CN110592487B - 700 MPa-grade austenite ferrite dual-phase low-density cast steel and preparation method thereof - Google Patents
700 MPa-grade austenite ferrite dual-phase low-density cast steel and preparation method thereof Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
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Abstract
The invention belongs to the technical field of metal materials and metallurgy, and particularly relates to 700 MPa-grade austenite ferrite dual-phase low-density cast steel and a preparation method thereof. The invention aims to solve the technical problem of providing 700 MPa-grade austenite ferrite dual-phase low-density cast steel. The cast steel comprises the following chemical components in percentage by mass: 0.01-1.0% of C, 0.1-0.2% of Si, 10.0-25.0% of Mn, 10.0-15.0% of Al, 0.01-1.0% of V, 0.01-1.0% of Nb0.01-1.0% of Ti, less than or equal to 0.01% of S, less than or equal to 0.02% of P, and the balance of Fe and inevitable impurities; meanwhile, the weight percentage of Mn and Al is more than or equal to 25 percent and less than or equal to 35 percent; the weight percentage of Nb, V and Ti is more than or equal to 0.05 percent and less than or equal to 0.5 percent. The product of the invention has good mechanical property.
Description
Technical Field
The invention belongs to the technical field of metal materials and metallurgy, and particularly relates to 700 MPa-grade austenite ferrite dual-phase low-density cast steel and a preparation method thereof.
Background
From the viewpoint of material selection, the current automobile lightweight approach mainly comprises two approaches: one is to use light materials, such as low-density aluminum and aluminum alloys, magnesium and magnesium alloys, engineering plastics, etc., but the application of such light materials in automobile stress and load bearing parts is severely limited due to the low strength of the light materials. And secondly, the ultrahigh-strength steel is used for replacing the traditional steel, the thickness of the steel plate is reduced to reduce the weight of the vehicle body, but the high-strength steel plate is easy to rebound after being formed, the rebound quantity is far greater than that of the traditional low-carbon steel plate, and the material characteristics are complex and difficult to control. Therefore, a preparation process of low-density steel which is simple and low in cost and has both low density and high strength and plasticity is urgently needed.
Patent document CN107841691A discloses a 750MPa grade ultrahigh strength Fe-Mn-Al-C series light cast steel and a preparation method thereof, wherein the light cast steel comprises the following chemical components in percentage by weight: 0.60-1.50% of C, 10.00-14.00% of Mn10.00, 6.50-12.00% of Al0.50-1.50% of Si, 0.15-0.55% of Ni0.15-0.45% of Cr0.15-0.45%, 0.01-0.06% of Cu0.01-0.06% of Mo: 0.10-0.60% of Fe, 0.05-0.25% of V, 0.05-0.35% of Ti, 0.01-0.08% of Nb0.001-0.010% of Ce, less than or equal to 0.008% of P, less than or equal to 0.008% of S, and the balance of Fe and inevitable impurities. The light cast steel is added with more noble elements such as nickel, molybdenum, chromium, rare earth and the like, so that the preparation cost is higher, the light cast steel is not suitable for large-scale popularization and application, and the application range in automobile light weight is limited.
Disclosure of Invention
The invention aims to solve the technical problem of providing 700 MPa-grade austenite ferrite dual-phase low-density cast steel and a preparation method thereof.
The invention provides 700 MPa-grade austenite ferrite dual-phase low-density cast steel. The cast steel comprises the following chemical components in percentage by mass: 0.01-1.0% of C, 0.1-0.2% of Si, 10.0-25.0% of Mn, 10.0-15.0% of Al, 0.01-1.0% of V, 0.01-1.0% of Nb0.01-1.0% of Ti, less than or equal to 0.01% of S, less than or equal to 0.02% of P, and the balance of Fe and inevitable impurities; meanwhile, the weight percentage of Mn and Al is more than or equal to 25 percent and less than or equal to 35 percent; the weight percentage of Nb, V and Ti is more than or equal to 0.05 percent and less than or equal to 0.5 percent.
The invention also provides a preparation method of the 700 MPa-grade austenite ferrite dual-phase low-density cast steel. The method comprises the following steps:
a. preparing materials: high-purity iron, electrolytic manganese, ferrosilicon, ferrotitanium, ferrovanadium, ferroniobium, aluminum particles and a carburant are used as raw materials, and the raw materials are proportioned according to the proportion;
b. modeling: adopting water glass sand for molding, hardening a sand mold by a carbon dioxide blowing method, then coating paint on the inner wall of the sand mold, drying, and waiting for pouring;
c. smelting: smelting the raw materials in a medium-frequency induction furnace at the normal pressure of 1500-1650 ℃;
d. pouring: tapping after the temperature in the furnace is increased to 1550-1650 ℃; after deoxidation and slag removal, pouring the alloy solution into a sand mold, and air cooling to obtain a casting;
e. and (3) heat treatment: and (3) carrying out solution treatment and aging treatment on the casting, and then carrying out air cooling to obtain the 700 MPa-grade austenite ferrite dual-phase low-density cast steel.
In the step c, the smelting is to add high-purity iron into a medium-frequency induction furnace, then heat the medium-frequency induction furnace to above 1300 ℃, add electrolytic manganese, ferrosilicon, ferrotitanium, ferrovanadium, ferroniobium, aluminum particles and carburant after the high-purity iron is completely melted down, and refine the medium-frequency induction furnace for 10min at 1500-1550 ℃ after the raw materials are completely melted down.
In the preparation method of the 700 MPa-grade austenite ferrite dual-phase low-density cast steel, in the step e, the casting is subjected to solution treatment, the solution temperature is 700-1300 ℃, the temperature is kept for 10 min-5 h, water is used as a quenching medium, and the initial temperature of the quenching medium is 10-50 ℃; and (3) carrying out aging treatment within 5 hours after quenching, wherein the aging temperature is 300-600 ℃, preserving heat for 1-10 hours, and carrying out air cooling to obtain the 700 MPa-grade austenite ferrite dual-phase low-density cast steel.
In the preparation method of the 700 MPa-grade austenite ferrite dual-phase low-density cast steel, in the step a, the recarburizing agent is any one of artificial graphite, natural graphite or coke.
In the above method for producing 700MPa grade austenite ferrite dual-phase low-density cast steel, in step a, the titanium iron is preferably titanium sponge.
The invention has the beneficial effects that:
the product of the invention effectively reduces the density of the steel by reasonably matching the contents of Al, C and Mn light elements and Nb, V, Ti and other elements, ensures the strong plasticity of the steel, and ensures that the steel has good mechanical properties, the tensile strength is more than 700MPa, and the density is less than 6.5g/cm3And the elongation after fracture is more than 30 percent. The invention has wide source of the adopted raw materials, reduces the addition amount of noble metals, and the method of the inventionThe method is simple and easy to operate, does not need forging, rolling and other processes, reduces the cost for producing the low-density steel, can be applied to important fields of automobiles, high-speed rails, aerospace and the like, and has good application prospect. The method adopts the intermediate frequency induction furnace for smelting, has strong applicability in actual production, can realize mass production, has simple operation and high production efficiency, saves energy and reduces cost. The austenite ferrite dual-phase low-density cast steel has the matrix structure of austenite and ferrite, contains a small amount of carbonitride, has high strength and plasticity while obtaining low density, has good corrosion resistance, and can be widely applied.
Drawings
FIG. 1 is an X-ray diffraction chart of the austenite ferrite dual-phase low-density cast steel obtained in example 1 of the present invention.
FIG. 2 is a phase diagram of 100 times the gold phase of the austenitic ferritic dual-phase low-density cast steel obtained in example 1 of the present invention.
Detailed Description
The raw materials and equipment used in the examples of the present invention were known products and were obtained by purchasing commercially available products.
In particular, the invention provides 700 MPa-grade austenite ferrite dual-phase low-density cast steel. The cast steel comprises the following chemical components in percentage by mass: 0.01-1.0% of C, 0.1-0.2% of Si, 10.0-25.0% of Mn, 10.0-15.0% of Al, 0.01-1.0% of V, 0.01-1.0% of Nb0.01-1.0% of Ti, less than or equal to 0.01% of S, less than or equal to 0.02% of P, and the balance of Fe and inevitable impurities; meanwhile, the weight percentage of Mn and Al is more than or equal to 25 percent and less than or equal to 35 percent; the weight percentage of Nb, V and Ti is more than or equal to 0.05 percent and less than or equal to 0.5 percent.
In the component design of the invention: the element C is an austenite stabilizing element and plays a role of solid solution strengthening. In the Fe-Mn-Al-C alloy system with higher Mn content, the chemical components of an austenite phase are unstable, the increase of the C content is beneficial to improving the mechanical property of low-density steel, and the steel density is reduced by 0.41g/cm when the C content is increased by 0.1 percent3The weight can be reduced by about 5.2 percent, and the yield strength can be increased by 30MPa to 40 MPa. Along with the increase of the content of C, the content of austenite is increased, which is beneficial to improving the strength and toughness of the steel. However, low densityThe C content of the steel cannot be too high, and the C content is too high to cause adverse effects on the welding performance and the forming performance of the steel. The C element alloyed low-density steel usually generates carbide in the heat treatment process, the size and the shape of the carbide can strongly influence the obdurability of the Fe-Mn-Al-C series low-density steel, and the nano-scale carbide uniformly distributed in a matrix has a strengthening effect and is not obvious in plasticity reduction. However, the coarse grain boundary carbides distributed in the form of a flake or a band cause brittle fracture and seriously impair the toughness of the low-density steel. Sometimes the C content should be limited in order to avoid the generation of carbide phases. The inventor controls the content of C in the invention to be 0.01-1.0% through research.
Mn is a main element of low-density steel, has the effects of expanding an austenite phase region and stabilizing austenite, can exist in a solid solution state to strengthen a matrix, can enter a cementite to replace a part of Fe atoms, and can form sulfide; mn can increase the fault energy of the low-density steel, so that dense twin crystals are generated in the deformation process of the low-density steel, and the elongation of the low-density steel is obviously improved. The steel density can be reduced by 0.0085g/cm by adding 1% of Mn into the steel3And a weight reduction effect of 0.1% was obtained. However, when the Mn content is too high, a transgranular structure is easily formed, so that the welding performance is greatly reduced, the heat conductivity is reduced, and the improvement of the comprehensive performance of the Fe-Mn-Al-C series low-density steel is not facilitated. The Mn content is designed to be between 10.0 and 25 percent.
Al is an element which is most effective in increasing the stacking fault energy of low-density steel and reducing the density, and the density of the steel can be reduced by 0.101g/cm per 1 percent of Al3The weight loss was about 1.3%. Al can narrow the austenite phase region and make A3The temperature rises. The Al has duality to the stability influence of austenite, increases the stacking fault energy, strongly inhibits martensite phase transformation, is beneficial to the formation of deformation twin crystals, and improves the strong plasticity. The high Mn content and certain Al content can obviously improve the heat deformation resistance of the steel, delay dynamic recrystallization and refine austenite grains after dynamic recrystallization. The high Al content is unfavorable for casting production, and because Al is easy to oxidize, oxide slag is easy to form during casting to block a casting opening and reduce the heat cracking resistance of weld metal. When the aluminum content in the low-density steel is less, the alloy is in a solid stateThe matrix structure is ferrite, the carbide phase is increased along with the increase of the aluminum content, the ferrite can generate lattice ordered transformation, and Fe is generated3The Al phase and the FeAl phase cause a significant decrease in the toughness of the low-density steel. The inventor designs the Al content between 10.0-15% through a large amount of test screening.
Si element can be dissolved in austenite in a solid state, so that the solid solution strengthening effect is achieved, and the yield strength and the work hardening rate of the steel are improved. Si can obviously improve the corrosion resistance of Fe-Mn-Al-C steel and is beneficial to the formation of a ferrite structure. Si can change the solubility of carbon in austenite, so the influence of Si on the mechanical properties of steel is complicated. The excessive silicon content easily deteriorates the surface quality of the steel sheet, reduces the wettability of the steel sheet, generates a large amount of scale in the hot rolling process, is difficult to pickle, deteriorates the coating ability of the steel sheet and lowers the weldability of the steel, so the Si content in the invention is controlled to 0.1-0.2%.
Nb is a typical microalloying element and mainly has the functions of grain refinement and dispersion strengthening. NbC or NbN precipitation strengthening can improve the toughness while improving the strength of the material. The Nb element can improve the strength of the steel by controlling the actual proceeding degree and proceeding manner of the austenite/ferrite transformation. The research of Fe-Mn-Al-C steel focuses on light weight application of the steel plate for the automobile, and grain refinement is a strengthening means capable of improving the ductility and toughness of the steel plate. Therefore, the addition of Nb to Fe-Mn-Al-C low-density steel is indispensable. In the invention, the content of Nb is controlled between 0.01-1.0%.
The invention also provides a preparation method of the 700 MPa-grade austenite ferrite dual-phase low-density cast steel, which comprises the following steps:
a. preparing materials: high-purity iron, electrolytic manganese, ferrosilicon, ferrotitanium, ferrovanadium, ferroniobium, aluminum particles and a carburant are used as raw materials, and the raw materials are proportioned according to the proportion; the recarburizing agent is any one of artificial graphite, natural graphite or coke;
b. modeling: adopting water glass sand for molding, hardening a sand mold by a carbon dioxide blowing method, then coating paint on the inner wall of the sand mold, drying, and waiting for pouring;
c. smelting: adding high-purity iron into a medium-frequency induction furnace, heating to above 1300 ℃, adding electrolytic manganese, ferrosilicon, ferrotitanium, ferrovanadium, ferroniobium, aluminum particles and a carburant after the high-purity iron is completely melted down, and refining at 1500-1550 ℃ for 10min after the raw materials are completely melted down.
d. Pouring: tapping after the temperature in the furnace is increased to 1550-1650 ℃; after deoxidation and slag removal, pouring the alloy solution into a sand mold, and air cooling to obtain a casting;
e. and (3) heat treatment: carrying out solid solution treatment on the casting, wherein the solid solution temperature is 700-1300 ℃, the temperature is kept for 10 min-5 h, water is used as a quenching medium, and the initial temperature of the quenching medium is 10-50 ℃; and (3) carrying out aging treatment within 5 hours after quenching, wherein the aging temperature is 300-600 ℃, preserving heat for 1-10 hours, and carrying out air cooling to obtain the 700 MPa-grade austenite ferrite dual-phase low-density cast steel.
The method effectively improves the comprehensive mechanical property of the product, and leads the tensile strength of the product to be more than 700MPa and the density to be less than 6.5g/cm3And the elongation after fracture is more than 30 percent.
The present invention will be further illustrated by the following specific examples.
Selecting three alloy components according to mass percent:
the alloy comprises the following components: c: 0.82%, Mn: 18%, Si: 0.2%, V: 0.08%, Ti: 0.11%, Al: 12%, Nb: 0.12 percent;
alloy composition II: c: 0.81%, Mn: 20%, Si: 0.18%, V: 0.1%, Ti: 0.11%, Al: 11%, Nb: 0.03 percent;
alloy composition three: c: 0.85%, Mn: 22%, Si: 0.10%, V: 0.1%, Ti: 0.08%, Al: 10%, Nb: 0.05 percent.
The method is characterized in that high-purity iron, electrolytic manganese, ferrosilicon, sponge titanium, ferrovanadium, ferroniobium, aluminum particles and a carburant are used as raw materials, the material quality of each intermediate alloy is shown in table 1, an austenite ferrite low-density steel ingot is prepared through the smelting step, and the structure and the mechanical property of the material are detected and analyzed after heat treatment.
Example 1
Preparing materials: according to the target component C: 0.82%, Mn: 18%, Si: 0.2%, V: 0.08%, Ti: 0.11%, Al: 12%, Nb: the mass of each material was calculated at 0.12% mass. Bulk furnace charges such as high-purity iron and the like are weighed by adopting a 100kg electronic scale, furnace charges with small quantity of carburant, ferroniobium and ferrovanadium are weighed by adopting a 200g electronic scale, before the furnace charges are weighed, the furnace charges are polished by using a grinding wheel, surface oxide skin of the furnace charges is removed, drying treatment is carried out, and 100kg of materials are mixed in each furnace.
TABLE 1 intermediate alloy Material Single (unit wt%)
| Mn | Si | Ti | V | Nb | C | S | P | Al | |
| High purity iron | 0.04 | 0.012 | 0 | 0 | 0 | 0.003 | 0.005 | 0.004 | 0 |
| Electrolytic manganese | 99.58 | 0.015 | 0 | 0 | 0 | 0 | 0.100 | 0.010 | 0 |
| Silicon iron | 0 | 72.10 | 0 | 0 | 0 | 0.100 | 0.016 | 0.034 | 1.50 |
| Titanium sponge | 0 | 0.06 | 99.3 | 0 | 0 | 0 | 0.010 | 0.050 | 0 |
| Vanadium iron | 0.29 | 1.76 | 0 | 49.35 | 0 | 0.330 | 0.001 | 0.045 | 0.50 |
| Ferrocolumbium | 0 | 2.81 | 0 | 0 | 65.50 | 0.100 | 0.060 | 0.190 | 0.42 |
| Aluminum particles | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 99.80 |
| Carburant | 0 | 0 | 0 | 0 | 0 | 97.50 | 0 | 0 | 0 |
Modeling: the water glass sand is used for molding, and the sand formulation is shown in table 2. Before molding, sand is firstly mixed in a dry mode and then mixed in a wet mode, the adding amount of water glass is controlled in the sand mixing process, and unnecessary waste is prevented under the condition that the strength of a sand mold is guaranteed. Then the mould is used for moulding, after the mould is made, a plurality of uniform air holes are punched on the mould, and the sand mould is hardened by blowing carbon dioxide. And after the sand mold is completely hardened, taking out the mold, and finally coating a refractory material for pouring.
TABLE 2 formulation of molding materials
| Molding material | Proportioning (wt%) | Performance parameter |
| Quartz sand (New sand) | 93.5 | 40-70 mesh |
| Water glass | 6.5 | Modulus M2.1-2.6 |
Smelting: firstly, adding high-purity iron into a medium-frequency induction furnace, checking the safety of the electric furnace, then transmitting power to enter a smelting stage, adding alloy materials (electrolytic manganese, ferrosilicon, sponge titanium, ferrovanadium, ferroniobium, aluminum particles and carburant which are weighed in advance) after the high-purity iron is completely melted down, and entering an alloying stage. And (3) after the alloy is completely melted down, refining for 15 minutes at 1500-1550 ℃, and adjusting and replenishing alloy materials after analyzing the components of the alloy.
Pouring: after the target components are achieved, the power is increased, the temperature is increased to 1588 ℃, and then steel is tapped; and pouring the alloy solution into a sand mold, and then air-cooling to obtain a casting.
And (3) heat treatment: the heat treatment of the casting is carried out in a muffle furnace, the solution treatment is firstly carried out, the casting is put into the muffle furnace after the temperature of the muffle furnace rises to 1050 ℃ and is stabilized for 20min, the casting is taken out after the temperature is kept for 1.5 h, the casting is rapidly put into a water tank and is slowly stirred, so that the casting can be rapidly cooled, and the initial water temperature is 30 ℃. And (3) after the casting is cooled to room temperature, carrying out aging treatment within 5 hours, wherein the aging temperature is 580 ℃, after the temperature of the furnace is raised to 580 ℃, stabilizing for 20min, putting in the furnace, preserving the heat for 6 hours, taking out the furnace, and then carrying out air cooling to room temperature. Austenitic ferrite dual-phase low-density cast steel having the composition shown in example 1 in Table 3 was obtained.
As is clear from fig. 2, the cast steel obtained in this example had a matrix structure with uniform grains, and the matrix was austenite and ferrite, and carbides having a dotted distribution precipitated in the grain boundaries and the grains. Solution treatment water quenching causes the carbides to be dispersed as fine particles from a supersaturated matrix, and the dispersed carbides contribute to the improvement of the strength of the austenitic ferritic dual-phase steel. The fine and uniform austenite ferrite dual-phase matrix structure is beneficial to preventing the generation and the expansion of cracks during deformation, and the plasticity and the toughness of the steel are enhanced.
Example 2
According to the target component C: 0.81%, Mn: 20%, Si: 0.18%, V: 0.1%, Ti: 0.11%, Al: 11%, Nb: the mass of each material (high purity iron, electrolytic manganese, ferrosilicon, sponge titanium, ferrovanadium, ferroniobium, aluminum particles, carburant) was calculated at 0.03 mass%. The material preparation, modeling, smelting and pouring method is as shown in example 1, and the difference is as follows: in the heat treatment step, the casting is subjected to solid solution and heat preservation at 1000 ℃ for 2h, is cooled to room temperature by water, is subjected to aging and heat preservation at 500 ℃ for 6.5h, and is cooled to room temperature by air. Austenitic ferrite dual-phase low-density cast steels having the compositions shown in example 2 in Table 3 were obtained.
Example 3
According to the target component C: 0.85%, Mn: 22%, Si: 0.10%, V: 0.1%, Ti: 0.08%, Al: 10%, Nb: the mass of each material (high purity iron, electrolytic manganese, ferrosilicon, sponge titanium, ferrovanadium, ferroniobium, aluminum particles, carburant) was calculated at 0.05 mass%. The material preparation, modeling, smelting and pouring method is as shown in example 1, and the difference is as follows: in the heat treatment step, the casting is subjected to solid solution heat preservation at 900 ℃ for 2.5h, is cooled to room temperature by water, is subjected to aging heat preservation at 450 ℃ for 7h, and is cooled to room temperature by air. Austenitic ferrite dual-phase low-density cast steels having the compositions shown in example 3 in Table 3 were obtained.
TABLE 3 Austenitic ferrite two-phase low-density cast steel prepared by the inventive example
| Examples | C | Si | Mn | Al | Nb | V | Ti | S | P |
| 1 | 0.82 | 0.15 | 18.4 | 12.1 | 0.12 | 0.11 | 0.15 | 0.0047 | 0.0057 |
| 2 | 0.80 | 0.18 | 20.3 | 11.6 | 0.03 | 0.10 | 0.10 | 0.0051 | 0.0055 |
| 3 | 0.84 | 0.11 | 22.6 | 10.2 | 0.04 | 0.09 | 0.08 | 0.0056 | 0.0061 |
A tensile test bar with the diameter of 5mm is made by a universal tensile testing machine by referring to the national standard GB/T228.1-2010, and the mechanical property of the samples of each embodiment is measured; the density of the sample of each example was measured using a precision balance. Tensile strength, elongation after fracture and density are shown in table 4.
TABLE 4 mechanical Properties results of cast steels according to the examples of the invention
| Examples | Tensile strength (MPa) | Elongation after Break (%) | Density (g/cm)3) |
| 1 | 724 | 36.12 | 6.38 |
| 2 | 735 | 35.36 | 6.42 |
| 3 | 718 | 32.51 | 6.32 |
As can be seen from Table 4, the lowest density of the 700 MPa-grade austenite ferrite dual-phase low-density cast steel obtained by the invention can be reducedTo 6.32g/cm3Compared with the common cast steel, the density is reduced by 18.97 percent, the tensile strength reaches 735MPa, the elongation after fracture reaches 32.5 percent, and the density and the ductility and toughness are better matched.
Claims (5)
1.700 MPa-grade austenite ferrite dual-phase low-density cast steel, which is characterized in that: the cast steel comprises the following chemical components in percentage by mass: 0.01-1.0% of C, 0.1-0.2% of Si, 10.0-25.0% of Mn, 10.0-15.0% of Al, 0.01-1.0% of V, 0.01-1.0% of Nb0.01-1.0% of Ti, less than or equal to 0.01% of S, less than or equal to 0.02% of P, and the balance of Fe and inevitable impurities; meanwhile, the weight percentage of Mn and Al is more than or equal to 25 percent and less than or equal to 35 percent; the weight percentage of Nb, V and Ti is more than or equal to 0.05 percent and less than or equal to 0.5 percent;
the density of the dual-phase low-density cast steel is less than or equal to 6.42g/cm3(ii) a The elongation after fracture is more than 30 percent.
2. The method for the production of austenitic ferritic dual-phase low-density cast steel of 700MPa grade according to claim 1, characterized by the following steps:
a. preparing materials: high-purity iron, electrolytic manganese, ferrosilicon, ferrotitanium, ferrovanadium, ferroniobium, aluminum particles and a carburant are used as raw materials, and the raw materials are proportioned according to the proportion;
b. modeling: adopting water glass sand for molding, hardening a sand mold by a carbon dioxide blowing method, then coating paint on the inner wall of the sand mold, drying, and waiting for pouring;
c. smelting: smelting the raw materials in a medium-frequency induction furnace at the normal pressure of 1500-1650 ℃;
d. pouring: tapping after the temperature in the furnace is increased to 1550-1650 ℃; after deoxidation and slag removal, pouring the alloy solution into a sand mold, and air cooling to obtain a casting;
e. and (3) heat treatment: and (3) carrying out solution treatment and aging treatment on the casting, and then carrying out air cooling to obtain the 700 MPa-grade austenite ferrite dual-phase low-density cast steel.
3. The method for the production of a 700MPa grade austenitic ferritic dual-phase low-density cast steel according to claim 2, characterized in that: in the step c, the smelting is to add high-purity iron into the medium-frequency induction furnace, then heat the medium-frequency induction furnace to above 1300 ℃, add electrolytic manganese, ferrosilicon, ferrotitanium, ferrovanadium, ferroniobium, aluminum particles and carburant after the high-purity iron is completely melted down, and refine the medium-frequency induction furnace for 10min at 1500-1550 ℃ after the raw materials are completely melted down.
4. The method for the production of a 700MPa grade austenitic ferrite dual-phase low-density cast steel according to claim 2 or 3, characterized in that: step e, carrying out solid solution treatment on the casting, wherein the solid solution temperature is 700-1300 ℃, the temperature is kept for 10 min-5 h, water is used as a quenching medium, and the initial temperature of the quenching medium is 10-50 ℃; and (3) carrying out aging treatment within 5 hours after quenching, wherein the aging temperature is 300-600 ℃, preserving heat for 1-10 hours, and carrying out air cooling to obtain the 700 MPa-grade austenite ferrite dual-phase low-density cast steel.
5. The method for the production of a 700MPa grade austenitic ferritic dual-phase low-density cast steel according to claim 2, characterized in that: in the step a, the recarburizing agent is any one of artificial graphite, natural graphite or coke.
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| CN111607740A (en) * | 2020-06-24 | 2020-09-01 | 安徽工业大学 | Preparation method of high-strength low-density steel and high-strength low-density steel |
| CN113278894A (en) * | 2021-05-20 | 2021-08-20 | 成都先进金属材料产业技术研究院股份有限公司 | Fe-Mn-Al-S series low-density free-cutting steel and preparation method thereof |
| CN113832408A (en) * | 2021-10-19 | 2021-12-24 | 成都先进金属材料产业技术研究院股份有限公司 | Fe-15Mn-8Al-0.3C ferrite-austenite dual-phase low-density steel and heat treatment method thereof |
| CN115323278A (en) * | 2022-06-29 | 2022-11-11 | 钢铁研究总院有限公司 | Low-density steel with yield of 700MPa and heat treatment method thereof |
| CN115896611B (en) * | 2022-10-28 | 2024-01-12 | 鞍钢集团矿业有限公司 | Austenite-ferrite dual-phase heat-resistant steel and preparation method and application thereof |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103820735A (en) * | 2014-02-27 | 2014-05-28 | 北京交通大学 | Super strength C-Al-Mn-Si series low-density steel and its preparation method |
| CN104350169B (en) * | 2012-05-31 | 2017-02-22 | 安赛乐米塔尔研发有限公司 | Low-density hot- or cold-rolled steel, method for implementing same and use thereof |
| CN106521318A (en) * | 2016-11-22 | 2017-03-22 | 河北工业大学 | High-strength Fe-Mn-Al-C-series low density cast steel and preparation method thereof |
| CN107841691A (en) * | 2017-10-25 | 2018-03-27 | 河北工业大学 | A kind of 750MPa grade super strengths Fe Mn Al C systems lightweight cast steel and preparation method thereof |
| CN108642403A (en) * | 2018-05-28 | 2018-10-12 | 河北工业大学 | A kind of 780MPa grade super strengths Fe-Mn-Al-C systems lightweight cast steel and preparation method thereof |
-
2019
- 2019-10-22 CN CN201911005087.0A patent/CN110592487B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104350169B (en) * | 2012-05-31 | 2017-02-22 | 安赛乐米塔尔研发有限公司 | Low-density hot- or cold-rolled steel, method for implementing same and use thereof |
| CN103820735A (en) * | 2014-02-27 | 2014-05-28 | 北京交通大学 | Super strength C-Al-Mn-Si series low-density steel and its preparation method |
| CN106521318A (en) * | 2016-11-22 | 2017-03-22 | 河北工业大学 | High-strength Fe-Mn-Al-C-series low density cast steel and preparation method thereof |
| CN107841691A (en) * | 2017-10-25 | 2018-03-27 | 河北工业大学 | A kind of 750MPa grade super strengths Fe Mn Al C systems lightweight cast steel and preparation method thereof |
| CN108642403A (en) * | 2018-05-28 | 2018-10-12 | 河北工业大学 | A kind of 780MPa grade super strengths Fe-Mn-Al-C systems lightweight cast steel and preparation method thereof |
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