Preparation method of high-manganese high-aluminum non-magnetic steel and high-manganese high-aluminum non-magnetic steel

Abstract

The invention discloses a preparation method of high-manganese high-aluminum non-magnetic steel and the high-manganese high-aluminum non-magnetic steel, and the method comprises the following steps: carrying out three-stage heating on a continuous casting slab to obtain a heated slab, the method comprises the following steps: (1) a continuous casting slab is subjected to continuous casting at a preheating section, a heating section and a soaking section, and the heating section and the soaking section meet the following conditions: (1) the width of the continuous casting slab is 950-1250 mm, the highest temperature of the heating section is 1210-1230 DEG C, and the time of the heating section is 60-90 minutes; the temperature of the soaking section is 1190-1210 DEG C, and the time of the soaking section is 30-60 minutes; (2) the width of the continuous casting slab is 1250-1850 mm, the highest temperature of a heating section is 1240-1260 DEG C, the time of the heating section is 60-90 min, the temperature of a soaking section is 1220-1240 DEG C, and the time of the soaking section is 30-60 min; (3) the width of the continuous casting slab ranges from 1850 mm to 2100 mm, the highest temperature of a heating section ranges from 1270 DEG C to 1290 DEG C, the time of the heating section ranges from 60 min to 90 min, the temperature of a soaking section ranges from 1240 DEG C to 1260 DEG C, and the time of the soaking section ranges from 30 min to 60 min; and the heated plate blank is rolled and coiled through a hot continuous rolling mill, and the high-manganese high-aluminum non-magnetic steel is obtained. The method provided by the invention can realize efficient production and stable performance.

Description

Technical Field

[0001] The present application belongs to the technical field of steel smelting, and specifically relates to a preparation method of high-manganese and high-aluminum non-magnetic steel and high-manganese and high-aluminum non-magnetic steel. Background Art

[0002] High manganese and high aluminum non-magnetic steel is generally austenitic steel of Fe-Mn-Al-C series. It has stable metallographic structure, excellent mechanical properties, low magnetic permeability and high resistivity, and extremely small conduction loss in magnetic field. It is mainly used to manufacture transformers and various engineering structures, such as nuclear energy, petroleum industry, ships, etc.

[0003] Due to the high alloy content in high manganese and high aluminum non-magnetic steel, the Mn content exceeds 20%, the Al content exceeds 1%, and the rolling force is large. At present, high manganese and high aluminum non-magnetic steel is mainly produced by die casting, single plate rolling and continuous casting, single plate rolling.

[0004] When single plate is rolled, because of its ability to expand laterally, there are not many requirements for the specifications of the continuous casting billet. In addition, single plate rolling adopts medium and thick plate rolling mills with large rolling force, and the slab can be heated at a lower temperature. However, the rolling speed of single plate is slow, the efficiency is low, and the temperature drop of the steel plate is large, which can easily cause edge cracks or edge rot. In addition, iron oxide scale is easily generated on the surface of high manganese and high aluminum non-magnetic steel plates. In addition, the hot rolling rate of single plate is slow, and the oxide layer is generated on the surface of the steel plate, which ultimately results in poor surface quality of the finished steel plate. In addition, the high manganese and high aluminum non-magnetic steel rolled by single plate has coarse grains, low yield strength and tensile strength, which can hardly meet the use requirements of high-strength non-magnetic steel, and therefore it is in urgent need of improvement. Summary of the invention

[0005] In view of this, the present application provides a preparation method of high manganese and high aluminum non-magnetic steel and high manganese and high aluminum non-magnetic steel, aiming to provide a preparation method that can achieve fast and efficient production and stable product performance. The present application provides a high manganese and high aluminum non-magnetic steel with uniform and stable performance and good surface quality.

[0006] In a first aspect, an embodiment of the present application provides a method for preparing high manganese and high aluminum non-magnetic steel, comprising:

[0007] The continuously cast slab is subjected to three-stage heating to obtain a heated slab, wherein the three-stage heating includes, in order of time, a preheating section, a heating section, and a soaking section, and the heating section and the soaking section include any one or more of 1) to 3) according to the thickness of the continuously cast slab:

[0008] 1) When the width of the continuous casting slab is 950-1250 mm, the maximum temperature of the heating section is 1210-1230° C., and the heating time is 60-90 min; the temperature of the soaking section is 1190-1210° C., and the soaking time is 30-60 min;

[0009] 2) When the width of the continuous casting slab is 1250-1850 mm, the maximum temperature of the heating section is 1240-1260° C., the heating time is 60-90 min, the soaking section temperature is 1220-1240° C., and the soaking time is 30-60 min;

[0010] 3) When the width of the continuous casting slab is 1850-2100 mm, the maximum temperature of the heating section is 1270-1290° C., the heating time is 60-90 min, the temperature of the soaking section is 1240-1260° C., and the soaking time is 30-60 min;

[0011] The heated slab is rolled and coiled by a hot rolling mill to obtain the high manganese and high aluminum non-magnetic steel.

[0012] According to an embodiment of one aspect of the present application, the high manganese and high aluminum non-magnetic steel has the following components by weight: C: 0.10%-0.30%, Mn: 21.0%-27.0%, Si: 0.10%-0.50%, Al:

[0013] 1.80%-2.80%, P≤0.025%, S≤0.020%, V: 0.05%-0.15%, Ti: 0.02%-0.10%, the balance is Fe and unavoidable impurities.

[0014] According to an embodiment of one aspect of the present application, the temperature of the preheating section is ≤750°C, and the time of the preheating section is 90 to 120 minutes.

[0015] According to an embodiment of one aspect of the present application, the rolling includes rough rolling, the starting rolling temperature of the rough rolling is 1120-1220°C, the final rolling thickness of the rough rolling is 40-60 mm, and the final rolling temperature of the rough rolling is 980-1160°C.

[0016] According to an embodiment of one aspect of the present application, the rolling includes finishing rolling, the finishing rolling adopts 7-continuous rolling, the final rolling thickness of the finishing rolling is 3 to 25 mm, and the starting rolling temperature of the finishing rolling is

[0017] The final rolling temperature of the finishing rolling is 800-1020°C.

[0018] According to an embodiment of one aspect of the present application, before the coiling, the method includes laminar cooling, and the laminar cooling makes the terminal temperature of the continuous casting slab 300-450°C, and the cooling rate of the laminar cooling is 15-30°C / s.

[0019] According to an embodiment of one aspect of the present application, the maximum weight of the continuously cast slab during coiling is 38 t, and the length of the continuously cast slab is ≤11000 mm.

[0020] According to an embodiment of one aspect of the present application, after the coiling, the method further includes: air cooling the coiled steel coil.

[0021] In a second aspect, an embodiment of the present application provides a high manganese and high aluminum non-magnetic steel, which is prepared by the preparation method of the first aspect.

[0022] According to an embodiment of one aspect of the present application, the yield strength R of the high manganese and high aluminum non-magnetic steel at room temperature is p0.2 ≥350MPa, tensile strength R m ≥650MPa, elongation after fracture A≥40%, -20℃ KV2 impact energy≥150J, grain size 7~9, relative magnetic permeability≤1.01.

[0023] This application has at least the following beneficial effects:

[0024] The method provided in this application uses a suitable heating process and a hot rolling mill for rolling. The combination of the two produces high manganese and high aluminum non-magnetic steel with good surface quality, uniform and stable performance, and excellent mechanical properties; compared with the related technology using single plate rolling for rolling, the production efficiency is improved. Generally speaking, the rolling force of the hot rolling mill is greater than that of the single plate rolling mill, and the temperature sensitivity is strong; therefore, the method of this application can effectively improve the problems of low single plate rolling efficiency, poor surface quality, and low mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] Figure 1 A micrograph of the high manganese and high aluminum non-magnetic steel according to an embodiment of the present application is shown.

[0027] Figure 2 A micrograph of the high manganese and high aluminum non-magnetic steel of the comparative example of the present application is shown.

[0028] Figure 3 The surface appearance of the high manganese and high aluminum non-magnetic steel according to the embodiment of the present application is shown.

[0029] Figure 4 The surface appearance of the high manganese and high aluminum non-magnetic steel of the comparative example of the present application is shown. DETAILED DESCRIPTION

[0030] 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.

[0031] 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.

[0032] In the description of the present application, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number, and the “multiple” in “one or more” means two or more than two.

[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 Al content in high manganese and high aluminum non-magnetic steel plates is high, and long-term high-temperature heating can easily cause surface nitriding and form a large amount of AlN. A large number of corner, surface and internal cracks appear in the slab during the rolling process, which deteriorates the surface and internal quality of the steel and seriously affects the product quality. In the related art, single plate rolling is used for rolling, which has many defects. It has been found that a hot rolling process can be used. During use, it was found that the maximum rolling load capacity of each frame in the hot rolling process is lower than that of the medium and thick plate rolling mill. It has been found that in order to improve the surface quality and mechanical properties of high manganese and high aluminum non-magnetic steel products, while improving production efficiency and reducing production costs, it is necessary to strictly control the temperature of the continuous casting billet before the hot rolling process, which has high requirements. In addition, the lateral expansion capacity of the continuous rolling unit is almost negligible, so the specifications of the continuous casting billet must be strict, that is, the width of the continuous casting billet is required to be almost the same as the final width of the steel plate.

[0035] In summary, in order to prepare high manganese and high aluminum non-magnetic steel by continuous casting + hot rolling process, more stringent hot rolling process parameters should be formulated according to the final product specifications.

[0036] High manganese and high aluminum non-magnetic steel plates, among which non-magnetic steel plates (non-magnetic steel), also known as anti-magnetic steel, have extremely weak magnetism, close to non-magnetic materials, but are not absolutely non-magnetic. Non-magnetic steel has relative magnetic permeability. Relative magnetic permeability (relative permeability, μr) is the ratio of the magnetic permeability of a material to the magnetic permeability of a vacuum, which is used to measure the magnetism of a material. For non-magnetic steel: The relative magnetic permeability of non-magnetic steel is usually close to 1 (between 1 and 1.02), which is very close to the relative magnetic permeability of vacuum or air, and is usually called "non-magnetic".

[0037] Preparation method of high manganese and high aluminum non-magnetic steel

[0038] In a first aspect, an embodiment of the present application provides a method for preparing high manganese and high aluminum non-magnetic steel, comprising:

[0039] The continuously cast slab is subjected to three-stage heating to obtain a heated slab, wherein the three-stage heating includes, in order of time, a preheating section, a heating section, and a soaking section, and the heating section and the soaking section include any one or more of 1) to 3) according to the thickness of the continuously cast slab:

[0040] 1) When the width of the continuous casting slab is 950-1250 mm, the maximum temperature of the heating section is 1210-1230° C., and the heating time is 60-90 min; the temperature of the soaking section is 1190-1210° C., and the soaking time is 30-60 min;

[0041] 2) When the width of the continuous casting slab is 1250-1850 mm, the maximum temperature of the heating section is 1240-1260° C., the heating time is 60-90 min, the soaking section temperature is 1220-1240° C., and the soaking time is 30-60 min;

[0042] 3) When the width of the continuous casting slab is 1850-2100 mm, the maximum temperature of the heating section is 1270-1290° C., the heating time is 60-90 min, the temperature of the soaking section is 1240-1260° C., and the soaking time is 30-60 min;

[0043] The heated slab is rolled and coiled by a hot rolling mill to obtain the high manganese and high aluminum non-magnetic steel.

[0044] According to the embodiment of the present application, high manganese and high aluminum non-magnetic steel is an austenitic steel containing a high content of manganese (Mn) and aluminum (Al), which can achieve a stable austenite phase. Studies have found that during the heating process, especially at high temperatures (such as above 800°C), austenite is easily decomposed or undergoes phase transformation at high temperatures, transforming into other phases (such as ferrite, pearlite or martensite), which will change the microstructure of the material, such as grain size, etc., indicating that high manganese and high aluminum non-magnetic steel is temperature sensitive. This feature needs to be considered during the rolling process to reduce its impact on the magnetism and other mechanical properties of the continuous casting slab.

[0045] In the related art, the single plate rolling efficiency is low and the compression ratio is relatively small. When the hot rolling mill of the present application is used for rolling, it is easy to cause changes in the grains of the high manganese and high aluminum non-magnetic steel and the transformation of the metallographic structure, which will affect the performance of the high manganese and high aluminum non-magnetic steel. Due to the high alloy content of high manganese and high aluminum non-magnetic steel, the rolling force of the same specification is significantly increased compared with that of low alloy steel. In order to reduce the rolling force as much as possible and ensure the smooth continuous rolling, a specific heating process is required to improve the surface quality and performance uniformity of the manganese and high aluminum non-magnetic steel. The present application adopts the above-mentioned three-stage heating, and the heating section and the soaking section adopt the above-mentioned process parameters according to the slab width.

[0046] Generally speaking, the maximum rolling force that a hot rolling mill can withstand is ≤50,000 kN, and the maximum rolling force that a single plate rolling mill can withstand is generally ≤120,000 kN. Therefore, when rolling the same steel plate, the rolling force exerted on the hot rolling mill is greater than that exerted on the single plate rolling mill, and the temperature sensitivity is strong. Therefore, the method of the present application can effectively improve the problems of low single plate rolling efficiency, poor surface quality, and low mechanical properties.

[0047] In some optional embodiments, before the continuous casting slab is subjected to three-stage heating to obtain the heated slab, the method further comprises: smelting and continuously casting the molten steel. For example, a continuous casting slab with a specification of 230 mm×(900-2100 mm)×(7000-11000 mm) can be obtained through the BOF-LF-RH-continuous casting production process.

[0048] In some optional embodiments, the high manganese and high aluminum non-magnetic steel has the following components in weight percentage: C: 0.10%-0.30%, Mn: 21.0%-27.0%, Si: 0.10%-0.50%, Al: 1.80%-2.80%, P≤0.025%, S≤0.020%, V: 0.05%-0.15%, Ti: 0.02%-0.10%, and the remainder is Fe and unavoidable impurities.

[0049] According to the embodiment of the present application, the Al content in the continuous casting slab is high. During the heating process, the surface layer of the continuous casting slab infiltrates N to form AlN, which can easily cause peeling during the rolling process. Therefore, in order to ensure the surface quality of the steel coil, the above-mentioned three-stage heating is adopted, and strict control is performed for different temperatures and times.

[0050] In some optional embodiments, the temperature of the preheating section is ≤750°C, and the preheating time is 90 to 120 minutes. The continuous casting slab of high manganese and high aluminum non-magnetic steel has a high alloy content in its chemical composition and a large thermal expansion coefficient, but slow heat transfer. The preheating section can achieve slow preheating, ensure uniform preheating of the continuous casting slab, and is conducive to the uniform performance of manganese and high aluminum non-magnetic steel.

[0051] In some optional embodiments, the rolling includes rough rolling, the starting rolling temperature of the rough rolling is 1120-1220° C., the final rolling thickness of the rough rolling is 40-60 mm, and the final rolling temperature of the rough rolling is 980-1160° C. The rough rolling process can refine the grains in the continuous casting slab, and improve the strength and performance uniformity of the high manganese and high aluminum non-magnetic steel.

[0052] Generally speaking, rough rolling can be carried out by large reduction rolling to break the austenite structure and form a recrystallized structure.

[0053] In some optional embodiments, the rolling includes finishing rolling, the finishing rolling adopts 7-roll rolling, the final rolling thickness of the finishing rolling is 3-25 mm, the starting rolling temperature of the finishing rolling is 960-1140° C., and the final rolling temperature of the finishing rolling is 800-1020° C. The above finishing rolling process can make the austenite grains in the continuous casting slab broken and recrystallized again, so as to fully refine the grains and further improve the product strength and performance uniformity.

[0054] In some optional embodiments, before the coiling, the method includes laminar cooling, and the laminar cooling makes the terminal temperature of the continuous casting slab be 300-450° C. The laminar cooling method can save energy and improve production efficiency, avoid cracks and breaks during the coiling process, and improve the surface quality of the steel coil.

[0055] In some optional embodiments, the maximum weight of the continuous casting slab during coiling is 38t, and the length of the continuous casting slab is ≤11000mm. Generally speaking, the size of the continuous casting slab can be: 230mm×(950~2100mm)×(7000~11000mm). Considering the length of the horizontal line after cross-cutting after coiling, the length of the steel coil after hot rolling and coiling is ≥70m, and the length of the continuous casting slab is generally not less than 7000mm.

[0056] In some optional embodiments, after coiling, the method further comprises: air cooling the coiled steel coil, so as to utilize the residual heat after coiling to promote the precipitation of second phase particles such as VC and TiC in the structure, thereby further improving the strength of the steel plate.

[0057] High manganese and high aluminum non-magnetic steel

[0058] In a second aspect, an embodiment of the present application provides a high manganese and high aluminum non-magnetic steel, which is prepared by the preparation method of the first aspect.

[0059] In some optional embodiments, the yield strength R of the high manganese and high aluminum non-magnetic steel at room temperature is p0.2 ≥350MPa, tensile strength R m ≥650MPa, elongation after fracture A≥40%, -20℃ KV2 impact energy (standard sample)≥150J, relative magnetic permeability≤1.01.

[0060] In some optional embodiments, grain grading is performed according to GB / T 6394-2017, and the grains in the high manganese and high aluminum non-magnetic steel are graded from 7 to 9.

[0061] Example

[0062] The following examples describe the disclosure of the present application in more detail, and these examples are intended for illustrative purposes only, as it will be apparent to those skilled in the art that various modifications and variations may be made within the scope of the disclosure of the present application. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0063] Example 1

[0064] This embodiment provides a method for preparing 6 mm thick high manganese and high aluminum non-magnetic steel. The chemical composition of the continuous casting slab of the high manganese and high aluminum non-magnetic steel is shown in Table 1. The preparation process of the high manganese and high aluminum non-magnetic steel is as follows:

[0065] Smelting and continuous casting: Through the BOF-LF-RH-continuous casting production process, the continuous casting slab with the specification of 230mm×2050mm(width)×8000mm is obtained;

[0066] Heating and rolling of continuous casting slabs: After the high manganese and high aluminum non-magnetic steel continuous casting slabs are put into the furnace, they are heated in three stages:

[0067] The preheating temperature is 720℃ and the preheating time is 100min;

[0068] The maximum temperature of the heating section is 1270°C, the heating time is 85 minutes, the temperature of the soaking section is 1250°C, and the soaking time is 40 minutes.

[0069] Next, a hot rolling mill is used for rough rolling, the rough rolling start temperature is 1215°C, the rough rolling final thickness is 45mm, and the rough rolling final temperature is 1140°C.

[0070] Finishing rolling adopts 7 consecutive rollings, the final rolling thickness is 6mm, the finishing rolling start temperature is 1100℃, and the finishing rolling final temperature is 860℃.

[0071] Coiled, coiled at 360°C, air cooled after coiled.

[0072] Example 2

[0073] This embodiment provides a method for preparing 6mm thick high manganese and high aluminum non-magnetic steel. The chemical composition of the continuous casting slab of the high manganese and high aluminum non-magnetic steel is shown in Table 1. The preparation process of the high manganese and high aluminum non-magnetic steel in this embodiment is as follows:

[0074] Smelting and continuous casting: Through the BOF-LF-RH-continuous casting production process, the continuous casting slab with the specification of 230mm×1650mm(width)×10000mm is obtained;

[0075] Heating and rolling of continuous casting slabs: After the high manganese and high aluminum non-magnetic steel continuous casting slabs are put into the furnace, they are heated in three stages:

[0076] The temperature of the preheating section is 700°C and the preheating time is 100 minutes;

[0077] The maximum temperature of the heating section is 1240°C, the heating time is 90 minutes, the temperature of the soaking section is 1220°C, and the soaking time is 50 minutes;

[0078] Next, a hot rolling mill is used for rough rolling, the starting temperature of the rough rolling is 1170°C, the final thickness of the rough rolling is 42 mm, and the final temperature of the rough rolling is 1050°C.

[0079] Finishing rolling adopts 7 consecutive rollings, the final rolling thickness is 6mm, the finishing rolling start temperature is 1010℃, and the finishing rolling final temperature is 950℃.

[0080] Coiled at a temperature of 320°C and air cooled after coiling.

[0081] Example 3

[0082] This embodiment provides a method for preparing 8mm thick high manganese and high aluminum non-magnetic steel. The chemical composition of the continuous casting slab of the high manganese and high aluminum non-magnetic steel is shown in Table 1. The preparation process of the high manganese and high aluminum non-magnetic steel in this embodiment is as follows:

[0083] Smelting and continuous casting: Through the BOF-LF-RH-continuous casting production process, continuous casting slabs with specifications of 230mm×1200mm (width)×10000mm are obtained;

[0084] Heating and rolling of continuous casting slabs: After the high manganese and high aluminum non-magnetic steel continuous casting slabs are put into the furnace, they are heated in three stages:

[0085] The temperature of the preheating section is 700°C and the preheating time is 100 minutes;

[0086] The maximum temperature of the heating section is 1180°C, the heating time is 70 minutes, the temperature of the soaking section is 1150°C, and the soaking time is 50 minutes;

[0087] Next, a hot rolling mill is used for rough rolling, the rough rolling start temperature is 1125°C, the rough rolling final thickness is 45, and the rough rolling final temperature is 990°C.

[0088] Finishing rolling adopts 7 consecutive rolling, the final rolling thickness is 8mm, the finishing rolling starting temperature is 970℃, and the finishing rolling final rolling temperature is 840℃.

[0089] Coiled at a temperature of 340°C and air cooled after coiling.

[0090] Table 1 Chemical composition of continuous casting slab (in mass percentage, the balance in the composition is Fe and unavoidable impurity elements)

[0091]

[0092] Example 4

[0093] The difference between this embodiment and embodiment 1 is that the temperature of the preheating section is 740° C. and the preheating time is 94 minutes.

[0094] Example 5

[0095] The difference between this embodiment and embodiment 1 is that the maximum temperature of the heating section is 1280° C., the time of the heating section is 80 minutes, the temperature of the soaking section is 1240° C., and the time of the soaking section is 35 minutes.

[0096] Example 6

[0097] The difference between this embodiment and embodiment 2 is that the maximum temperature of the heating section is 1260° C., the time of the heating section is 80 minutes, the temperature of the soaking section is 1240° C., and the time of the soaking section is 40 minutes.

[0098] Example 7

[0099] The difference between this embodiment and embodiment 2 is that the maximum temperature of the heating section is 1250° C., the time of the heating section is 75 minutes, the temperature of the soaking section is 1230° C., and the time of the soaking section is 45 minutes.

[0100] Comparative Example 1

[0101] The difference between this embodiment and embodiment 1 is that the maximum temperature of the heating section is 1300° C., the time of the heating section is 60 minutes, the temperature of the soaking section is 1220° C., and the time of the soaking section is 45 minutes.

[0102] Comparative Example 2

[0103] The difference between this comparative example and Example 2 is that the maximum temperature of the heating section is 1310° C., the time of the heating section is 78 minutes, the temperature of the soaking section is 1200° C., and the time of the soaking section is 40 minutes.

[0104] Comparative Example 3

[0105] The difference between this comparative example and Example 3 is that the maximum temperature of the heating section is 1298° C., and the time of the heating section is 90 min; the temperature of the soaking section is 1180° C., and the time of the soaking section is 50 min.

[0106] Test Section

[0107] The appearance of the high manganese and high aluminum non-magnetic steels prepared in the examples and comparative examples was inspected, and it was found that the appearance of examples 1-9 was good, without peeling or cracking, while comparative examples 1-3 had a certain peeling phenomenon.

[0108] The steel coils of high manganese and high aluminum non-magnetic steel prepared in the embodiments and comparative examples were sampled at their head (10m from the end), middle (position extending 20m from the midpoint in the length direction) and tail (10m from the end) along the length direction; the steel coils of high manganese and high aluminum non-magnetic steel prepared in the embodiments and comparative examples were sampled at the left side (10mm from the edge), middle area (2mm in the middle) and right side (10mm) of any section of the steel coil along the width direction; the tensile strength and ductility were tested according to GB / T 228.1-2010 standard, the low temperature impact toughness was tested according to GB / T 229-2020, and the relative magnetic permeability was tested according to ASTM A342-14 standard.

[0109] Table 1 Test results of high manganese and high aluminum non-magnetic steel in the embodiment and comparative example.

[0110]

[0111]

[0112]

[0113] The above measured performance parameters are taken as average values.

[0114] In addition, the product has been tested for performance. The yield strength R p0.2 =396MPa, tensile strength R m =740MPa, elongation after fracture A=53%, -20℃ KV2 impact (converted to standard sample)=212J, grain size 9, relative magnetic permeability=1.003. Yield strength R of high manganese and high aluminum non-magnetic steel at room temperature in Example 2 p0.2 =375MPa, tensile strength R m =722MPa, elongation after fracture A=55%, -20℃ KV2 impact (converted to standard sample)=208J, grain size 8.5, relative magnetic permeability=1.003. Yield strength R of high manganese and high aluminum non-magnetic steel at room temperature in Example 3 p0.2 =363MPa, tensile strength R m =709MPa, elongation after fracture A=54%, -20℃ KV2 impact (converted to standard sample)=211J, grain size level 9, relative magnetic permeability=1.002.

[0115] Figure 1 A micrograph of the high manganese and high aluminum non-magnetic steel according to an embodiment of the present application is shown. Figure 2 The micrograph of the high manganese and high aluminum non-magnetic steel of the comparative example of the present application is shown. Figure 1 and Figure 2 It can be seen that the method of the present application can refine the grains of high-manganese and high-aluminum non-magnetic steel and improve the performance uniformity of the steel plate.

[0116] Figure 3 The surface appearance of the high manganese and high aluminum non-magnetic steel according to the embodiment of the present application is shown. Figure 4 The surface appearance of the high manganese and high aluminum non-magnetic steel of the comparative example of the present application is shown. Figure 3 and Figure 4 It can be seen that the method of the application can remove the peeling phenomenon on the surface of the steel plate and improve the surface quality of the high-manganese and high-aluminum non-magnetic steel of the application.

[0117] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any familiarity with the present technology or replacement should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing high manganese and high aluminum non-magnetic steel, characterized in that: include: The continuously cast slab is subjected to three-stage heating to obtain a heated slab, wherein the three-stage heating includes, in order of time, a preheating section, a heating section, and a soaking section, and the heating section and the soaking section include any one or more of 1) to 3) according to the width of the continuously cast slab: 1) When the width of the continuous casting slab is 950-1250 mm, the maximum temperature of the heating section is 1210-1230° C., and the heating time is 60-90 min; the temperature of the soaking section is 1190-1210° C., and the soaking time is 30-60 min; 2) When the width of the continuous casting slab is 1250-1850 mm, the maximum temperature of the heating section is 1240-1260° C., the heating time is 60-90 min, the soaking section temperature is 1220-1240° C., and the soaking time is 30-60 min; 3) When the width of the continuous casting slab is 1850-2100 mm, the maximum temperature of the heating section is 1270-1290° C., the heating time is 60-90 min, the temperature of the soaking section is 1240-1260° C., and the soaking time is 30-60 min; The heated slab is rolled and coiled by a hot rolling mill to obtain the high manganese and high aluminum non-magnetic steel.

2. The preparation method according to claim 1, characterized in that: The components of the high manganese and high aluminum non-magnetic steel are as follows by weight: C: 0.10%-0.30%, Mn: 21.0%-27.0%, Si: 0.10%-0.50%, Al: 1.80%-2.80%, P≤0.025%, S≤0.020%, V: 0.05%-0.15%, Ti: 0.02%-0.10%, and the balance is Fe and unavoidable impurities.

3. The preparation method according to claim 1, characterized in that: The temperature of the preheating section is ≤750°C, and the time of the preheating section is 90 to 120 minutes.

4. The preparation method according to claim 1, characterized in that: The rolling includes rough rolling, the starting rolling temperature of the rough rolling is 1120-1220°C, the final rolling thickness of the rough rolling is 40-60mm, and the final rolling temperature of the rough rolling is 980-1160°C.

5. The preparation method according to claim 1, characterized in that: The rolling includes finishing rolling, the finishing rolling adopts 7 consecutive rolling, the final rolling thickness of the finishing rolling is 3-25 mm, the starting rolling temperature of the finishing rolling is 960-1140° C., and the final rolling temperature of the finishing rolling is 800-1020° C.

6. The preparation method according to claim 1, characterized in that: Before the coiling, the method includes laminar cooling, wherein the laminar cooling makes the terminal temperature of the continuous casting slab be 300-450° C., and the cooling rate of the laminar cooling is 15-30° C. / s.

7. The preparation method according to claim 1, characterized in that: The maximum weight of the continuous casting slab during coiling is 38t, and the length of the continuous casting slab is ≤11000mm.

8. The preparation method according to claim 1, characterized in that: After the coiling, the method further comprises: air cooling the coiled steel coil.

9. A high manganese and high aluminum non-magnetic steel, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 8.

10. The high manganese and high aluminum non-magnetic steel according to claim 9, characterized in that: The yield strength R of the high manganese and high aluminum non-magnetic steel at room temperature p0.2 ≥350MPa, tensile strength R m ≥650MPa, elongation after fracture A≥40%, -20℃ KV2 impact energy≥150J, grain size 7~9, relative magnetic permeability≤1.01.

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