High-manganese high-aluminum heat-resistant non-magnetic steel as well as preparation method and application thereof

Abstract

The invention discloses high-manganese high-aluminum heat-resistant non-magnetic steel and a preparation method and application thereof. The high-manganese high-aluminum heat-resistant non-magnetic steel comprises the following components in percentage by mass: 0.50%-1.50% of Si, 2.00%-4.00% of Al, 0.20%-2.00% of Mo, 0.25%-0.90% of W, 0.10%-0.30% of C, 21.0%-27.0% of Mn, less than or equal to 0.025% of P, less than or equal to 0.020% of S, 0.06%-0.20% of V, 0.02%-0.15% of Ti and the balance of Fe and inevitable impurities. According to the high-manganese high-aluminum heat-resistant non-magnetic steel provided by the embodiment of the invention, the heat resistance of the high-manganese high-aluminum heat-resistant non-magnetic steel can be effectively improved.

Description

Technical Field

[0001] The present application belongs to the field of metal material processing, and in particular relates to a high-manganese and high-aluminum heat-resistant non-magnetic steel and a preparation method and application thereof. Background Art

[0002] Non-magnetic steel refers to steel that is non-magnetic, cannot be magnetized, or has low magnetism. It is often used in working environments that require low magnetism and certain mechanical properties. For example, steel with a magnetic permeability of μ≤1.319×10-6H / m can be called non-magnetic steel. Currently, the non-magnetic steel widely used in industry has poor heat resistance and cannot serve for a long time in high temperature environments. Summary of the invention

[0003] The embodiments of the present application provide a high manganese and high aluminum heat-resistant non-magnetic steel and a preparation method and application thereof, which can improve the heat resistance of the high manganese and high aluminum non-magnetic steel.

[0004] In a first aspect, an embodiment of the present application provides a high manganese and high aluminum heat-resistant non-magnetic steel, and the high manganese and high aluminum heat-resistant non-magnetic steel includes, by mass percentage:

[0005] Si: 0.50%~1.50%, Al: 2.00%~4.00%, Mo: 0.20%~2.00%, W: 0.25%~0.90%, C: 0.10%~0.30%, Mn: 21.0%~27.0%, P≤0.025%, S≤0.020%, V: 0.06%~0.20%, Ti: 0.02%~0.15%, the balance is Fe and unavoidable impurities.

[0006] According to the embodiment of the first aspect of the present application, the yield strength R of the high manganese and high aluminum heat-resistant non-magnetic steel at 20°C to 25°C p0.2 ≥400Mpa; tensile strength R m ≥700MPa; elongation after fracture A≥30%; impact energy KV2 at -20℃≥180J; grain size is 7 to 9; relative magnetic permeability ≤1.002.

[0007] According to the embodiment of the first aspect of the present application, the yield strength R of the high manganese and high aluminum heat-resistant non-magnetic steel at 400°C to 700°C is p0.2 ≥300MPa; tensile strength R m ≥600MPa, elongation after fracture A≥30%; relative magnetic permeability of high manganese and high aluminum heat-resistant non-magnetic steel after cooling from 400℃~700℃ to 20℃~25℃ is ≤1.005.

[0008] In a second aspect, the present application provides a method for preparing high manganese and high aluminum heat-resistant non-magnetic steel, comprising:

[0009] Refining the crude molten steel to obtain refined molten steel, wherein the refined molten steel contains, by mass percentage, 21.0% to 27.0% Mn, 0.70% to 1.20% Si, 2.50% to 3.50% Al, 0.50% to 1.20% Mo, and 0.30% to 0.80% W;

[0010] Continuously casting the refined molten steel to obtain a continuously cast slab;

[0011] heating the continuous casting slab to obtain a heated continuous casting slab;

[0012] The heated continuous casting slab is rolled to obtain high manganese and high aluminum heat-resistant non-magnetic steel.

[0013] According to the embodiment of the second aspect of the present application, during the continuous casting of refined molten steel to obtain continuously cast slabs, the temperature of the molten steel in the tundish is 1430°C to 1450°C; the water nozzle insertion depth is 115mm to 125mm; and the water nozzle inclination angle is downward 10° to 15°.

[0014] According to the embodiment of the second aspect of the present application, in the process of heating the continuous casting slab to obtain the heated continuous casting slab, the solution treatment temperature of the continuous casting slab is 1160℃~1170℃, the furnace outlet temperature is 1180℃~1200℃, and the heating time is 1.25min / mm~1.45min / mm.

[0015] According to the embodiment of the second aspect of the present application, in the process of rolling the heated continuous casting slab to obtain high manganese and high aluminum heat-resistant non-magnetic steel, the starting rolling temperature of the heated continuous casting slab is 1100℃~1150℃, the final rolling temperature is 800℃~950℃, and the rolling thickness is 4mm~25mm.

[0016] According to an embodiment of the second aspect of the present application, the step of rolling the heated continuous casting slab to obtain the high manganese and high aluminum heat-resistant non-magnetic steel includes coiling the high manganese and high aluminum heat-resistant non-magnetic steel to obtain the coiled high manganese and high aluminum heat-resistant non-magnetic steel;

[0017] The coiling temperature is 500°C to 650°C.

[0018] According to an embodiment of the second aspect of the present application, the step of refining the crude molten steel to obtain the refined molten steel includes: smelting the raw molten steel in a converter to obtain the crude molten steel; and / or,

[0019] The step of coiling the high manganese and high aluminum heat-resistant non-magnetic steel to obtain the coiled high manganese and high aluminum heat-resistant non-magnetic steel includes air cooling the coiled high manganese and high aluminum heat-resistant non-magnetic steel.

[0020] In a third aspect, an embodiment of the present application provides an application of the high manganese and high aluminum heat-resistant non-magnetic steel obtained by the above-mentioned preparation method of the high manganese and high aluminum heat-resistant non-magnetic steel, and the application is at least selected from the following:

[0021] (1) Application in the preparation of submerged arc furnace parts;

[0022] (2) Application in the preparation of nuclear power equipment parts;

[0023] (3) Application in the preparation of power station unit components.

[0024] The high manganese and high aluminum heat-resistant non-magnetic steel in the embodiment of the present application can form a protective and dense oxide layer on the surface of the steel by increasing the Si content, thereby improving the high-temperature oxidation resistance of the heat-resistant steel; by increasing the Al content, not only can the steel be prompted to form a dense oxide layer in a high-temperature environment, but also the high-temperature mechanical properties and high-temperature softening temperature of the steel are improved; by adding Mo and W elements, the thermal stability of the steel matrix structure is improved; by regulating the content of Si, Al, Mo, W and C, Mn, P, S, V and Ti, it can be ensured that the high manganese and high aluminum non-magnetic steel has excellent heat resistance and can serve for a long time in a high-temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 This is a schematic diagram of a slab of high manganese and high aluminum heat-resistant non-magnetic steel provided in one embodiment of the present application;

[0027] Figure 2 is a schematic diagram of crystallizer temperature distribution provided by another embodiment of the present application;

[0028] Figure 3 This is a schematic diagram of a finished steel plate provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the application purpose, technical solution and beneficial technical effect of this application clearer, the application is further described in detail below in conjunction with the embodiments. It should be understood that the implementation regulations described in this specification are only for explaining this application, not for limiting this application.

[0030] For simplicity, the present application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an unclearly recorded range; and any lower limit can be combined with other lower limits to form an unclearly recorded range, and any upper limit can be combined with any other upper limit to form an unclearly recorded range. In addition, although not clearly recorded, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined with any other point or single value as its own lower limit or upper limit or with other lower limits or upper limits to form an unclearly recorded range.

[0031] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "includes..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0032] Unless otherwise specified, the values ​​of the parameters mentioned in this application can be measured by various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this application). Unless otherwise specified, the test temperature of the parameters mentioned in this application is 25° C. and the test pressure is standard atmospheric pressure.

[0033] The above application content of the present application is not intended to describe each disclosed embodiment or each implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided through a series of embodiments, and these implementation regulations can be used in various combinations. In each example, enumeration is only used as a representative group and should not be interpreted as exhaustive.

[0034] The following is a detailed description of the chemical components in the examples of this application:

[0035] C: Carbon is one of the most effective elements for solid solution strengthening and is also the most effective element for ensuring austenite stabilization. However, an increase in carbon content will also increase the difficulty of continuous casting production, resulting in excessive precipitation of cast carbides, reducing the plasticity of the ingot, and causing cracks to form on the surface of the continuous casting ingot. On the other hand, an increase in carbon content will deteriorate the welding and bending properties of the material. Therefore, in order to ensure the strength and austenite structure of the steel plate while taking into account the production, processing and application of the material, the carbon content of the steel plate is controlled at 0.10% to 0.30%.

[0036] Si: When the silicon content in steel reaches about 1%, heat-resistant steel can form a protective dense oxide layer on the surface of the steel plate under long-term high-temperature service conditions, thereby improving the high-temperature oxidation resistance of heat-resistant steel. In addition, silicon is also an alloy element with strong solid solution strengthening, so the silicon content is controlled at 0.70% to 1.20%.

[0037] Mn: Manganese is an austenite-forming element. A higher manganese content ensures that the material structure is austenite, thereby ensuring that the material still has extremely low magnetic permeability under high magnetic field strength. At the same time, the large amount of manganese added causes the austenite structure to undergo twin transformation during the strain process, thereby playing a role in fine grain strengthening and improving the plasticity and toughness of the material. In addition, the addition of manganese can reduce the density of steel and achieve lightweight applications, so the manganese content is controlled at 21.0% to 27.0%.

[0038] Al: Adding a certain amount of aluminum to steel can stabilize the austenite phase and inhibit the martensite phase transformation. Especially in the cold working process or under low temperature service conditions, an aluminum content of about 3% can prevent the transformation of austenite to martensite. Adding aluminum to steel can promote the material to form a dense oxide layer in a high temperature environment and improve the high temperature mechanical properties of the material. When the aluminum content increases, the high temperature softening temperature of the material can be increased. Therefore, the aluminum content is controlled at 2.50% to 3.50%.

[0039] W: An important solid solution strengthening element. The addition of tungsten helps to improve the thermal stability and creep properties of heat-resistant steel, and is beneficial to improving the steel's resistance to stress corrosion. Tungsten has a low self-diffusion coefficient. Adding tungsten to steel can effectively hinder dislocation movement, thereby improving the structural stability of heat-resistant steel under high temperature and long-term service conditions. Therefore, the tungsten content is controlled at W: 0.30% to 0.80%.

[0040] Mo: One of the most important heat-resistant elements. Adding molybdenum to steel can increase the tempering brittleness temperature. The appearance of molybdenum-containing precipitation phase at high temperature hinders the movement and expansion of dislocations, thereby improving the high-temperature strength of the material, enhancing tempering stability and high-temperature fatigue performance. Therefore, the molybdenum content is controlled at 0.50% to 1.50%.

[0041] V and Ti: Both are strong carbide-forming elements with strong precipitation strengthening effects. During solidification and rolling, the titanium-containing precipitate phase can play a strong fine grain strengthening effect. During high temperature service, the precipitate phase formed by the two further plays a precipitation strengthening effect. Therefore, the vanadium content is controlled at 0.06% to 0.20%, and the titanium content is controlled at 0.02% to 0.15%.

[0042] Ordinary low-magnetic steel or non-magnetic steel has low Si and Al contents, and no heat-resistant elements (such as Mo and W) are added, resulting in poor thermal properties of low-magnetic steel or non-magnetic steel, which cannot be used for a long time in a high-temperature environment. The high-manganese and high-aluminum heat-resistant non-magnetic steel of the embodiment of the present application can form a protective dense oxide layer on the surface of the steel by increasing the Si content, thereby improving the high-temperature oxidation resistance of the heat-resistant steel; by increasing the Al content, it can not only promote the formation of a dense oxide layer in a high-temperature environment, but also improve the high-temperature mechanical properties and high-temperature softening temperature of the steel; by adding Mo and W elements, the thermal stability of the steel matrix organization is improved; by regulating the content between Si, Al, Mo, W and C, Mn, P, S, V and Ti, it can be ensured that the high-manganese and high-aluminum non-magnetic steel has excellent heat resistance and can be used for a long time in a high-temperature environment.

[0043] In order to solve the problems of the prior art, the embodiments of the present application provide a high-manganese and high-aluminum heat-resistant non-magnetic steel and a preparation method and application thereof.

[0044] The embodiment of the present application provides a high manganese and high aluminum heat-resistant non-magnetic steel, and the high manganese and high aluminum heat-resistant non-magnetic steel includes, by mass percentage:

[0045] Si: 0.50%~1.50%, Al: 2.00%~4.00%, Mo: 0.20%~2.00%, W: 0.25%~0.90%, C: 0.10%~0.30%, Mn: 21.0%~27.0%, P≤0.025%, S≤0.020%, V: 0.06%~0.20%, Ti: 0.02%~0.15%, the balance is Fe and unavoidable impurities.

[0046] Preferably, the high manganese and high aluminum heat-resistant non-magnetic steel comprises, by mass percentage:

[0047] Si: 0.60%~1.30%, Al: 2.20%~3.80%, Mo: 0.30%~1.80%, W: 0.28%~0.85%, C: 0.10%~0.30%, Mn: 21.0%~27.0%, P≤0.025%, S≤0.020%, V: 0.06%~0.20%, Ti: 0.02%~0.15%, the balance is Fe and unavoidable impurities.

[0048] More preferably, the high manganese and high aluminum heat-resistant non-magnetic steel comprises, by mass percentage:

[0049] Si: 0.70%~1.20%, Al: 2.50%~3.50%, Mo: 0.50%~1.50%, W: 0.30%~0.80%, C: 0.10%~0.30%, Mn: 21.0%~27.0%, P≤0.025%, S≤0.020%, V: 0.06%~0.20%, Ti: 0.02%~0.15%, the balance is Fe and unavoidable impurities.

[0050] Particularly preferably, the high manganese and high aluminum heat-resistant non-magnetic steel comprises, by mass percentage:

[0051] Si: 0.80%~1.20%, Al: 2.60%~3.40%, Mo: 0.55%~1.00%, W: 0.40%~0.65%, C: 0.15%~0.30%, Mn: 21.5%~25.0%, P≤0.020%, S≤0.018%, V: 0.08%~0.20%, Ti: 0.03%~0.15%, the balance is Fe and unavoidable impurities.

[0052] In the embodiment of the present application, by increasing the mass percentage of Si in the steel to 0.50% to 1.50%, a protective dense oxide layer can be formed on the surface of the steel plate under long-term high-temperature service conditions, thereby improving the high-temperature oxidation resistance of the heat-resistant steel; by increasing the mass percentage of Al in the steel to 2.00% to 4.00%, not only can the steel be prompted to form a dense oxide layer in a high-temperature environment, but also the high-temperature mechanical properties and high-temperature softening temperature of the steel are improved; by adding a Mo element with a mass percentage of 0.20% to 2.00% and a W element with a mass percentage of 0.25% to 0.90%, the thermal stability of the steel matrix structure is improved; by regulating the mass percentage of Si, Al, Mo, W and C, Mn, P, S, V and Ti, it can be ensured that the high-manganese and high-aluminum non-magnetic steel has excellent heat resistance and can serve for a long time in a high-temperature environment.

[0053] In some optional embodiments, the high manganese and high aluminum heat-resistant non-magnetic steel structure is a fully austenitic structure.

[0054] In some optional embodiments, the yield strength R of the high manganese and high aluminum heat-resistant non-magnetic steel at 20°C to 25°C is p0.2 ≥400Mpa; tensile strength R m ≥700MPa; elongation after fracture A≥30%; impact energy KV2 at -20℃≥180J; grain size is 7 to 9; relative magnetic permeability ≤1.002.

[0055] Preferably, the yield strength of high manganese and high aluminum heat-resistant non-magnetic steel at 25°C is 530Mpa≤R p0.2 ≤560Mpa; tensile strength 785MPa≤Rm ≤850MPa; elongation after fracture 45%≤A≤58%; impact energy at -20℃ 224J≤KV2≤256J; grain size is 8.5~9; relative magnetic permeability ≤1.001.

[0056] In some optional embodiments, the yield strength R of the high manganese and high aluminum heat-resistant non-magnetic steel at 400°C to 700°C is p0.2 ≥300MPa; tensile strength R m ≥600MPa, elongation after fracture A≥30%; the relative permeability of the high manganese and high aluminum heat-resistant non-magnetic steel after cooling from 400℃~700℃ to 20℃~25℃ is ≤1.005.

[0057] Preferably, the yield strength of the high manganese and high aluminum heat-resistant non-magnetic steel at 500°C to 650°C is 512MPa≤R p0.2 ≤530MPa; tensile strength 745MPa≤R m ≤810MPa, elongation after fracture 55%≤A≤68%; the relative magnetic permeability of the high manganese and high aluminum heat-resistant non-magnetic steel after cooling from 500℃~650℃ to 25℃ is ≤1.002.

[0058] The present application provides a method for preparing high manganese and high aluminum heat-resistant non-magnetic steel, comprising:

[0059] Refining the crude molten steel to obtain refined molten steel, wherein the refined molten steel contains, by mass percentage, 21.0% to 27.0% Mn, 0.70% to 1.20% Si, 2.50% to 3.50% Al, 0.50% to 1.50% Mo, and 0.30% to 0.80% W;

[0060] Continuously casting the refined molten steel to obtain a continuously cast slab;

[0061] heating the continuous casting slab to obtain a heated continuous casting slab;

[0062] The heated continuous casting slab is rolled to obtain high manganese and high aluminum heat-resistant non-magnetic steel.

[0063] In some optional embodiments, the step of refining the crude molten steel to obtain the refined molten steel includes smelting the raw molten steel in a converter to obtain the crude molten steel.

[0064] Adding electrolytic manganese during the process of tapping crude steel from the converter can make the Mn content of the molten steel after tapping the converter reach 14% to 18%, thereby preliminarily increasing the mass content of Mn in the molten steel.

[0065] In some optional embodiments, the refining is performed by refining the crude molten steel in a LF refining furnace.

[0066] By adding manganese alloy, ferrosilicon, aluminum block, molybdenum block, tungsten alloy, nitride and ferrotitanium in the process of refining crude molten steel, it can be ensured that the mass percentage of Mn in the refined molten steel is 21.0% to 27.0%, the mass percentage of Si is 0.70% to 1.20%, the mass percentage of Al is 2.50% to 3.50%, the mass percentage of Mo is 0.50% to 1.50%, and the mass percentage of W is 0.30% to 0.80%, thereby further increasing the mass percentages of Mn, Si, Al, Mo and W in the molten steel, reducing the solidification heat transfer efficiency of the steel, improving the thermal stability of the matrix structure, and achieving the effect of improving the heat resistance of the steel.

[0067] In some optional embodiments, during the process of continuously casting the refined molten steel to obtain the continuously cast slab, the temperature of the molten steel in the tundish is 1430°C to 1450°C.

[0068] Exemplarily, the temperature of the molten steel in the tundish is 1432°C, 1435°C, 1438°C, 1440°C, 1442°C, 1445°C, 1446°C, 1448°C, and 1450°C.

[0069] When the temperature of the molten steel in the tundish is 1430℃~1450℃, it can ensure that the macrostructure of the continuous casting ingot is excellent, there is no columnar crystal bridging, and the degree of center segregation is reduced.

[0070] In some optional embodiments, during the process of continuously casting the refined molten steel to obtain the continuously cast slab, the water nozzle insertion depth is 115 mm to 125 mm.

[0071] Exemplarily, the nozzle insertion depth is 115mm, 118mm, 120mm, 121mm, 122mm, 123mm, 124mm, and 125mm.

[0072] In some optional embodiments, during the process of continuously casting the refined molten steel to obtain the continuously cast slab, the water inlet inclination angle is downwardly inclined by 10° to 15°.

[0073] Exemplarily, the inclination angle of the water outlet is downwardly inclined at 10°, 11°, 12°, 13°, 14°, or 15°.

[0074] When the nozzle insertion depth is 115mm~125mm and the nozzle inclination is 10°~15° downward, it can ensure that during the continuous casting process, the molten steel flow field in the continuous casting crystallizer is reasonably distributed, there is no dead zone, the temperature gradient is appropriate, and stable continuous casting and multi-furnace continuous casting are achieved.

[0075] By controlling the molten steel temperature in the tundish, the nozzle insertion depth and the nozzle inclination angle in the continuous casting process within the above-mentioned appropriate ranges, the yield rate of heat-resistant non-magnetic steel can be effectively improved and the production efficiency can be improved.

[0076] In some optional embodiments, in the process of heating the continuous casting slab to obtain the heated continuous casting slab, the solution treatment temperature of the continuous casting slab is 1160℃~1170℃, the furnace outlet temperature is 1180℃~1200℃, and the heating time is 1.25min / mm~1.45min / mm.

[0077] In the process of heating the continuous casting slab to obtain the heated continuous casting slab, using a higher solution treatment temperature and a furnace discharge temperature for the continuous casting slab can reduce the rolling force in the subsequent rolling process of the continuous casting slab; using a longer heating time for the continuous casting slab, thereby reducing the heating rate of the continuous casting slab, to ensure that no thermal cracks are generated during the heating process of the continuous casting slab.

[0078] In some optional embodiments, during the process of rolling the heated continuous casting slab to obtain high manganese and high aluminum heat-resistant non-magnetic steel, the starting rolling temperature of the heated continuous casting slab is 1100℃~1150℃, the final rolling temperature is 800℃~950℃, and the rolling thickness is 4mm~25mm.

[0079] In some optional embodiments, after the step of rolling the heated continuous casting slab to obtain the high manganese and high aluminum heat-resistant non-magnetic steel, the step includes coiling the high manganese and high aluminum heat-resistant non-magnetic steel to obtain the coiled high manganese and high aluminum heat-resistant non-magnetic steel.

[0080] In some optional embodiments, the coiling temperature is 500°C to 650°C.

[0081] Exemplarily, the coiling temperature can be 500°C, 530°C, 540°C, 541°C, 542°C, 543°C, 544°C, 545°C, 550°C, 570°C, 575°C, 580°C, 581°C, 582°C, 583°C, 584°C, 585°C, 590°C, 600°C, 610°C, 620°C, 621°C, 622°C, 623°C, 624°C, 625°C, 630°C, 640°C, and 650°C.

[0082] Controlling the coiling temperature within the range of 500℃~650℃ can promote the precipitation of V and Ti carbides, achieve precipitation strengthening, and further improve the heat resistance of steel.

[0083] In some optional embodiments, the step of coiling the high manganese and high aluminum heat-resistant non-magnetic steel to obtain the coiled high manganese and high aluminum heat-resistant non-magnetic steel includes air cooling the coiled high manganese and high aluminum heat-resistant non-magnetic steel.

[0084] The embodiment of the present application provides an application of the high manganese and high aluminum heat-resistant non-magnetic steel obtained by the above-mentioned preparation method of the high manganese and high aluminum heat-resistant non-magnetic steel, and the application is at least selected from the following:

[0085] (1) Application in the preparation of submerged arc furnace parts;

[0086] (2) Application in the preparation of nuclear power equipment parts;

[0087] (3) Application in the preparation of power station unit components.

[0088] Example

[0089] The following examples describe the disclosure of the present application in more detail, and these examples are for illustrative purposes only, as various modifications and variations within the scope of the disclosure of the present application are apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by mass, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and the instruments used in the examples are commercially available.

[0090] Example 1

[0091] A method for preparing high manganese and high aluminum heat-resistant non-magnetic steel, comprising:

[0092] (1) Smelting, converter + LF refining furnace, electrolytic manganese is added during the converter steelmaking process, so that the Mn content of the molten steel after the converter is 16%; then manganese alloy, ferrosilicon, aluminum block, molybdenum block, tungsten alloy, nitriding and ferrotitanium are added in the LF refining stage, so that the Mn content of the molten steel is 23.3%, the Si content is 1.02%, the Al content is 2.96%, the Mo content is 0.89%, and the W content is 0.52%.

[0093] (2) Continuous casting: During the continuous casting process, the temperature of the molten steel in the tundish was 1446°C, the nozzle insertion depth was 122 mm, and the nozzle inclination angle was 12° downward.

[0094] (3) Heating: the solution temperature of the slab is 1176° C., the furnace temperature is 1197° C., and the heating time is 1.45 min / mm.

[0095] (4) Rolling: the slab rolling temperature after heating is 1141°C, the final rolling temperature is 937°C, the rolling thickness is 6 mm, the coiling temperature is 622°C, and the slab is air-cooled after coiling.

[0096] Figure 1 Shown is a schematic diagram of the slab of high manganese and high aluminum heat-resistant non-magnetic steel prepared in Example 1.

[0097] Example 2

[0098] A method for preparing high manganese and high aluminum heat-resistant non-magnetic steel, comprising:

[0099] (1) Smelting, converter + LF refining furnace, electrolytic manganese is added during the converter steelmaking process to make the Mn content of the molten steel after the converter station 15%; then manganese alloy, ferrosilicon, aluminum block, molybdenum block, tungsten alloy, nitriding and ferrotitanium are added in the LF refining stage to make the Mn content of the molten steel 24.6%, Si content 0.96%, Al content 3.11%, Mo content 0.66%, W content 0.49%.

[0100] (2) Continuous casting: During the continuous casting process, the temperature of the molten steel in the tundish was 1442°C, the nozzle insertion depth was 125 mm, and the nozzle inclination angle was 12° downward.

[0101] (3) Heating: the solution temperature of the slab is 1168° C., the furnace temperature is 1185° C., and the heating time is 1.37 min / mm.

[0102] (4) Rolling: the slab rolling temperature after heating is 1136°C, the final rolling temperature is 883°C, the rolling thickness is 16 mm, the coiling temperature is 584°C, and the slab is air-cooled after coiling.

[0103] Figure 2 Shown is a crystallizer temperature distribution cloud diagram taken at the production site of Example 2.

[0104] Example 3

[0105] A method for preparing high manganese and high aluminum heat-resistant non-magnetic steel, comprising:

[0106] (1) Smelting, converter + LF refining furnace, electrolytic manganese is added during the converter steelmaking process, so that the Mn content of the molten steel after the converter is 14%; then manganese alloy, ferrosilicon, aluminum block, molybdenum block, tungsten alloy, nitriding and ferrotitanium are added in the LF refining stage, so that the Mn content of the molten steel is 22.8%, the Si content is 1.15%, the Al content is 2.78%, the Mo content is 0.62%, and the W content is 0.61%.

[0107] (2) Continuous casting: During the continuous casting process, the temperature of the molten steel in the tundish was 1438°C, the nozzle insertion depth was 121 mm, and the nozzle inclination angle was 15° downward.

[0108] (3) Heating: the solution temperature of the slab is 1163° C., the furnace temperature is 1180° C., and the heating time is 1.39 min / mm.

[0109] (4) Rolling: the slab rolling temperature after heating is 1132°C, the final rolling temperature is 839°C, the rolling thickness is 25 mm, the coiling temperature is 541°C, and the slab is air-cooled after coiling.

[0110] Figure 3 Shown is a schematic diagram of the finished steel plate prepared in Example 3.

[0111] The chemical composition of the high manganese and high aluminum heat-resistant non-magnetic steel of Example 1-3 is shown in Table 1.

[0112] Table 1: Chemical element mass fractions / wt.% of Examples 1-3

[0113] Serial number C Si Mn P S Al Mo W V Ti Example 1 0.21 1.02 23.3 0.009 0.009 2.96 0.89 0.52 0.16 0.08 Example 2 0.18 0.96 24.6 0.016 0.012 3.11 0.66 0.49 0.18 0.05 Example 3 0.24 1.15 22.8 0.012 0.010 2.78 0.62 0.61 0.13 0.14

[0114] The process parameters of each step of high manganese and high aluminum heat-resistant non-magnetic steel in Examples 1-3 are shown in Table 2.

[0115] Table 2: Process parameters of each step of Examples 1-3

[0116]

[0117] Performance Testing

[0118] The steel samples of Examples 1-3 were subjected to performance tests including yield strength, tensile strength, elongation after fracture, -20°C impact energy (longitudinal), relative magnetic permeability, and grain size. The test results are shown in Table 3 below.

[0119] Table 3: Product performance of Examples 1-3

[0120]

[0121] It can be concluded from Table 3 that the yield strength R of the high manganese and high aluminum heat-resistant non-magnetic steel prepared in Examples 1-3 of the present application at 20°C to 25°C is p0.2 ≥400MPa, tensile strength R m ≥700MPa, elongation after fracture A≥30%, -20℃ KV2 impact (standard sample)≥180J, relative magnetic permeability≤1.002, grain size is 7~9;

[0122] Yield strength R at 400℃~700℃ p0.2 ≥300MPa, tensile strength R m ≥600MPa, elongation after fracture A≥30%, relative magnetic permeability measured after cooling from 400℃~700℃ to 20℃~25℃≤1.005. The above description shows that the high manganese and high aluminum heat-resistant non-magnetic steel prepared by the preparation method of the high manganese and high aluminum heat-resistant non-magnetic steel of the present application has good mechanical properties and low relative magnetic permeability.

[0123] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A high manganese and high aluminum heat-resistant non-magnetic steel, characterized in that: The high manganese and high aluminum heat-resistant non-magnetic steel comprises, by mass percentage: Si: 0.50%~1.50%, Al: 2.00%~4.00%, Mo: 0.20%~2.00%, W: 0.25%~0.90%, C: 0.10%~0.30%, Mn: 21.0%~27.0%, P≤0.025%, S≤0.020%, V: 0.06%~0.20%, Ti: 0.02%~0.15%, the balance is Fe and unavoidable impurities.

2. The high manganese and high aluminum heat-resistant non-magnetic steel according to claim 1, characterized in that: The yield strength R of the high manganese and high aluminum heat-resistant non-magnetic steel at 20°C to 25°C p0.2 ≥400Mpa; tensile strength R m ≥700MPa; elongation after fracture A≥30%; impact energy KV2 at -20℃≥180J; grain size is 7 to 9; relative magnetic permeability ≤1.

002.

3. The high manganese and high aluminum heat-resistant non-magnetic steel according to claim 1, characterized in that: The yield strength R of the high manganese and high aluminum heat-resistant non-magnetic steel at 400°C to 700°C is p0.2 ≥300MPa; tensile strength R m ≥600MPa, elongation after fracture A≥30%; the relative magnetic permeability of the high manganese and high aluminum heat-resistant non-magnetic steel after cooling from 400℃~700℃ to 20℃~25℃ is ≤1.

005.

4. A method for preparing high manganese and high aluminum heat-resistant non-magnetic steel, characterized in that: include: Refining the crude molten steel to obtain refined molten steel, wherein the refined molten steel contains, by mass percentage, 21.0% to 27.0% Mn, 0.70% to 1.20% Si, 2.50% to 3.50% Al, 0.50% to 1.20% Mo, and 0.30% to 0.80% W; Continuously casting the refined molten steel to obtain a continuously cast slab; heating the continuous casting slab to obtain a heated continuous casting slab; The heated continuous casting slab is rolled to obtain high manganese and high aluminum heat-resistant non-magnetic steel.

5. The preparation method according to claim 4, characterized in that: In the process of continuously casting the refined molten steel to obtain the continuously cast slab, the temperature of the molten steel in the tundish is 1430°C to 1450°C; the insertion depth of the water nozzle is 115mm to 125mm; and the inclination angle of the water nozzle is downwardly inclined by 10° to 15°.

6. The preparation method according to claim 4, characterized in that: In the process of heating the continuous casting slab to obtain the heated continuous casting slab, the solution treatment temperature of the continuous casting slab is 1160°C to 1170°C, the furnace discharge temperature is 1180°C to 1200°C, and the heating time is 1.25min / mm to 1.45min / mm.

7. The preparation method according to claim 4, characterized in that: In the process of rolling the heated continuous casting slab to obtain high manganese and high aluminum heat-resistant non-magnetic steel, the starting rolling temperature of the heated continuous casting slab is 1100°C to 1150°C, the final rolling temperature is 800°C to 950°C, and the rolling thickness is 4mm to 25mm.

8. The preparation method according to claim 4, characterized in that: The step of rolling the heated continuous casting slab to obtain the high manganese and high aluminum heat-resistant non-magnetic steel includes coiling the high manganese and high aluminum heat-resistant non-magnetic steel to obtain the coiled high manganese and high aluminum heat-resistant non-magnetic steel; The coiling temperature is 500°C to 650°C.

9. The preparation method according to claim 8, characterized in that: The step of refining the crude molten steel to obtain the refined molten steel includes, before that, smelting the raw molten steel in a converter to obtain the crude molten steel; and / or, The step of coiling the high manganese and high aluminum heat-resistant non-magnetic steel to obtain the coiled high manganese and high aluminum heat-resistant non-magnetic steel includes air cooling the coiled high manganese and high aluminum heat-resistant non-magnetic steel.

10. An application of high manganese and high aluminum heat-resistant non-magnetic steel obtained by the preparation method according to any one of claims 4 to 9, characterized in that: The application is at least one selected from the following: (1) Application in the preparation of submerged arc furnace parts; (2) Application in the preparation of nuclear power equipment parts; (3) Application in the preparation of power station unit components.

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