ferrosilicon introduced into the charge in the amount of 4.0–8.0 wt.%, The carburizer contributes to obtaining high-hardness ram iron for the absorption of graphite including 40 and tensile strength, since the research institute is dissolved in iron carbide , jjpjj such a ratio of the carburizer manganese increases its stability, contributing to an increase in the strength and hardness of iron.

The introduction of meteoric inclusions into the ferromanganese blend occurs at the expense of it 0.5 wt.% Is insufficient for the bonding that silicon forms additions of sulfur contributing to bleaching and crystallization centers to reduce the fluidity of the pig iron. Grease, shrinkage of the metal is liquefied. When carburized into the charge, when ferromanganese is added to the charge of 50 ra less than 1.0 wt.% And ferrosilicon is more than 1.0 wt.%, Manganese is in excess of 4.0 wt. The cast iron acquires a so-called white structure consisting of ledeburite and cementite. Such castings have 55 high hardness and brittleness and require special heat treatment - high-temperature annealing.

With the introduction of more than 5.0 wt.% And ferrosilicon to the carburizer charge

cast iron causes chill; cast iron. Such cast iron has an excessively high hardness and brittleness.

The flux in the amount of 1.0–3.0 wt.% During the smelting of cast iron from the proposed charge produces the formation of slag in the amount necessary for the adsorption of

Metal gases and various harmful inclusions that have a negative effect on the strength and other physical and mechanical properties of the metal.

When a flux additive is less than 1.0 wt.%, The required amount of protective slag is not formed during the smelting process. The adsorption of precipitates from the metal melt deteriorates, which causes a decrease in the strength of the iron. The waste of metal increases, the heat loss increases, which causes an increase in the cost of electricity for heating. The melt is not protected from the external environment, the melt absorbs atmospheric gases that pollute the metal and reduce its strength.

With the addition of more than 3.0 wt.% Of the flux, it is difficult to conduct metallurgical processes, and the absorption of the carburizer and alloying elements is deteriorated due to the large amount of protective slag, which also affects the physicomechanical properties of the metal, such as strength and hardness. . The volume of the furnace is not used rationally, since less iron-containing component is introduced.

The carburizer in the amount of 1.0-5.0 wt.% Provides the necessary degree of carburization of cast iron, and the ferrosilicon in the cast iron forms small graphite inclusions having a vortex shape. Grinding graphite from the proposed mixture. Together with ferrosilicon introduced into the charge in the amount of 4.0–8.0 wt.%, The carburizer contributes to obtaining cast iron with high hardness and tensile strength, since jjpjj is the ratio of carburizer

more than 8.0 wt.%, the strength of cast iron decreases in tensile strength, since complete ferritization of the metal matrix occurs, which is separated by silicon incorporation solutions in iron and graphite, acquiring a flaky shape. As an iron-containing component in the composition of the charge, waste of ore-thermal smelting of titanium slags (PTPT) containing valuable alloying elements, such as chromium, nickel, molybdenum and others, is used.

The composition of the mixture and the test results are summarized in table. one.

As can be seen from the table. 1, the composition of the charge for III smelting is optimal. The cast iron obtained from this charge is superior to the cast iron obtained from the rest of the melts, in terms of hardness and nickel, chromium, vanadium, molybdenum and other alloying elements that are contained in the GTPP waste noticeably ali -f5 under the conditions of crystallization and graphitization of synthetic cast irons. Due to the presence of alloying elements, the hardness and strength

stretching of cast iron due to grinding - 20 - stretching, which is due to. no graphite inclusions and changes in obtaining iron of a higher form. Cast iron made of such a brand. Somewhat inferior in this are the rest of the charge, it has a pearlite structure, and the cast iron coats obtained from the blend are responsible for high durability for you for II and IV heats. Pig iron, half-growth — is about 1.5 times higher at V smelting; its hardness is no higher than that of cast iron produced from

famous charge.

Example. In the arc furnace DSP-3 was held 5 experimental heats of synthetic cast iron. For II, III and IV, the charge was used, in which the components were contained within the proposed limits. For I melting-: lower, and for V melting - above the proposed limits. Up to 100% of the charge, additional-jj, wastes of GTPT.

The order of charge loading in the furnace: about 2/3 of the flux (lime); car bureau; waste smelting titanium slag.

The remainder of the flux was fed to the furnace as needed.

After the waste melted and the metal reached a temperature of 1350, the calculated amounts of ferrosilicon and ferromanganese were introduced into it.

The resulting synthetic cast iron was used to cast various machine parts.

Waste from the production of the electrode industry — graphite chips — was used as a carburizer; burnt lime and fluorspar were used as a flux.55 Formula

Before the release of smelting, the quality of the pig iron was carried out by pouring. 1. The mixture for smelting synthetic cast iron into the sandy form, containing carburizing wedge sample for bleaching agent, ferrosilicon is 45% and iron-only is inferior to the cast iron obtained at IV smelting, however, has a significantly lower tensile strength.

The grade, tensile strength and hardness of cast iron obtained from the charge for II, III and IV heats are significantly higher than those obtained from the known charge.

The cast iron obtained in the I melt has chill, which causes its high brittleness, low fluidity and great shrinkage, which adversely affects the quality of the melt.

The use of the proposed charge for smelting synthetic cast iron reduces the cost of 45 cast iron by using cheaper raw materials (see Table 2); increase in tensile strength of cast iron; increase in hardness of cast iron; increasing the grade of pig iron; saving valuable materials, such as pig iron, rolled iron, etc .; use for the purpose of valuable alloying elements.

of note

50

Standard specimens with a diameter of 30 mm were cast for research.

In order to obtain comparative data, the head of synthetic cast iron was also extracted from a mixture of known composition, adopted as a prototype. Samples with a diameter of 30 mm were also cast from this iron.

The obtained samples were used to determine the brand according to GOST 1412-79 by the limit and- ;. tensile strength and hardness of cast iron.

The composition of the mixture and the test results are summarized in table. one.

As can be seen from the table. 1, the composition of the charge for III smelting is optimal. The cast iron obtained from this charge is superior to the cast irons obtained from the rest of the melts by hardness and so on

 - stretching that caused-. The production of higher grade cast iron. According to these indicators, the cast iron obtained from the charge for II and IV heats is somewhat inferior. The cast iron obtained by V melting is not hard.

Formula

however, it is inferior to cast iron produced in IV smelting, however, it has a significantly lower tensile strength.

The grade, tensile strength and hardness of the cast iron obtained from the charge for II, III and IV heats are significantly higher than the cast iron obtained from the known charge.

The cast iron produced in the I smelting has chill, which causes its high brittleness, low fluidity and great shrinkage, which adversely affects the quality of the castings.

The use of the proposed charge for smelting synthetic cast iron reduces the cost of cast iron by using cheaper raw materials (see Table 2); increase in tensile strength of cast iron; increase in hardness of cast iron; increasing the grade of pig iron; saving valuable materials, such as pig iron, rolled iron, etc .; use for the purpose of valuable alloying elements.

of note

.513

ohm component, characterized in that, in order to increase the hardness and tensile strength of cast iron during stretching and reduce its cost, it additionally contains 75% ferromanganese, and, as an iron component, ore-thermal titanium slag melts at the ratio of components, wt.%:

Carburizer 1.0-5.0

Ferrosilicon

45% -4.0-8.0

0.5-1.0

1.0-3.0

f5

Tables The composition of the mixture and the properties of smelted iron

0.8 1.0 3.0 5.0

5, 5,

0.9 1.0

3.5 4.0

2.0 6.0 3.0 8.0 3.5 9.0

Characteristics of the resulting iron

III

rv

SC 35 350

SC 30 300

SC 18

According to prototype

MF 20

Melting of titanium slags Else 2. The mixture, according to claim 1, about tl and h and so that the waste of ore-thermal melting of titanium slags contain the following components, wt.%:

Carbon

Silicon

Manganese

Chromium

Nickel

Molybdenum

Titanium

Vanadium

Niobium

Zirconium

Iron

Cast Iron Tables

1.0-2.0

0.2-0.4

0.1-0.3

0.2-0.5

0.1-0.4

0.2-0.5

0.01-0.1

0.01-0.1

0.02-0.1

0.01-0.1

Rest

a 1.

0.4 0.5

94.4 93.5

241 220 210

200

219

Table2 Cost of 1 ton of batch materials for smelting synthetic cast iron

ez 58

28,

200

 ten

135

300

0, 8725 50,605

0.040 0.020

0.060

0,0075

1.0

8.0 0.2

8.1 2.25 69.155

Compiled by N.Shepitko Editor L.Pchelinska Tehred N.Glushchenko Proofreader L.Patay

Order 1870/27 Circulation 605 Subscription VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d, 4/5

Production and printing company, Uzhgorod, Projecto st., 4

8.0 0.2

8.1 2.25 9.155

0.8825 25.416 0.030 6.0 0.020 0.200, 060

0,0075

1.0

8.1

2.25

41,966

Claims (3)

55 The claims 1. The mixture for the smelting of synthetic cast iron, containing a carburetor, 45% ferrosilicon and iron • 5 melting of titanium slag 2. The charge, according to paragraph · 1, is unique in that the waste is an ore-containing component, characterized in that, in order to increase the hardness and tensile strength of cast iron and reduce its cost, it additionally contains ferromanganese 75 %, flux, and as an iron-containing component, waste from ore-thermal smelting of titanium slag in the following ratio of components, wt.%: Carburetor 1.0-5.0 Ferrosilicon 45% 4.0-8.0 Ferromanganese 75% 0.5-1.0 Flux 1.0-3.0 Ore Waste Mine - 5 thermal smelting of titanium slag contain the following components, wt.% Carbon 1.0-2.0 Silicon 0.2-0.4 Manganese 0.1-0.3 Yu Chromium 0.2-0.5 Nickel 0.1-0.4 Molybdenum 0.2-0.5 Titanium 0.01-0.1 Vanadium 0.01-0.1 fifteen Niobium 0.02-0.1 Zirconium 0.01-0.1 Iron Rest Table! The composition of the mixture and the properties of smelted cast iron Melting The composition of the charge, wt.% Carburetor Flux Ferrosilicon 45% Ferromar · ’· Ghanaian 75% RTPT waste I 0.8 0.9 _β 3.5 0.4 94.4 II 1,0 1,0 4.0 0.5 93.5 III s oh 2.0 6.0 0.75 88.25 IV 5,0 s oh 8.0 1,0 83.0 V 5.5. 3,5 9.0 1,2 80.6 According to the prototype 4.0 2.0 6.0 Continuation of table 1 Characteristics of the cast iron Melting Rolling trim GOST 1412-79 brand Ultimate tensile strength, MPa Hardness, HB Note 1 - - 500 Bleached eleven - Midrange 30 300 229 III. - Midrange 35 350 241 GU - Midrange 30 300 220 V _: - Midrange 18 180 210 According to the prototype 88.0 Midrange 20 200 219 131.0450 Table 2 The cost of 1 ton of charge materials for smelting synthetic cast irons Charge components Cost 1 t, rub. Charge According to the prototype Proposed (on the Middle level) Number, t Cost, rub. Number, t Cost, rub. Rolling trim 58 0.8725 50,605 - - RTPT waste 28.8 - - 0.8825 25,416 Carburetor 200 0,040 8.0 0,030 6.0 Flux Yu 0,020 0.2 0,020 0.20 Ferrosilicon 45% 135 0,060 8.1 0,060 8.1 Ferromanganese 75% 300 0.0075 2.25 0.0075 2.25 Total for 1 ton of charge - 1,0 69,155 1,0 41,966