CN114703429B - Fe-Mn-Al-C series austenitic light steel and preparation method thereof - Google Patents
Fe-Mn-Al-C series austenitic light steel and preparation method thereof Download PDFInfo
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- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
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- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
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- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
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- C21D2211/001—Austenite
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Abstract
The invention provides Fe-Mn-Al-C series austenitic light steel and a preparation method thereof, and relates to the technical field of alloy materials. The Fe-Mn-Al-C series austenitic light steel provided by the invention comprises the following elements in percentage by mass: 1.2-1.4% of C, 9-11% of Al, 25-30% of Mn and the balance of Fe. The Fe-Mn-Al-C series austenitic light steel provided by the invention not only reduces the density, but also improves the strength. The density of the Fe-Mn-Al-C series austenitic light steel provided by the invention is 6.62g/cm 3 The iron content is reduced by 16.10 percent compared with pure iron; the Fe-Mn-Al-C series austenitic light steel has excellent comprehensive mechanical properties, wherein the tensile strength is 1387-1512 MPa, and the yield strength is 1170-1428 MPa, so that the safety performance of the material in the use process is ensured.
Description
Technical Field
The invention relates to the technical field of alloy materials, in particular to Fe-Mn-Al-C austenite lightweight steel and a preparation method thereof.
Background
Steel materials have taken an important position in various industries as alloy materials which are most widely applied. However, the weight of the steel becomes the bottleneck of further wide application in industry and life, and with the rapid development of lighter titanium, aluminum alloy and the like, great challenges are brought to the steel industry, so that the light weight of steel is paid great attention.
In recent years, many researchers have conducted intensive research on Fe-Mn-Al-C light steel and successfully applied the light steel in a plurality of industries, such as automobiles, ocean engineering, metallurgy, chemical engineering, light industry and the like, wherein the light steel is most prominently used in the automobile industry. The Fe-Mn-Al-C based lightweight steel has a lower density than the conventional steel materials, but its strength is to be further improved.
Disclosure of Invention
The invention aims to provide Fe-Mn-Al-C austenite light steel and a preparation method thereof.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides Fe-Mn-Al-C austenite lightweight steel, which comprises the following elements in percentage by mass: 1.2-1.4% of C, 9-11% of Al, 25-30% of Mn and the balance of Fe.
Preferably, the microstructure of the Fe-Mn-Al-C system austenitic light steel includes small recrystallized austenite grains and flat unrecrystallized austenite grains; the size of the recrystallized austenite small crystal grains is 2-4 mu m; the size of the flat unrecrystallized austenite grains is 30 to 40 μm.
Preferably, the volume content of the recrystallized austenite small grains is 8-10%; the volume content of the flat unrecrystallized austenite grains is 90-92%.
The invention provides a preparation method of Fe-Mn-Al-C austenite lightweight steel in the technical scheme, which comprises the following steps:
smelting a metal raw material to obtain an alloy ingot; the composition of the metal raw material is consistent with the element composition of the Fe-Mn-Al-C system austenite lightweight steel in the technical scheme;
carrying out hot forging treatment on the alloy cast ingot to obtain an alloy forging material;
homogenizing the alloy forging stock to obtain a uniform alloy forging stock;
carrying out hot rolling treatment on the uniform chemical combination gold forging material to obtain a hot-rolled alloy plate blank;
performing cold rolling treatment on the hot-rolled alloy plate blank to obtain a cold-rolled alloy plate blank;
annealing the cold-rolled alloy plate blank to obtain Fe-Mn-Al-C series austenitic light steel; the temperature of the annealing treatment is 800-900 ℃, and the heat preservation time of the annealing treatment is 3-15 min.
Preferably, the temperature of the hot forging treatment is 1125-1180 ℃; the hot forging treatment is multi-pass forging.
Preferably, the temperature of the homogenization treatment is 1150-1200 ℃, the heat preservation time of the homogenization treatment is 120-180 min, and the homogenization treatment is followed by water cooling to room temperature.
Preferably, the temperature of the hot rolling treatment is 950-1100 ℃; the hot rolling treatment is multi-pass hot rolling deformation, and the reduction of each pass is not more than 20%; the total deformation amount of the hot rolling treatment is 80-85%.
Preferably, the hot rolling treatment is completed and then water quenched to room temperature.
Preferably, the cold rolling treatment is performed at room temperature; the cold rolling treatment is multi-pass rolling deformation, and the reduction of each pass is not more than 5%; the total deformation amount of the cold rolling treatment is 30-40%.
Preferably, the annealing treatment further comprises: carrying out aging treatment on the obtained annealed cold-rolled alloy plate blank to obtain Fe-Mn-Al-C series austenite light steel;
the temperature of the aging treatment is 500-600 ℃; the heat preservation time of the aging treatment is 10-60 min.
The invention provides Fe-Mn-Al-C austenite lightweight steel, which comprises the following elements in percentage by mass: 1.2-1.4% of C, 9-11% of Al, 25-30% of Mn and the balance of Fe. The Al element is added into the Fe-Mn-Al-C light steel, so that the density of the steel can be reduced, and the density of the steel is reduced because the density of Al atoms is far lower than that of Fe atoms and a part of Al atoms are used for replacing Fe atoms; in addition, the addition of Al causes lattice expansion, so that the volume of the lightweight steel is increased, and the density is further reduced. Element CThe addition of the Fe-Mn-Al-C alloy can improve the stability of austenite in steel and the recovery power of the austenite, expand an austenite phase region and have a gap solid solution strengthening effect, thereby improving the toughness of Fe-Mn-Al-C light steel and improving the wear resistance of the steel by solid solution in the austenite. The addition of Mn element can enlarge the austenite phase region, so that austenite stability is increased, and can exist stably at room temperature, and in addition, Mn atom has a solid solution strengthening effect. In the present invention, each element contributes to the density of the lightweight steel in such a way that the density of the steel decreases by 0.101g/cm per 1% by mass of Al added 3 The weight can be reduced by 1.3%; the density of the steel is reduced by 0.41g/cm per 1% C addition 3 The weight can be reduced by 5.2 percent; the density of the steel is reduced by 0.0085g/cm per 1% of Mn added 3 The weight can be reduced by 0.1%.
According to the invention, high-quality-percentage Al and C elements are added into the lightweight steel, so that the alloy is subjected to amplitude modulation decomposition in the aging treatment process to generate a nano-grade kappa-carbide with the size of 1-20 nm and the molecular formula of (Fe, Mn) 3 AlC x (x < 1), which will keep a high degree of compatibility with austenite, and improve the strong plasticity of the alloy.
The Fe-Mn-Al-C series austenitic light steel provided by the invention not only reduces the density, but also improves the strength. The density of the Fe-Mn-Al-C series austenitic light steel provided by the invention is 6.62g/cm 3 Compared with pure iron, the iron content is reduced by 16.10%, and the iron is significant for reducing energy consumption when used as a delivery vehicle; the Fe-Mn-Al-C series austenitic light steel has excellent comprehensive mechanical properties, wherein the tensile strength is 1387-1512 MPa, and the yield strength is 1170-1428 MPa, so that the safety performance of the material in the use process is ensured.
The invention also provides a preparation method of the Fe-Mn-Al-C austenite light steel in the technical scheme, and the Fe-Mn-Al-C austenite light steel prepared by the invention has the advantages of low price, simple preparation process and cost saving; easy to machine and form, and can be widely applied. Compared with the traditional heat treatment process of other light steel plates, the invention provides an optimized heat treatment means, and the Fe-Mn-Al-C austenite light steel realizes ultrahigh strength by regulating and controlling the alloy microstructure.
Drawings
FIG. 1 is a schematic drawing of dimensions of a tensile specimen, wherein the dimensions are in mm;
FIG. 2 is an electron back-scattering diffraction pattern of an Fe-Mn-Al-C system austenitic light steel prepared in example 1;
FIG. 3 is an electron back-scattering diffraction pattern of an Fe-Mn-Al-C system austenitic light steel produced in example 2;
FIG. 4 is an electron back-scattering diffraction pattern of an Fe-Mn-Al-C system austenitic light steel prepared in example 3;
FIG. 5 is a TEM image of kappa-carbides in an Fe-Mn-Al-C system austenitic light steel prepared in example 3, wherein (a) is a bright field image; (b) a dark field image; (c) are diffraction spots.
Detailed Description
The invention provides Fe-Mn-Al-C austenite lightweight steel, which comprises the following elements in percentage by mass: 1.2-1.4% of C, 9-11% of Al, 25-30% of Mn and the balance of Fe. In the present invention, the Fe-Mn-Al-C system austenitic light steel preferably comprises: 1.3% of C, 10% of Al, 26-27% of Mn and the balance of Fe.
In the present invention, the Fe-Mn-Al-C system austenitic light steel further includes unavoidable impurity elements.
In the present invention, the microstructure of the Fe-Mn-Al-C system austenitic light steel preferably includes small recrystallized austenite grains and flat unrecrystallized austenite grains; the size of the recrystallized austenite small crystal grains is preferably 2-4 mu m; the size of the flat unrecrystallized austenite grains is preferably 30 to 40 μm. In the invention, the volume content of the recrystallized austenite small crystal grains is preferably 8-10%; the volume content of the flat unrecrystallized austenite grains is preferably 90-92%.
The invention also provides a preparation method of the Fe-Mn-Al-C austenite light steel in the technical scheme, which comprises the following steps:
smelting a metal raw material to obtain an alloy ingot; the composition of the metal raw material is consistent with the element composition of the Fe-Mn-Al-C system austenite lightweight steel in the technical scheme;
carrying out hot forging treatment on the alloy cast ingot to obtain an alloy forging material;
homogenizing the alloy forging stock to obtain a uniform alloy forging stock;
carrying out hot rolling treatment on the uniform chemical combination gold forging material to obtain a hot-rolled alloy plate blank;
performing cold rolling treatment on the hot-rolled alloy plate blank to obtain a cold-rolled alloy plate blank;
annealing the cold-rolled alloy plate blank to obtain Fe-Mn-Al-C series austenite light steel; the temperature of the annealing treatment is 800-900 ℃, and the heat preservation time of the annealing treatment is 3-15 min.
The method provided by the invention is used for smelting metal raw materials to obtain alloy ingots. In the present invention, the metal raw material preferably includes a high purity iron rod, an electrolytic manganese flake, a high purity aluminum rod, and a high purity carbon. In the invention, before smelting, the metal raw material preferably further comprises pretreatment; the pretreatment preferably comprises washing and air-drying in sequence. In the present invention, the washing liquid for washing is preferably alcohol; the cleaning is preferably ultrasonic cleaning.
In the present invention, the composition of the metal raw material is in accordance with the elemental composition of the Fe-Mn-Al-C system austenitic light steel described in the above technical means. In the present invention, the melting is preferably vacuum induction melting.
In the invention, because the added carbon has low mass percentage and density and is easy to lose, in order to accurately control the content of alloy components, the iron, the manganese and the aluminum with high density are firstly added into a crucible for smelting, carbon is added after molten steel is molten down, and the molten steel is continuously molten down to finally obtain the molten steel meeting the component ratio.
After the smelting, the obtained molten steel is preferably poured into a mold and naturally cooled to room temperature to obtain an alloy ingot.
After the alloy cast ingot is obtained, the alloy cast ingot is subjected to hot forging treatment to obtain the alloy forging material. In the invention, the temperature of the hot forging treatment is preferably 1125-1180 ℃, and more preferably 1140 ℃; the hot forging treatment is preferably multi-pass forging. In the present invention, the rate of temperature increase from room temperature to the temperature of the hot forging treatment is preferably 10 ℃/min.
After the alloy forging stock is obtained, the alloy forging stock is subjected to homogenization treatment to obtain a uniform alloy forging stock. In the invention, the temperature of the homogenization treatment is preferably 1150-1200 ℃, the heat preservation time of the homogenization treatment is preferably 120-180 min, and the homogenization treatment is followed by water cooling to room temperature.
After the uniform alloy forging stock is obtained, the uniform alloy forging stock is subjected to hot rolling treatment to obtain a hot-rolled alloy plate blank. In the invention, the temperature of the hot rolling treatment is preferably 950-1100 ℃; the hot rolling treatment is preferably multi-pass hot rolling deformation, and the reduction of each pass is preferably not more than 20%; the total deformation amount of the hot rolling treatment is preferably 80-85%. In the present invention, it is preferable to water-quench the steel sheet to room temperature after the hot rolling treatment. The hot rolling process can prevent rolling cracking. In the present invention, the rate of temperature increase from room temperature to the temperature of the hot rolling treatment is preferably 10 ℃/min.
After the hot-rolled alloy slab is obtained, the cold-rolled alloy slab is subjected to cold rolling treatment to obtain the cold-rolled alloy slab. In the present invention, the cold rolling treatment is preferably performed at room temperature; the cold rolling treatment is preferably multi-pass rolling deformation, and the reduction of each pass is preferably not more than 5%; the total deformation amount of the cold rolling treatment is preferably 30-40%, and more preferably 35%. The cold rolling process can prevent rolling cracking.
After the cold-rolled alloy plate blank is obtained, the cold-rolled alloy plate blank is annealed to obtain the Fe-Mn-Al-C series austenite light steel. In the invention, the annealing temperature is 800-900 ℃, preferably 850 ℃; and the heat preservation time of the annealing treatment is 3-15 min. The annealing process can enable the alloy to have a two-state microstructure, namely recrystallized austenite grains and unrecrystallized austenite grains, and improve the strength of the alloy.
In the present invention, it is preferable that the annealing treatment further includes: and carrying out aging treatment on the obtained annealed cold-rolled alloy plate blank to obtain the Fe-Mn-Al-C series austenite lightweight steel. According to the invention, preferably, after the annealing treatment, water quenching is carried out to room temperature to obtain the annealed cold-rolled alloy plate blank.
In the invention, the temperature of the aging treatment is preferably 500-600 ℃, and more preferably 550 ℃; the heat preservation time of the aging treatment is preferably 10-60 min, and more preferably 20-40 min. In the present invention, when the effective temperature is 500 to 600 ℃, there is little influence on the volume fraction and grain size of the partially recrystallized microstructure because the lower temperature is insufficient to provide kinetics of grain recovery and growth.
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
According to the mass percentage, the metal raw materials are as follows: 1.2% of carbon, 27% of manganese, 10% of aluminum and the balance of an iron rod with the diameter of 25 mm.
After the raw materials are subjected to ultrasonic cleaning treatment in alcohol, putting manganese and iron in the raw materials into a magnesia crucible in a vacuum induction furnace, and putting aluminum and carbon in the raw materials into a secondary hopper of the vacuum induction furnace; vacuumizing the vacuum induction furnace to the vacuum degree of 0.02MPa, and then filling high-purity argon into the vacuum induction furnace to the vacuum degree of 0.03 MPa; setting the power of the vacuum induction furnace to 5kW, and heating for 6 min; setting the power of the vacuum induction furnace to 10kW, and heating for 6 min; setting the power of the vacuum induction furnace to be 20kW, heating for 12min, and pouring the raw materials in the secondary charging hopper into a magnesia crucible; setting the power of the vacuum induction furnace to 40kW, heating for 25min to obtain molten steel, and then pouring the molten steel into a mold to naturally cool to room temperature to obtain an alloy ingot;
placing the alloy cast ingot in a muffle furnace, heating to 1140 ℃ at a heating rate of 10 ℃/min, preserving heat for 40min, forging by using a 150kg forging hammer, and forging for 5 times to obtain a round bar with the diameter of 60 mm;
and (3) placing the round bar with the diameter of 60mm in a muffle furnace at the temperature of 1150 ℃ for heat preservation for 120min, and then cooling to room temperature by water to obtain the uniform chemical combination gold forging material.
Cutting the uniform alloy forging material into steel blocks of 60mm multiplied by 20mm, then putting the steel blocks into a muffle furnace which is heated to 1050 ℃ at the heating rate of 10 ℃/min, and quickly taking out the material after heat preservation for 0.5h for first hot rolling; after rolling, putting the steel block into a muffle furnace, reheating to 1050 ℃, preserving heat for 5min, carrying out second hot rolling, repeating the operation for 6 times, and obtaining a hot rolling treatment product with the thickness of 3mm, wherein the total deformation of the hot rolling treatment is 83%; and after the final pass rolling, rapidly performing water quenching on the hot rolled plate, and taking out the hot rolled plate after cooling to normal temperature to obtain the hot rolled alloy plate blank.
And (3) carrying out cold rolling treatment on the hot-rolled alloy plate blank on a double-roller mill to obtain a cold-rolled alloy plate blank with the thickness of 2mm, wherein the total deformation of the cold rolling treatment is 33%.
And (3) putting the cold-rolled alloy plate blank into a muffle furnace at a constant temperature of 850 ℃ for heat preservation for 3min to obtain the Fe-Mn-Al-C series austenitic light steel.
FIG. 2 is an EBSD map of the Fe-Mn-Al-C system austenitic light steel produced in example 1, and from FIG. 1, it can be seen that the resulting Fe-Mn-Al-C system austenitic light steel is composed of fine austenite grains and coarse unrecrystallized austenite grains.
Example 2
According to the mass percentage, the metal raw materials are as follows: 1.2% of carbon, 27% of manganese, 10% of aluminum and the balance of an iron rod with the diameter of 25 mm.
After the raw materials are subjected to ultrasonic cleaning treatment in alcohol, putting manganese and iron in the raw materials into a magnesia crucible in a vacuum induction furnace, and putting aluminum and carbon in the raw materials into a secondary hopper of the vacuum induction furnace; vacuumizing the vacuum induction furnace to the vacuum degree of 0.02MPa, and then filling high-purity argon into the vacuum induction furnace to the vacuum degree of 0.03 MPa; setting the power of the vacuum induction furnace to 5kW, and heating for 6 min; setting the power of the vacuum induction furnace to 10kW, and heating for 6 min; setting the power of the vacuum induction furnace to be 20kW, heating for 12min, and pouring the raw materials in the secondary charging hopper into a magnesia crucible; setting the power of the vacuum induction furnace to 40kW, heating for 25min to obtain molten steel, and then pouring the molten steel into a mold to naturally cool to room temperature to obtain an alloy ingot;
placing the alloy cast ingot in a muffle furnace, heating to 1140 ℃ at a heating rate of 10 ℃/min, keeping the temperature for 40min, forging by adopting a 150kg forging hammer, and forging for 5 times to obtain a round bar with the diameter of 60 mm;
and (3) placing a round bar with the diameter of 60mm in a muffle furnace at the temperature of 1150 ℃ for heat preservation for 120min, and then cooling to room temperature by water to obtain the uniform compound gold forging material.
Cutting the uniform alloy forging material into steel blocks of 60mm multiplied by 20mm, then putting the steel blocks into a muffle furnace which is heated to 1050 ℃ at the heating rate of 10 ℃/min, and quickly taking out the material after heat preservation for 0.5h for first hot rolling; after rolling, putting the steel block into a muffle furnace, reheating to 1050 ℃, preserving heat for 5min, carrying out second hot rolling, repeating the operation for 6 times, and obtaining a hot rolling treatment product with the thickness of 3mm, wherein the total deformation of the hot rolling treatment is 83%; and after the final pass rolling, rapidly performing water quenching on the hot rolled plate, and taking out the hot rolled plate after cooling to normal temperature to obtain the hot rolled alloy plate blank.
And (3) carrying out cold rolling treatment on the hot-rolled alloy plate blank on a double-roller mill to obtain a cold-rolled alloy plate blank with the thickness of 2mm, wherein the total deformation of the cold rolling treatment is 33%.
And (3) putting the cold-rolled alloy plate blank into a muffle furnace with a constant temperature of 850 ℃, annealing, keeping the temperature for 3min, and performing water quenching to room temperature to obtain the annealed cold-rolled alloy plate blank.
And placing the annealed cold-rolled alloy plate blank into a muffle furnace at the constant temperature of 550 ℃ for aging treatment, wherein the heat preservation time is 20min, so as to obtain the Fe-Mn-Al-C series austenite light steel.
FIG. 3 is an EBSD map of the Fe-Mn-Al-C system austenitic light steel produced in example 2, and from FIG. 3, it can be seen that the resulting Fe-Mn-Al-C system austenitic light steel consists of fine austenite grains and coarse unrecrystallized austenite grains.
Example 3
According to the mass percentage, the metal raw materials are as follows: 1.2% of carbon, 27% of manganese, 10% of aluminum and the balance of an iron rod with the diameter of 25 mm.
After the raw materials are subjected to ultrasonic cleaning treatment in alcohol, putting manganese and iron in the raw materials into a magnesia crucible in a vacuum induction furnace, and putting aluminum and carbon in the raw materials into a secondary hopper of the vacuum induction furnace; vacuumizing the vacuum induction furnace to the vacuum degree of 0.02MPa, and then filling high-purity argon into the vacuum induction furnace to the vacuum degree of 0.03 MPa; setting the power of the vacuum induction furnace to 5kW, and heating for 6 min; setting the power of the vacuum induction furnace to 10kW, and heating for 6 min; setting the power of the vacuum induction furnace to be 20kW, heating for 12min, and pouring the raw materials in the secondary charging hopper into a magnesia crucible; setting the power of the vacuum induction furnace to 40kW, heating for 25min to obtain molten steel, and then pouring the molten steel into a mold to naturally cool to room temperature to obtain an alloy ingot;
placing the alloy cast ingot in a muffle furnace, heating to 1140 ℃ at a heating rate of 10 ℃/min, preserving heat for 40min, forging by using a 150kg forging hammer, and forging for 5 times to obtain a round bar with the diameter of 60 mm;
and (3) placing the round bar with the diameter of 60mm in a muffle furnace at the temperature of 1150 ℃ for heat preservation for 120min, and then cooling to room temperature by water to obtain the uniform chemical combination gold forging material.
Cutting the uniform alloy forging material into steel blocks of 60mm multiplied by 20mm, then putting the steel blocks into a muffle furnace which is heated to 1050 ℃ at the heating rate of 10 ℃/min, and quickly taking out the material after heat preservation for 0.5h for first hot rolling; after rolling, placing the steel block into a muffle furnace, reheating to 1050 ℃, preserving heat for 5min, performing second hot rolling, repeating the operation for 6 times to obtain a hot rolling treatment product with the thickness of 3mm, wherein the total deformation of the hot rolling treatment is 83%; and after the final pass rolling, rapidly performing water quenching on the hot rolled plate, and taking out the hot rolled plate after cooling to normal temperature to obtain the hot rolled alloy plate blank.
And (3) carrying out cold rolling treatment on the hot-rolled alloy plate blank on a double-roller mill to obtain a cold-rolled alloy plate blank with the thickness of 2mm, wherein the total deformation of the cold rolling treatment is 33%.
And (3) putting the cold-rolled alloy plate blank into a muffle furnace with a constant temperature of 850 ℃, annealing, keeping the temperature for 3min, and performing water quenching to room temperature to obtain the annealed cold-rolled alloy plate blank.
And placing the annealed cold-rolled alloy plate blank into a muffle furnace with the constant temperature of 550 ℃ for aging treatment, wherein the heat preservation time is 60min, and obtaining the Fe-Mn-Al-C series austenite light steel.
FIG. 4 is an EBSD map of the Fe-Mn-Al-C system austenitic light steel produced in example 3, and from FIG. 4, it can be seen that the resulting Fe-Mn-Al-C system austenitic light steel consists of fine austenite grains and coarse unrecrystallized austenite grains.
FIG. 5 is a TEM image of kappa-carbides in Fe-Mn-Al-C system austenitic light steel prepared in example 3, and FIG. 5 (a) is a bright field image; (b) a dark field image; (c) is electron diffraction.
Comparative example 1
Z.Q.Wu,H.Ding,X.H.An,D.Han,X.Z.Liao,Influence ofAl content on the strain-hardening behavior of aged lowdensity Fe–Mn–Al–C steels with high Al content,Mater.Sci.Eng.A 639(2015)187-191.
Comparative example 2
Z.Q.Wu,H.Ding,X.H.An,D.Han,X.Z.Liao,Influence ofAl content on the strain-hardening behavior of aged lowdensity Fe–Mn–Al–C steels with high Al content,Mater.Sci.Eng.A 639(2015)187-191.
Comparative example 3
L.L.Wei,G.H.Gao,J.Kim,R.D.K.Misra,C.G.Yang,X.J.Jin,Ultrahigh strength-high ductility 1GPa low density austenitic steel with ordered precipitation strengthening phase and dynamic slip band refnement,Mater.Sci.Eng.A.838(2022)142829.
Test example
According to GB/T228-.
TABLE 1 mechanical properties of examples 1 to 3 and comparative examples 1 to 3
The invention adopts a heat treatment process to regulate and control the microstructure of the alloy, namely partial recrystallization annealing treatment, so that the alloy has a two-state microstructure (namely recrystallized austenite grains and unrecrystallized austenite grains) as shown in an Electron Back Scattering Diffraction (EBSD) diagram in figure 2. The results in table 1 show that the mechanical properties of the lightweight steel plate are excellent due to the adoption of the partial recrystallization annealing process, and are greatly improved compared with those of the conventional low-density steel subjected to complete annealing or solution treatment.
The austenite lightweight steel after rolling deformation has a stretched flat shape of crystal grains, and this microstructure undergoes recovery recrystallization during annealing or solution treatment to form coarse austenite equiaxed crystal grains, so that the alloy maintains excellent plasticity, but has low tensile strength. In this case, the alloy is strengthened by solid solution strengthening and grain boundary strengthening, and these strengthening methods have a limit to improvement of tensile strength. Based on the method, the invention provides a new process for regulating and controlling the microstructure of the light steel alloy, thereby improving the mechanical property. The alloy after rolling deformation is annealed for a short time, so that the alloy can not be completely recrystallized, and a two-state structure is obtained, as shown in figure 2, namely recrystallized austenite small grains of 2-4 mu m and flat unrecrystallized austenite grains of 30-40 mu m containing high-density dislocation. Unlike the microstructure of coarse austenite equiaxed grains, the strength of the lightweight steel of the present invention is greatly improved because dislocation strengthening is brought to the alloy due to the flat austenite grains containing a large amount of dislocations, while solid solution strengthening and grain boundary strengthening are performed. Under the combined action of solid solution strengthening, grain boundary strengthening and dislocation strengthening, the tensile strength of the partially recrystallized annealed light steel in the invention keeps a higher level, which is greatly superior to that of the conventional heat-treated light steel. At the same time, the duplex microstructure ensures excellent plasticity because the small recrystallized austenite grains have a very low dislocation density during the alloy drawing deformation process, and can accommodate a large number of dislocation products, such as slip bands, Taylor lattices and other dislocation structures, thereby ensuring plasticity. In addition, due to the strain distribution between the recrystallized grains and the unrecrystallized grains, the premature failure of the material caused by local strain concentration is avoided, which is also the reason for maintaining excellent shaping.
In light steel, after aging treatment, L is 1 2' type nanometer-sized kappa-carbide is precipitated and keeps coherent relation with austenite, the tensile strength of the alloy is improved, and meanwhile, the influence of plasticity loss is small, but the long-time aging causes the size of the kappa-carbide to be large, even the kappa-carbide is precipitated on grain boundaries, and the influence on the plasticity is disastrous. In order to further improve the mechanical property of the light steel, the material is subjected to aging treatment for different time periods on the basis of partial recrystallization annealing, so that the tensile strength of the light steel is further improved, as shown in table 1, the tensile strength of the aging-treated light steel is far higher than that of the aging-treated light steel in comparative examples 2 and 3, the aging time is greatly shortened, and the process is simpler. The reason is that the cold-rolled steel sheet of the present invention, after being subjected to partial recrystallization annealing, contains a large number of defects such as vacancies, dislocations, slip bands, etc. in the microstructure as shown in fig. 3 and 4, and since the atomic diffusion rate is increased at the defects, Al and C elements are segregated at the defects to promote the generation of κ -carbides as shown in fig. 5, the aging time is greatly shortened (10 to 60min vs20 to 40h), and the strength is greatly improved.
Compared with the traditional complete annealing (solution treatment) and aging treatment, the preparation method provided by the invention has the advantages that the cold-rolled sheet contains a partially recrystallized microstructure, the heat treatment process is simpler, the tensile strength is more excellent, and a new thought is provided for improving the strengthening mode of the light steel cold-rolled sheet.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (7)
1. An Fe-Mn-Al-C series austenitic light steel comprises the following elements in percentage by mass: 1.2-1.4% of C, 9-11% of Al, 25-30% of Mn and the balance of Fe;
the microstructure of the Fe-Mn-Al-C system austenitic light steel comprises small recrystallized austenite grains and flat unrecrystallized austenite grains; the size of the recrystallized austenite small crystal grains is 2-4 mu m; the size of the flat unrecrystallized austenite grains is 30-40 mu m;
the density of the Fe-Mn-Al-C system austenitic light steel is 6.62g/cm 3 ；
The preparation method of the Fe-Mn-Al-C series austenite lightweight steel comprises the following steps:
smelting a metal raw material to obtain an alloy ingot; the composition of the metal raw material is consistent with the element composition of the Fe-Mn-Al-C series austenitic light steel;
carrying out hot forging treatment on the alloy cast ingot to obtain an alloy forging material;
homogenizing the alloy forging material to obtain a uniform alloy forging material;
carrying out hot rolling treatment on the uniform chemical combination gold forging material to obtain a hot-rolled alloy plate blank;
performing cold rolling treatment on the hot-rolled alloy plate blank to obtain a cold-rolled alloy plate blank;
annealing the cold-rolled alloy plate blank to obtain Fe-Mn-Al-C series austenitic light steel; the temperature of the annealing treatment is 800-900 ℃, and the heat preservation time of the annealing treatment is 3-15 min;
the cold rolling treatment is carried out at room temperature; the cold rolling treatment is multi-pass rolling deformation, and the reduction of each pass is not more than 5%; the total deformation amount of the cold rolling treatment is 30-40%;
after the annealing treatment, the method further comprises the following steps: carrying out aging treatment on the obtained annealed cold-rolled alloy plate blank to obtain Fe-Mn-Al-C series austenite lightweight steel; the temperature of the aging treatment is 500-600 ℃; the heat preservation time of the aging treatment is 10-60 min.
2. The Fe-Mn-Al-C austenitic light steel according to claim 1, characterized in that the volume content of the recrystallized austenitic small grains is 8-10%; the volume content of the flat unrecrystallized austenite grains is 90-92%.
3. A method of producing an Fe-Mn-Al-C austenitic light steel as set forth in any of claims 1-2, comprising the steps of:
smelting a metal raw material to obtain an alloy ingot; the composition of the metal material is in accordance with the elemental composition of the Fe-Mn-Al-C austenitic light steel set forth in any one of claims 1 to 2;
carrying out hot forging treatment on the alloy cast ingot to obtain an alloy forging material;
homogenizing the alloy forging stock to obtain a uniform alloy forging stock;
carrying out hot rolling treatment on the uniform chemical combination gold forging material to obtain a hot-rolled alloy plate blank;
performing cold rolling treatment on the hot-rolled alloy plate blank to obtain a cold-rolled alloy plate blank;
annealing the cold-rolled alloy plate blank to obtain Fe-Mn-Al-C series austenitic light steel; the temperature of the annealing treatment is 800-900 ℃, and the heat preservation time of the annealing treatment is 3-15 min.
4. The method according to claim 3, wherein the temperature of the hot forging treatment is 1125 to 1180 ℃; the hot forging treatment is multi-pass forging.
5. The preparation method according to claim 3, wherein the temperature of the homogenization treatment is 1150-1200 ℃, the heat preservation time of the homogenization treatment is 120-180 min, and the homogenization treatment is followed by water cooling to room temperature.
6. The production method according to claim 3, wherein the temperature of the hot rolling treatment is 950 to 1100 ℃; the hot rolling treatment is multi-pass hot rolling deformation, and the reduction of each pass is not more than 20%; the total deformation amount of the hot rolling treatment is 80-85%.
7. The method according to claim 6, wherein the hot rolling is performed by water quenching to room temperature.
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| CN112877606A (en) * | 2021-01-12 | 2021-06-01 | 钢铁研究总院 | Ultrahigh-strength full-austenite low-density steel and preparation method thereof |
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| CN111850419A (en) * | 2020-07-31 | 2020-10-30 | 燕山大学 | High-manganese austenitic steel and preparation method thereof |
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