CN116987959A - Corrosion-resistant high-strength-toughness medium-manganese steel medium plate and preparation method thereof - Google Patents

Corrosion-resistant high-strength-toughness medium-manganese steel medium plate and preparation method thereof Download PDF

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CN116987959A
CN116987959A CN202210439991.8A CN202210439991A CN116987959A CN 116987959 A CN116987959 A CN 116987959A CN 202210439991 A CN202210439991 A CN 202210439991A CN 116987959 A CN116987959 A CN 116987959A
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medium
corrosion
strength
manganese steel
toughness
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刘韬
杜林秀
高秀华
吴红艳
蓝慧芳
董营
孙超
段东明
李东晖
陶振
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Nanjing Iron and Steel Co Ltd
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Nanjing Iron and Steel Co Ltd
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    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • 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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    • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • 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
    • 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
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • 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
    • 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
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • 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
    • 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
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
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    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
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    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

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Abstract

The invention discloses a corrosion-resistant high-strength and high-toughness medium-manganese steel medium plate and a preparation method thereof, wherein Cr, ni, mo, ti, cu element mixing proportion is adopted to compensate potential drop caused by adding a large amount of Mn element; and fine grains of the rust layer to prevent dissolved oxygen from penetrating into a matrix in the rust layer, thereby reducing the corrosion rate of the medium manganese steel; meanwhile, in order to prevent the addition of excessive alloy elements from generating larger carbide precipitated phases in a tissue and strongly deteriorating the impact performance of the material, a low-temperature rolling method is adopted to introduce more dislocation and distortion energy, so that the content of the carbide precipitated phases is reduced and the impact performance is improved; the invention has the beneficial effects that: the corrosion performance of the medium manganese steel is improved, meanwhile, the impact energy at minus 40 ℃ is more than or equal to 110J, and the low-temperature impact energy is not obviously reduced; in addition, the method has simple operation process and is easy to realize industrial production.

Description

Corrosion-resistant high-strength-toughness medium-manganese steel medium plate and preparation method thereof
Technical Field
The invention belongs to the technical field of metallurgy, relates to medium manganese steel, and in particular relates to corrosion-resistant high-strength and high-toughness medium manganese steel and a preparation method thereof.
Background
With the rapid development of science and technology, people are developing new times of ocean and utilizing ocean. The exploration, protection and development of the ocean are very important for all countries. The utilization of ocean resources is very important for the development of China because China has long coastline and wide territory. Exploration and development of ocean resources and protection of ocean interests are all dependent on advanced ocean engineering equipment. With the gradual trend of heavy load, large-scale and automatic development of ocean engineering equipment, the safety requirement of equipment is increased, and the ocean engineering steel is also provided with higher performance requirements. Therefore, the steel has high strength and toughness, is easy to weld and is corrosion-resistant, and is a development trend of the steel for ocean engineering. The research and development of the high-quality ocean engineering steel with independent intellectual property is significant for guaranteeing national energy safety, realizing the development and utilization of ocean resources and improving comprehensive national force.
At present, 355-460MPa steel plates are most widely applied in marine engineering equipment manufacturing. The 690 MPa-level ocean engineering steel for key parts of a large ocean structure has the characteristics of high strength, low cost and simple process. Compared with the traditional medium plate, the medium manganese steel medium plate has a plurality of unique advantages. Firstly, the component design of the medium manganese steel obviously improves the hardenability of the material, and is favorable for preparing a medium steel plate with excellent and uniform structure performance; secondly, mn element can be dissolved in a matrix material in a large amount, so that the strength of the steel is obviously improved. Therefore, the addition of Mn element can reduce the content of C element in steel in proper amount, and improve the welding performance; finally, mn element is used as powerful austenite stabilizing element, which can enlarge austenite phase region obviously, and after tempering at lower temperature, the medium manganese steel obtains high strength martensite matrix and a certain amount of residual austenite structure, and has mechanical properties of high strength and high-low temperature toughness.
However, a large amount of Mn element added to steel can lead to the decrease of the self-corrosion potential of the steel, and the corrosion resistance of medium manganese steel is relatively poor. And the final structure of the medium manganese steel is a composite structure of tempered martensite and residual austenite, micro cells are easy to form in the corrosion process, and the corrosion rate is accelerated. Meanwhile, the tempered martensite matrix contains a large number of large-angle grain boundaries, and the grain boundaries in the structure can be higher and the corrosion resistance is poorer. The steel for ocean engineering is in seawater environment for a long time and is corroded by multi-field coupling conditions such as temperature, humidity, chloride ion concentration and the like, so that the corrosion degradation phenomenon is very easy to occur, and the service life of ocean engineering equipment is shortened. The common corrosion prevention methods for the steel for the ocean engineering at present include coating protection, paint protection and the like. But these methods not only increase the cost but also make maintenance difficult. Therefore, how to develop and improve the corrosion resistance of the manganese steel through composition design and process is a problem to be solved urgently.
Disclosure of Invention
Aiming at the problem of poor corrosion resistance of the medium manganese steel, the invention provides a corrosion-resistant high-strength and high-toughness medium manganese steel medium plate, wherein Cr, ni, mo, ti, cu element mixing proportion is adopted to improve the self-corrosion potential of the medium manganese steel, so that potential drop caused by adding a large amount of Mn element is compensated; the Cr, ni, mo, ti, cu element is enriched in the rust layer in the corrosion process, so that grains of the rust layer are thinned, and the penetration of dissolved oxygen to a matrix in the rust layer is blocked, so that the corrosion rate of medium manganese steel is reduced; meanwhile, in order to prevent the addition of excessive alloy elements from generating larger carbide precipitated phases in a tissue and strongly deteriorating the impact performance of the material, a low-temperature rolling method is adopted to introduce more dislocation and distortion energy, so that the diffusion efficiency of Mn element to austenite in the tempering process is accelerated, the content of residual austenite is increased, more C element is enriched in the residual austenite, the content of carbide precipitated phases is reduced, and the impact performance is improved;
the medium manganese steel comprises the following chemical components in percentage by weight: c: 0.02-0.08%, mn: 4.00-8.00%, si:0.10 to 0.5 percent, S: < 0.01%, P: < 0.01%, al:0.01 to 0.05 percent, cu:0.02 to 0.5 percent, ni:0.02 to 0.60 percent, mo: 0.02-0.40%, cr: 0.02-3.0%, ti: 0.02-0.4%, and the balance of Fe and other unavoidable impurities; the medium manganese steel structure is a composite structure of tempered martensite and retained austenite.
The thickness of the corrosion-resistant high-strength and high-toughness medium manganese steel medium plate is 20-50 mm, the yield strength is 690-750 MPa, the tensile strength is 780-850 MPa, the elongation is 26-35%, and the impact energy at minus 40 ℃ is more than or equal to 110J.
The preparation process of the corrosion-resistant high-strength and high-toughness medium manganese steel plate comprises the following steps:
(1) Hot rolling treatment
Heating the alloy blank to 1000-1200 ℃ along with a furnace according to the weight ratio, and preserving heat for 2h; preparing a blank with the thickness of 100mm, performing two-stage controlled rolling, performing 4-pass rough rolling on the austenitized blank, and performing 5-pass finish rolling; the rough rolling temperature is 1000-1050 ℃, and the finish rolling temperature is controlled at 780-880 ℃; after finishing finish rolling, cooling to room temperature at a cooling rate of 15-35 ℃/s to obtain a quenched medium plate;
(2) Tempering treatment
Heating the furnace to 630-690 ℃, placing the quenched medium plate into the furnace, preserving heat for 50-100 min after reaching the temperature, and then air-cooling to room temperature to obtain the corrosion-resistant high-strength and high-toughness medium plate.
The invention has the beneficial effects that: the corrosion performance of the medium manganese steel is improved, meanwhile, the impact energy at minus 40 ℃ is more than or equal to 110J, and the low-temperature impact energy is not obviously reduced; in addition, the method has simple operation process and is easy to realize industrial production.
Drawings
FIG. 1 is a schematic process diagram of the preparation method of the present invention;
FIG. 2 is a metallographic structure of the corrosion-resistant high-strength and high-toughness medium-manganese medium plate of example 1;
FIG. 3 is an SEM morphology of the corrosion-resistant high strength and toughness medium and heavy plate of example 1.
FIG. 4 is a graph showing the relationship between corrosion loss and corrosion weight of a high strength and toughness medium manganese plate and Q345B in examples 1-3
FIG. 5 is an electrochemical polarization curve of the corrosion-resistant high-strength and high-toughness medium-manganese corrosion sample of example 1 at different cycles.
FIG. 6 is an SEM morphology of the corrosion-resistant high strength and toughness medium and heavy plate rust layer of example 1.
Detailed Description
The hot rolling mill adopted in the embodiment of the invention is a phi 450 hot rolling mill designed and manufactured by a northeast university rolling technology and a continuous rolling automation national key laboratory;
the heating furnace adopted in the hot rolling treatment is a high-temperature box-type resistance furnace, and the model is RX4-85-13B;
the heating furnace adopted in tempering treatment is a box-type resistance furnace, and the model is RX-36-10;
the corrosion test equipment adopts a periodic infiltration corrosion test box, and the model is ZQFS-1200OZ.
Example 1
The preparation method of the corrosion-resistant high-strength and toughness ultra-low carbon medium-manganese medium-thickness plate with the thickness of 20mm comprises the following process steps:
(1) Hot rolling treatment
Heating the alloy blank to 1200 ℃ along with a furnace, and preserving heat for 3 hours, wherein the alloy blank comprises the following chemical components in percentage by weight: c:0.06%, mn:4.0%, si:0.27%, S:0.002%, P:0.003%, al:0.02%, cu:0.34%, ni:0.60%, mo:0.2%, cr:1.22%, ti:0.4%, the balance being Fe and other unavoidable impurities. Preparing a blank with the thickness of 130mm, then performing two-stage controlled rolling, and performing 4-pass rough rolling on the austenitized blank, wherein the reduction rate is 50.0%; after the temperature is reached, 5-pass finish rolling is carried out, the rolling reduction is 50.0%, the hot rolled plate with the thickness of 20mm is obtained by rolling, the rough rolling temperature is 1000-1026 ℃, and the finish rolling temperature is 780-807 ℃. And (3) after the hot rolling is finished, cooling the medium plate to room temperature at a cooling rate of 35 ℃/s to obtain the quenched medium plate.
(2) Tempering treatment
Heating the furnace to 630 ℃, placing the quenched medium plate into the furnace, preserving heat for 50min after the temperature is reached, and then air-cooling to room temperature to obtain the corrosion-resistant high-toughness ultra-low carbon medium-manganese medium plate with the thickness of 20 mm. And the final medium plate structure is a composite structure of tempered martensite and residual austenite. The metallographic structure of the corrosion-resistant high-toughness medium-manganese thick plate in example 1 is shown in fig. 2, and the SEM morphology structure of the corrosion-resistant high-toughness medium-manganese thick plate in example 1 is shown in fig. 3.
(3) Corrosion test
The corrosion resistance test of the corrosion-resistant high-strength and high-toughness medium-manganese medium plate prepared by the embodiment: the accelerated corrosion test is carried out by using a periodic infiltration corrosion test box by taking Q345B as a reference sample, and the accelerated corrosion test is carried out by using a 3.5% NaCl solution (simulating marine environment). The temperature of the aqueous solution is controlled at 45 ℃, the baking temperature in the test box is controlled at 70 ℃, and the humidity in the box is 70%. Each soak period was 1h, with a soak time of 0.2h, and the test was run for 360h. And sampling at the beginning of the experiment for 24 hours, 72 hours, 144 hours, 240 hours and 360 hours respectively for observing the morphology, measuring the weightlessness and observing the morphology of the corrosion product. And drawing a relation curve of corrosion weightlessness corrosion time, as shown in fig. 4. Electrochemical testing was performed on the rusted sample and a polarization curve was plotted, see fig. 5. The SEM morphology of the rust layer of the corrosion sample is shown in FIG. 6.
The corrosion-resistant high-strength and high-toughness ultra-low carbon medium-manganese medium-thickness plate structure with the thickness of 20mm is a tempered martensite and residual austenite composite structure, the yield strength is 750MPa, the tensile strength is 850MPa, the elongation after fracture is 35%, and the impact energy at minus 40 ℃ is 164J.
Example 2
The preparation method of the corrosion-resistant high-strength and toughness ultra-low carbon medium-manganese medium-thickness plate with the thickness of 30mm comprises the following process steps:
(1) Hot rolling treatment
Heating the alloy blank to 1000 ℃ along with a furnace, and preserving heat for 3 hours, wherein the alloy blank comprises the following chemical components in percentage by weight: c:0.08%, mn:5.00%, si:0.10%, S:0.002%, P:0.003%, al:0.05%, cu:0.02%, ni:0.4%, mo:0.4%, cr:3.0%, ti:0.02%, the balance being Fe and other unavoidable impurities. Preparing a blank with the thickness of 130mm, then performing two-stage controlled rolling, and performing 4-pass rough rolling on the austenitized blank, wherein the reduction rate is 55.0%; after the temperature is reached, 5-pass finish rolling is carried out, the rolling reduction is 45.0%, the hot rolled plate with the thickness of 30mm is obtained by rolling, the rough rolling temperature is 1020-1041 ℃, and the finish rolling temperature is 790-830 ℃. And (3) after the hot rolling is finished, cooling the medium plate to room temperature at a cooling rate of 22 ℃/s, and obtaining the quenched medium plate.
(2) Tempering treatment
And (3) after the temperature of the heating furnace is raised to 670 ℃, placing the steel plate subjected to hot rolling quenching into the furnace, preserving heat for 70min after the temperature is raised, and then air-cooling to room temperature to obtain the corrosion-resistant high-toughness ultra-low carbon medium-manganese medium-thickness plate with the thickness of 30 mm.
The corrosion resistance test of the corrosion-resistant high-strength and high-toughness medium-manganese medium plate prepared by the embodiment: the accelerated corrosion test is carried out by using a periodic infiltration corrosion test box by taking Q345B as a reference sample, and the accelerated corrosion test is carried out by using a 3.5% NaCl solution (simulating marine environment). The temperature of the aqueous solution is controlled at 45 ℃, the baking temperature in the test box is controlled at 70 ℃, and the humidity in the box is 70%. Each soak period was 1h, with a soak time of 0.2h, and the test was run for 360h. Samples were taken at 24h, 72h, 144h, 240h, 360h, respectively, at the beginning of the experiment for weight loss measurements.
The corrosion-resistant high-strength and high-toughness ultra-low carbon medium-manganese medium-thickness plate structure with the thickness of 30mm is a tempered martensite and residual austenite composite structure, the yield strength is 720MPa, the tensile strength is 830MPa, the elongation after fracture is 31%, and the impact energy at the temperature of minus 40 ℃ is 134J.
Example 3
The preparation method of the corrosion-resistant high-strength and toughness ultra-low carbon medium-manganese medium-thickness plate with the thickness of 50mm comprises the following process steps:
(1) Hot rolling treatment
Heating the alloy blank to 1100 ℃ along with a furnace, and preserving heat for 5 hours, wherein the alloy blank comprises the following chemical components in percentage by weight: c:0.02%, mn:8.00%, si:0.50%, S:0.002%, P:0.003%, al:0.01%, cu:0.5%, ni:0.02%, mo:0.02%, cr:0.02%, ti:0.2%, the balance being Fe and other unavoidable impurities. Preparing a blank with the thickness of 150mm, then performing two-stage controlled rolling, and performing 4-pass rough rolling on the austenitized blank, wherein the reduction rate is 62.5%; after the temperature is reached, 5-pass finish rolling is carried out, the rolling reduction is 37.5%, the hot rolled plate with the thickness of 50mm is obtained by rolling, the rough rolling temperature is 1030-1050 ℃, and the finish rolling temperature is 830-880 ℃. And (3) after the hot rolling is finished, cooling the medium plate to room temperature at a cooling rate of 15 ℃/s to obtain the quenched medium plate.
(2) Tempering treatment
After the temperature of the heating furnace is raised to 690 ℃, the steel plate after hot rolling quenching is put into the furnace, heat preservation is carried out for 100min after the temperature is reached, and then air cooling is carried out to room temperature. And obtaining the corrosion-resistant high-strength and high-toughness medium-manganese thick plate with the thickness of 50 mm.
The corrosion resistance test of the corrosion-resistant high-strength and high-toughness medium-manganese medium plate prepared by the embodiment: the accelerated corrosion test is carried out by using a periodic infiltration corrosion test box by taking Q345B as a reference sample, and the accelerated corrosion test is carried out by using a 3.5% NaCl solution (simulating marine environment). The temperature of the aqueous solution is controlled at 45 ℃, the baking temperature in the test box is controlled at 70 ℃, and the humidity in the box is 70%. Each soak period was 1h, with a soak time of 0.2h, and the test was run for 360h. Samples were taken at 24h, 72h, 144h, 240h, 360h, respectively, at the beginning of the experiment for weight loss measurements.
The corrosion-resistant high-strength and high-toughness ultra-low carbon medium-manganese medium-thickness plate structure with the thickness of 50mm is tempered martensite and residual austenite, the yield strength is 690MPa, the tensile strength is 780MPa, the elongation after fracture is 26%, and the impact energy at minus 40 ℃ is 110J.
Comparative example 1
The preparation method of the ultra-low carbon medium-manganese thick plate with the thickness of 20mm comprises the following process steps:
(1) Hot rolling treatment
Heating the alloy blank to 1200 ℃ along with a furnace, and preserving heat for 3 hours, wherein the alloy blank comprises the following chemical components in percentage by weight: c:0.06%, mn:4.0%, si:0.27%, S:0.002%, P:0.003%, al:0.02%, cu:0.34%, ni:0.60%, mo:0.2%, cr:1.22%, ti:0.4%, the balance being Fe and other unavoidable impurities. Preparing a blank with the thickness of 130mm, then performing two-stage controlled rolling, and performing 3-pass rough rolling on the austenitized blank, wherein the reduction rate is 50.0%; after the temperature is reached, 3-pass finish rolling is carried out, the rolling reduction is 50.0%, the hot rolled plate with the thickness of 20mm is obtained by rolling, the rough rolling temperature is 1000-1026 ℃, and the finish rolling temperature is 910-980 ℃. And (3) after the hot rolling is finished, cooling the medium plate to room temperature at a cooling rate of 35 ℃/s to obtain the quenched medium plate.
(2) Tempering treatment
Heating the furnace to 630 ℃, placing the quenched medium plate into the furnace, preserving heat for 50min after the temperature is reached, and then air-cooling to room temperature to obtain the ultra-low carbon medium-manganese medium plate with the thickness of 20 mm. And the final medium plate structure is a composite structure of tempered martensite and residual austenite.
The corrosion-resistant high-strength and high-toughness ultra-low carbon medium-manganese medium-thickness plate structure with the thickness of 20mm is a tempered martensite and residual austenite composite structure, the yield strength is 710MPa, the tensile strength is 810MPa, the elongation after fracture is 19%, and the impact energy at the temperature of minus 40 ℃ is 45J.
Comparative example 2
The preparation method of the ultra-low carbon medium-manganese thick plate with the thickness of 20mm comprises the following process steps:
(1) Hot rolling treatment
Heating the alloy blank to 1200 ℃ along with a furnace, and preserving heat for 3 hours, wherein the alloy blank comprises the following chemical components in percentage by weight: c:0.06%, mn:4.0%, si:0.27%, S:0.002%, P:0.003%, al:0.02%, cu:0.34%, ni:0.60%, mo:0.2%, cr:1.22%, ti:0.4%, the balance being Fe and other unavoidable impurities. Preparing a blank with the thickness of 130mm, then performing two-stage controlled rolling, and performing 4-pass rough rolling on the austenitized blank, wherein the reduction rate is 50.0%; after the temperature is reached, 5-pass finish rolling is carried out, the rolling reduction is 50.0%, the hot rolled plate with the thickness of 20mm is obtained by rolling, the rough rolling temperature is 1000-1026 ℃, and the finish rolling temperature is 910-980 ℃. And (3) after the hot rolling is finished, cooling the medium plate to room temperature at a cooling rate of 35 ℃/s to obtain the quenched medium plate.
(2) Tempering treatment
Heating the furnace to 630 ℃, placing the quenched medium plate into the furnace, preserving heat for 50min after the temperature is reached, and then air-cooling to room temperature to obtain the ultralow-carbon medium-manganese medium plate with the thickness of 20 mm. And the final medium plate structure is a composite structure of tempered martensite and residual austenite.
The corrosion-resistant high-strength and high-toughness ultra-low carbon medium-manganese medium-thickness plate structure with the thickness of 20mm is a tempered martensite and residual austenite composite structure, the yield strength is 730MPa, the tensile strength is 840MPa, the elongation after fracture is 20%, and the impact energy at the temperature of minus 40 ℃ is 60J.
The finish rolling temperatures of comparative example 1 and comparative example 2 are 910 ℃ to 980 ℃ respectively, the finish rolling temperatures are 780 ℃ to 880 ℃ higher than the finish rolling temperatures of the invention, the rough rolling and finish rolling passes of the blanks of comparative example 1 are less than those of examples 1 to 3, the elongation after fracture of comparative example 1 is 19%, the impact energy of-40 ℃ is 45J, the elongation after fracture of comparative example 2 is 20%, the impact energy of-40 ℃ is 60J, the elongation of examples 1 to 3 of the invention is 26 to 35%, and the impact energy of-40 ℃ is not less than 110J. Therefore, more dislocation and distortion energy are introduced by adopting a low-temperature rolling method, the diffusion efficiency of Mn element to austenite in the tempering process is accelerated, the content of residual austenite is increased, more C element is enriched in the residual austenite, the content of carbide precipitated phase is reduced, and the impact performance of medium manganese steel can be obviously improved.

Claims (3)

1. A corrosion-resistant high-strength and high-toughness medium manganese steel medium plate is characterized in that: adopting Cr, ni, mo, ti, cu element mixing proportion to improve the self-corrosion potential of the medium manganese steel, thereby compensating the potential drop caused by adding a large amount of Mn element; the Cr, ni, mo, ti, cu element is enriched in the rust layer in the corrosion process, so that grains of the rust layer are thinned, and the penetration of dissolved oxygen to a matrix in the rust layer is blocked, so that the corrosion rate of medium manganese steel is reduced; meanwhile, in order to prevent the addition of excessive alloy elements from generating larger carbide precipitated phases in a tissue and strongly deteriorating the impact performance of the material, a low-temperature rolling method is adopted to introduce more dislocation and distortion energy, so that the diffusion efficiency of Mn element to austenite in the tempering process is accelerated, the content of residual austenite is increased, more C element is enriched in the residual austenite, the content of carbide precipitated phases is reduced, and the impact performance is improved;
the medium manganese steel comprises the following chemical components in percentage by weight: c: 0.02-0.08%, mn: 4.00-8.00%, si:0.10 to 0.5 percent, S: < 0.01%, P: < 0.01%, al:0.01 to 0.05 percent, cu:0.02 to 0.5 percent, ni:0.02 to 0.60 percent, mo: 0.02-0.40%, cr: 0.02-3.0%, ti: 0.02-0.4%, and the balance of Fe and other unavoidable impurities; the medium manganese steel structure is a composite structure of tempered martensite and retained austenite.
2. The corrosion-resistant high-strength and high-toughness medium manganese steel plate according to claim 1, wherein: the thickness of the corrosion-resistant high-strength and high-toughness medium manganese steel medium plate is 20-50 mm, the yield strength is 690-750 MPa, the tensile strength is 780-850 MPa, the elongation is 26-35%, and the impact energy at minus 40 ℃ is more than or equal to 110J.
3. The corrosion-resistant high-strength and high-toughness medium manganese steel plate according to claim 1, wherein: the preparation process comprises the following steps:
(1) Hot rolling treatment
Heating the alloy blank to 1000-1200 ℃ along with a furnace according to the weight ratio, and preserving heat for 2-5h; preparing a blank with the thickness of 100-150mm, performing two-stage controlled rolling, performing 4-pass rough rolling on the austenitized blank, and performing 5-pass finish rolling; the rough rolling temperature is 1000-1050 ℃, and the finish rolling temperature is controlled at 780-880 ℃; after finishing finish rolling, cooling to room temperature at a cooling rate of 15-35 ℃/s to obtain a quenched medium plate;
(2) Tempering treatment
Heating the furnace to 630-690 ℃, placing the quenched medium plate into the furnace, preserving heat for 50-100 min after reaching the temperature, and then air-cooling to room temperature to obtain the corrosion-resistant high-strength and high-toughness medium plate.
CN202210439991.8A 2022-04-25 2022-04-25 Corrosion-resistant high-strength-toughness medium-manganese steel medium plate and preparation method thereof Pending CN116987959A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104805378A (en) * 2015-05-13 2015-07-29 东北大学 High strength and toughness ultra-low carbon medium manganese steel middle-thickness plate and preparation method thereof
CN104911475A (en) * 2015-06-25 2015-09-16 东北大学 Low-carbon medium-manganese high-toughness super-thick steel plate and preparation method thereof
CN108385037A (en) * 2018-03-23 2018-08-10 东北大学 A kind of ocean platform Ti microalloying medium managese steel cut deals and preparation method thereof
CN108660395A (en) * 2018-05-30 2018-10-16 东北大学 Manganese high-strength cut deal and quenching-dynamic partition production technology preparation method in a kind of 690MPa grades of low-carbon

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104805378A (en) * 2015-05-13 2015-07-29 东北大学 High strength and toughness ultra-low carbon medium manganese steel middle-thickness plate and preparation method thereof
CN104911475A (en) * 2015-06-25 2015-09-16 东北大学 Low-carbon medium-manganese high-toughness super-thick steel plate and preparation method thereof
CN108385037A (en) * 2018-03-23 2018-08-10 东北大学 A kind of ocean platform Ti microalloying medium managese steel cut deals and preparation method thereof
CN108660395A (en) * 2018-05-30 2018-10-16 东北大学 Manganese high-strength cut deal and quenching-dynamic partition production technology preparation method in a kind of 690MPa grades of low-carbon

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