Making of cold-resistant cast iron |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
IPC classes for russian patent Making of cold-resistant cast iron (RU 2509159):
 Method for ladle modification of molten cast iron with light-weight magnesium-containing alloy combinations / 2500819
In rear part of a ladle bottom, opposite its nose part, there located by means of an inclined chute depending on weight of treated cast iron is one or more molten welded tightly closed containers from steel sheets with thickness of 1.5…2.0 mm, with tightly packed spheroidising modifying agent in the form of magnesium-containing alloy combination and bulk volume of up to 10 kg; after that, the ladle is intensely filled with molten cast iron for the period of not more than 40 seconds with direction of a jet to a free part of the ladle bottom.
 Method for obtaining high-strength cast-iron with vermicular graphite by intra-mould modification using alloy combinations of fe-si-rem system / 2497954
Method involves loading to a reaction chamber of a pouring gate system of modifying agent charge in the form of Fe-Si-REM alloy combination providing initial concentration of rare-earth metals in molten cast-iron of 0.075%; then, after the casting mould is assembled, a lump of FS75 with the weight of 0.24-0.46% of metal consumption of the mould is laid in its pouring basin for graphitising pre-modification, and it is filled with molten cast-iron from the furnace.
 Method for obtaining nanostructured recarburising agent for out-of-furnace treatment of high-strength cast-iron with ball-shaped and compacted graphite / 2495134
Method involves preparation of carbon-containing composition containing the following components, wt %: anthracite 50-85, graphite scrap 5-25, broken electrodes 5-25, graphite structure 5-15 that is crushed to the fraction of 0.1-3.2 mm, burnt at the temperature of 500-1500°C, graphite spheroids are formed in the material structure at high specific pressure of up to 20 GPa and subject to high-temperature exposure at 1800-2500°C in a reducing medium so that graphite nanostructures with the size of up to 100 nm are formed, which represent graphite nanoclusters with a hexagonal pattern.
Production method of high-strength cast-irons with ball-shaped or compacted graphite based on nanostructured recarburising agent / 2495133
Proposed method involves melting of a charge in a melting unit, heat treatment of the melt at 1300…1650°C; at that, when obtaining cast-iron with ball-shaped graphite, primary modification is performed with nanostructured recarburising agent in the quantity of 0.10…0.25% of the melt weight, and secondary spheroidising modification is performed by means of a modifying agent containing 5…7% of magnesium, in the quantity of 1.2…2.0% of the melt weight, and when obtaining cast-iron with compacted graphite, primary modification is performed with nanostructured recarburising agent in the quantity of 0.10…0.25% of the melt weight, and secondary compacting modification is performed with a modifying agent containing 3…5% of magnesium and 3…6% of rare-earth elements in the quantity of 0.3…0.8% of the melt weight.
Method of production of aluminium iron with compact inclusions of graphite / 2487950
Proposed method comprises making iron melt with aluminium content of 9.8-19.7%, pouring said melt in metal mould placed in salt melt at 950-1100°C, cooling said melt and isothermal curing of crystallised casting at 950-1100°C for 0.5-2 hours.
Alloy combination for production of castings from high-strength cast-iron (versions) / 2480530
As per Version 1, alloy combination contains the following, wt %: silicon 22.0-30.0, magnesium 9.0-12.0, cerium 0.4-0.6, copper is the rest; as per Version 2, alloy combination contains the following, wt %: silicon 22.0-30.0; magnesium 9.0-12.0, misch metal 0.8-1.2, and copper is the rest.
Modifying agent for obtaining cast iron with spherical graphite / 2445387
Modifying agent contains the following, wt %: magnesium 7.0-9.0; cerium 8.0-10.0; iron ≤ 1.5; nickel is the rest.
 Cast iron properties influence method / 2444729
In cast iron properties influence method there measured by addition of magnesium to cast iron melt is content of oxygen in cast iron melt; at that, to cast iron melt there added is magnesium till oxygen content in cast iron melt at temperature of about 1420°C is about 0.005-0.2 ppm. At that, magnesium is added till oxygen content is less than 0.1 ppm, preferably between 0.08 and 0.1 ppm.
 Procedure for production of iron with vermiculite graphite / 2427660
Procedure consists in melting charge in electric furnace, in heating iron melt in it to temperature 1490-1510°C and in modification of produced melt in ladle with mixture containing complex addition alloy FSMg7 containing REM (rare earth metals) 0.3-1.0 %, magnesium 6.5-8.5 %, at amount of 0.2-0.5 % and 22 % silicobarium SIBAR22 at amount 1.5-2.0 % of weight of treated iron melt.
Procedure for production of cast iron with spherical graphite and austenite-ferrite metal matrix / 2415949
Cast iron is melt in electric furnace. At tapping into a ladle melt is modified at temperature 1370-1400°C with complex alloy consisting of silicon-barium at amount 70-80 % of alloy weight. Preliminary there are produced casts out of mottled iron with austenite-martensite matrix by casting into a raw sand-clay mould. To obtain austenite-ferrite structure in iron casts they are subjected to graphitising annealing at temperature 980-1100°C, to conditioning during 3-5 hours and to successive cooling with a furnace to room temperature.
Briquette used in manufacture of cast iron / 2247155
Briquette includes silicon-containing material, carbon-containing material, and cement as binder. Silicon-containing material includes metallurgical silicon carbide and carbon-containing material includes carbon-siliceous mixture.
 Modifying agent / 2247170
Claimed modifying agent contains (mass %) ferrosilicon barium 0.5-5.0 and gypsum 25-5 %.
Method of production of ingots made out of mottled cast iron with austenitic-bainite structure / 2250268
The invention is dealt with metallurgy, in particular, with development of a method of production of mottled cast irons with globular graphite, which may be used for manufacture of components being worn under action of increased loadings. The method provides, that the mottled cast iron is melted down in the induction furnace, the liquid melt at pouring into a ladle is modified with magnesium-bearing addition alloys for formation of the ball-shaped graphite impurities in the ingots and during casting into a sandy-argillaceous mold expos it to inoculating modification. The ingots after crystallization are pulled out from the molds at the temperature of 900-1000°C, transposed to a furnace with temperature of 950-1000°C and keep there during 10-30 mines. After the aging the ingot is exposed to quenching in an isothermal bath at the temperature of 300-320°C within 1-1.5 hour. At that they use the cast iron of following chemical composition, (in mass %): carbon - 3.2-3.4, silicon - 3.0-3.3, manganese - 0.3-0.4, magnesium - 0.04-0.07, molybdenum - 1.5-1.7, nickel - 2.2-2.6, sulfur - 0.01-0.012, phosphorus - 0.06-0.08, iron - the rest. The invention allows to obtain a mottled cast iron with globular graphite and austenitic-bainite structure, high impact resistance, strength, hardness, wear resistance and quasi-isotropy.
Modifying master alloy for cast iron producing method / 2277589
Method comprises steps of preparing, heating, pouring and crystallizing melt under protective flux. Melt is heated till temperature higher than liquidus temperature t1 by 10 - 99°C; pressure value is in range 10-3 - 0.9 x 10-1 MPa. Invention allows prepare modifying master alloy with easy-to-melt magnesium-containing component, with high density and uniform distribution of properties in the whole volume.
 Semifinished product of foundry cast iron and method of its production / 2312161
Proposed semifinished product is made from composition system of white cast iron. Structure contains, independently or in complex, spheroidal or flattened particles of graphite whose outer surface is partially or fully coated with ferrite. Particles are dispersed at density of 50 particles/mm2 or more. Cast iron is produced by casting the melt of white cast iron constituents containing the spheroidizing agent. After casting, rolling and heat treatment are performed for obtaining spheroidal particles of graphite or heating and hot rolling are performed for obtaining flattened particles of graphite.
Complex modifying agent for producing cast pieces of cast iron with vermiculite or compact graphite / 2323270
Complex modifying agent contains next relation of components, mass %: magnesium, 0.5 - 10; calcium, 0.1 - 10; aluminum, 0.1 - 10; silicon, 30 - 80; total content of cerium and yttrium, 0.5 - 15; manganese, 0.1 - 15; lanthanum, 0.001 - 10; magnesia, 0.001 - 5; total content of oxides of rare earth metals, 0.001 - 10; iron, the balance.
Synthetic cast iron production method / 2324742
Invention concerns the siderurgy area and may be used when manufacturing the remelting fabricating parts that are used in the cast iron foundry production. The metal stock is loaded for melting inside an induction furnace until the melted down composition is obtained. In the furnace, upon the mirror of fusion the carbonates of the alkaline-earth metals are introduced in amounts of 10-20%, and the carboniferous material depending upon the required chemical composition of cast iron. The invention permits to intensify impregnation with carbon process, eradicates occurrence of refining foam and facilitates the sulfur removal.
 Fluxed cored wire filler for desulfurising and modification of cast iron / 2337972
Invention concerns metallurgy field and can be used in foundry. Particularly it is used for desulfurising and modification of cast iron and receiving of cast iron products with structure of globular and vermicular graphite. Filler contains, wt %: 18÷75 magnesium, part of which is introduced in metal phase; aluminium, barium, calcium, titanium, rare-earth metals at its total content 1÷10, and also iron and silicon (as the rest) - in the form of one or several materials, choose from group, including ferrosilicium, magnesium - iron - silicon alloy; mixture of metal silicon with cast iron and/or steel rattle, and/or chip, and/or powder. In filler content can also be included passivator in the form of one or several materials from group, including fired dolomite, calcium fluoride, calcium carbide, silicon carbide, soda, in amount which is a part of total content in filler of iron and silicon.
 Control mode of process for manufacturing graphite and high-duty cast iron with globular and vermicular graphite for casting receiving / 2337973
Invention concerns metallurgy field, foundry. Particularly it concerns control modes of grey and high-duty cast iron and can be used at single-piece, large-scale and mass production of cast iron castings. In method there is received basic alloy of cast iron with usage of alloying, modifying and graphitising admixtures, process qualities are controlled and corrected including operation by effect of spheroidising and vermiculising modification at the section of casting mold charging. It is implemented one-time ladleman cast iron treatment, making preliminary calculation the quantity of alloying, modifying and graphitising admixtures depending on weight of liquid metal, containing of sulphur and oxygen, basic elements and alloying inside of basic cast iron melt and time of holding modifying effect, at that control of all process parameters is outfitted by overall video surveillance system for manufacturing operations with registration and delivering of received results into computer data base and to the lighting panel. Finishing of modifying effect is alerted by acoustic alarm.
 Ligature for modification of high-strength cast irons, method of its receiving and usage / 2355803
Invention relates to metallurgy field, particularly to magnesium-bearing ligature making practice for high-strength ligatures, used for manufacturing of hard part, for instance automobile crankshaft. Ligature contains, wt %: magnesium 17-20, cerium 0.4-0.6, copper is the rest. In the method in the capacity of integumentary flux it is used powdered baric flux, which is charged on magnesium, copper is fractional introduced: at first 60-70 wt % of its total amount, and then - by 10 wt % by components melting with addition of flux for saving of melt blanket, process is implemented at the temperature 725-800°C, chosen on the basis of binary constitution diagram Mg-Cu, during 40-60 min with conclusive layer induction of refining flux of thickness 1-2 cm and introduction of cerium with solid subsurface mixing of received ligature. Then ligature is crushed for pieces 2-4 kg, after what it is introduced into the cast iron in amount 0.65-0.85 wt % of cast iron weight.
|
FIELD: metallurgy. SUBSTANCE: cast iron melt is processed in the mould by feeding modifying mix. The latter contains a spheroidising additive composed of ferromagnesium silicon and graphitising additive composed of boric acid. Said additives are added in amounts that allows obtaining 0.03-0.06% of residual magnesium and 0.005-0.007% of boron in finished casting. Then, spontaneous annealing of casting is performed in the mould for 60 minutes. EFFECT: higher toughness at negative temperatures and process efficiency. 2 tbl
The invention relates to the field of metallurgy, in particular to a method for cold-resistant high-strength cast iron during the production of castings in the conditions of mass production. Known for high strength cast iron [1] brand VC (GOST 7293-85), which has a higher impact strength compared to cast iron higher grades. Recommended chemical composition of cast iron for castings with wall thickness up to 100 mm includes, wt.%:
Iron and impurities, and the rest. As impurities in the iron contains, wt%: phosphorus 0.05, sulfur 0.02, chromium, up to 0.1. Spheroidizing of graphite is carried out usually by treating the liquid iron magnesium-containing additives or complex modifiers. As heat treatment - Territoire annealing at 680-800°C. The disadvantage of this iron is low impact strength. Also known ductile iron [2], whose production is standard modification in 2 stages. Annealing is not applied. The disadvantage of this iron is a sharp drop in shock at what Scotti at low temperatures (from -40°C and below) more than 2 times. Closest to the proposed iron and method for obtaining a cast iron [3]. The chemical composition specified in table 1. The technology of obtaining of cast iron is that the melt is treated in 50-kg buckets by adding the modifier ligatures (of 0.8% Ni-Mg) and the adsorption-active additives (CA+CE) with a secondary modification of 0.6-0.8% ferrosilicon FS; also performed heat treatment - annealing regime: heating to 760°C, holding for 6 hours, cooled from the oven. The disadvantage of this iron are low toughness values at low temperatures (table 2). The disadvantage of this method is the long time heat treatment, which increases the time of making castings which in turn is unacceptable in terms of mass production. The technical objective of this invention is to improve the impact strength cold-resistant cast iron at subzero temperatures while reducing the time of production of castings in the conditions of mass production. The technical result is achieved by the fact that the inoculation is carried out in a mold by filing a modifier mixtures containing spheroidizing additive in the form of ferrosilicomanganese and standard additive in the form of boric acid, the quantity, ensure the receipt of finished castings 0,03-0,06% residual magnesium and 0005-0,007% boron, further samatiga castings in a mold for 60 minutes Changes in the chemical composition of pig iron introduced to a stable maximum ferritization patterns of iron castings and provide the necessary properties of the cast iron after heat treatment. With decreasing carbon content increases the amount of perlite, remaining after annealing. In this case, probably also the presence of structural free cementite and graphite are not spherical in shape. Therefore, it is necessary to have a high carbon content (3,6-3,9%), to provide better casting properties and at the same time not reduce the mechanical properties. From the point of view of plasticity, the best is the silicon content in the pig iron in the range of 2.4-2.7 percent. In order to avoid negative influence on the impact strength and to reduce the threshold jednoralski its content should not exceed 2.8 percent. Manganese has an effect opposite to the effect of silicon, reducing the amount of ferrite and increasing the amount of perlite, therefore, with the aim of reducing the threshold jednoralski, its content should not exceed 0.3%. The increase in the content of phosphorus to 0.25-0.3% causes a decrease in the plastic properties, the tensile strength decreases as the hardness increases. To obtain a high toughness, the upper limit of the content is of phosphorus should be limited to 0.05%. The content of magnesium is recommended within 0,03-0,06%. If the residual magnesium content less than 0.03%, the results of the modification unstable. The increase in magnesium content than 0.06% impractical because it does not improve the properties of cast iron. Additionally, the composition of iron introduced boron in amounts of from 0.005 to 0.007%. Together with the complex modifier, boron has an effect on the crystallization of high-strength cast iron, leading to a significant grinding grains and the stability of the austenite to the collapse of supercooling. Also boron has a high reactivity with respect to oxygen and nitrogen. Higher boron content (>0,01%) leads to orbitastarmedia effect, and reduction in plastic characteristics and the low boron content (<0.002 per cent) does not have alloy no effect (table 2). Cast iron is smelted in a crucible furnaces, providing effective melting of the charge and overheating of the melt before it is released to the temperature 1500-1550°C. Then, the molten metal transfer ladle is served in the channel mixer, where the mixing of metal and averaging its chemical composition and temperature. Further, the metal temperature 1450-1490°C is poured into the pouring ladle, which is pouring liquid metal. As the charge materials used in the comfort of steel scrap, the return of own production (gates, profit) ductile iron, ferrosilicon, graphite crushed. To obtain in the finished castings 0,03-0,06% residual magnesium, the estimated amount of the modifier is 0.8-1.2% of the metal mold. To obtain in the finished castings 0,005-0,007% boron estimated amount of boric acid is 0.06-0.08% of the metal mold. Cast-in form is poured at a temperature of 1380-1420°C. The knockout castings from moulds were made after 60 minutes Mechanical properties of cast iron was determined on samples cut directly from castings. The shape and size of samples for mechanical tests meet the requirements of relevant standards. Cast iron structure is determined on the samples subjected to mechanical testing, the side opposite to the plane of the gap. The chemical composition is known and offer cast iron are given in table 1, and the mechanical properties in table 2. It is seen that the proposed combination of the chemical composition of pig iron, method thereof and method of heat treatment provides compared to the prototype significantly higher toughness values, including at subzero temperatures. When the content of boron for the proposed limits (var, 4) properties of cast iron are significantly worse. is tkanina in the input method modifiers from claim 2 of the invention leads to reduced absorption of boron, which in turn leads to the reduction of mechanical properties (var, 6). The deviation of the method of thermal processing from claim 3 of the invention (i.e. reducing the time of samatiga) also leads to the reduction of mechanical properties of cast iron (var), however, the increase in the time samatiga not led to significant improvements (var)that is not appropriate. As follows from table 2, the claimed invention allows to increase compared with the known iron impact strength: 4-6% at +20°C, 6-10% at -20°C, 6-14% at -40°C, at 20-26% at -60°C.
1. Sherman, A.D., A.A. Zhukov Cast: Ref, ed. M.: metallurgy, 1991. - 576 pages 2. Yakovlev M.I., Petrov E.S., A.D. Andreev Cold-resistant cast iron with spherical graphite. Foundry, No. 3, 2001. P6-7. 3. Alexandrov, N.N. and other Increase of brittle fracture ductile iron. Foundry, No. 1, 1981. P.4-5. The method of producing castings from cold-cast iron, including the production of pig iron, the melt processing of modifying a mixture containing spheroidizing and standard additives, followed by heat treatment of castings, characterized in that the melt processing of iron carried out in a mold by filing a modifier mixtures containing spheroidizing additive in the form of ferrosilicomanganese and standard additive in the form of the born the th acid, the quantity, ensure the receipt of finished castings 0,03-0,06% residual magnesium and 0,005-0,007% boron, with the further samatiga castings in a mold for 60 minutes
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
