An austenitic stainless steel and non-magnetic austenitic stainless steel pipe

Abstract

The present disclosure relates to the technical field of stainless steel materials, in particular to an austenitic stainless steel and a non-magnetic austenitic stainless steel pipe. The austenitic stainless steel contains the following components in mass percent: C: ≤0.03%, Si: ≤0.75%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the rest is Fe and unavoidable impurities; wherein a, b, c, d, e satisfy the following conditions: 0.25 ≤ a ≤ 1.75; 15 ≤ b ≤ 20; 10 ≤ c ≤ 15; 0.05 ≤ d ≤ 0.2; 0.25 ≤ e ≤ 1.75.

Description

Technical Field

[0001] This disclosure relates to the field of stainless steel materials technology, specifically to an austenitic stainless steel and a non-magnetic austenitic stainless steel pipe. Background Technology

[0002] Austenitic stainless steel, due to its excellent corrosion resistance, formability, and weldability, has become the mainstream material in pipe manufacturing and is widely used in industries such as petrochemicals, energy transportation, precision instruments, and medical devices. However, traditional austenitic stainless steel is prone to stress-induced martensitic transformation during cold working processes (such as cold rolling, cold drawing, and bending). This transformation leads to the following technical defects: First, the martensitic phase is ferromagnetic, causing the pipe to become magnetic, which cannot meet the stringent requirements of precision instruments, magnetic resonance imaging (MRI) equipment, and electronic devices for a non-magnetic environment. Second, a large number of phase boundaries are formed between the martensite and the austenitic matrix, becoming preferential corrosion channels, significantly reducing the pipe's resistance to localized corrosion and its service life. Third, in high-pressure hydrogen energy transportation scenarios, the martensitic phase boundaries provide nucleation sites for hydrogen atom enrichment and complex cracking, greatly increasing hydrogen embrittlement sensitivity. Fourth, the martensitic transformation is accompanied by a volume expansion of about 2%-4%, resulting in a decrease in the dimensional accuracy of the pipe after cold working.

[0003] To suppress the stress-induced martensitic transformation mentioned above, existing technologies mainly adopt the following approaches: First, adding molybdenum to improve austenite stability and corrosion resistance. However, molybdenum is a strategic precious metal, leading to a significant increase in raw material costs. Second, significantly increasing the nickel content to avoid martensitic transformation by adding austenite stabilizing elements. However, nickel is expensive, and excessively high nickel content weakens the material's work hardening ability. Third, using solution treatment combined with slow cooling to stabilize the austenite structure by controlling the cooling rate. However, this process has a long production cycle, high energy consumption, and still cannot avoid martensitic transformation for large deformation cold working.

[0004] In summary, existing technologies struggle to achieve a balance between low cost, non-magnetic properties, high corrosion resistance, and dimensional stability during cold working. Therefore, developing a low-cost austenitic stainless steel tube that maintains a single austenitic structure and is non-magnetic during cold working and service, without adding molybdenum and controlling nickel content, is a pressing technical problem in this field. Summary of the Invention

[0005] The purpose of this disclosure is to provide an austenitic stainless steel to address the shortcomings of the related art.

[0006] According to a first aspect of the present disclosure, an austenitic stainless steel is provided, wherein the austenitic stainless steel comprises the following components, calculated by mass%.

[0007] C: ≤0.03%, Si: ≤0.75%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities.

[0008] Among them, a, b, c, d, and e satisfy the following conditions:

[0009] 0.25≤a≤1.75;15≤b≤20;10≤c≤15;0.05≤d≤0.2;0.25≤e≤1.75;

[0010] In one aspect of this disclosure, preferably, the austenitic stainless steel comprises the following components, calculated as a percentage by mass:

[0011] C: 0.01%-0.025%, Si: f%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities.

[0012] Among them, a, b, c, d, e, and f satisfy the following conditions:

[0013] 0.50≤a≤1.50;16.5≤b≤18.0;11.5≤c≤13.5;0.08≤d≤0.18;0.50≤e≤1.50;0.25≤f≤0.65;

[0014] In one aspect of this disclosure, and more preferably, the austenitic stainless steel comprises the following components, calculated by mass percent:

[0015] C: 0.01%-0.025%, Si: f%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities.

[0016] Among them, a, b, c, d, and e satisfy the following conditions:

[0017] 0.80≤a≤1.20;17.0≤b≤17.8;12.5≤c≤13.2;0.10≤d≤0.16;0.70≤e≤1.20;0.30≤f≤0.60;

[0018] In one aspect of the embodiments of this disclosure, a, b, c, d, and f satisfy the following relation I-1:

[0019] Equation I-1: 0.5≤(c+0.5a+30d) / (b+1.5f)≤1.5.

[0020] In one aspect of the embodiments of this disclosure, preferably, a, b, c, d, and f satisfy the following relation I-2:

[0021] Equation I-2: 0.75≤(c+0.5a+30d) / (b+1.5f)≤1.15.

[0022] In one aspect of the embodiments of this disclosure, more preferably, a, b, c, d, and f satisfy the following relationship I-3:

[0023] Equation I-3: 0.90≤(c+0.5a+30d) / (b+1.5f)≤1.0.

[0024] In one aspect of the embodiments of this disclosure, a, b, c, d, and e satisfy the following relation II-1:

[0025] Equation II-1: 0.5≤(c+0.8e+30d) / (b+0.5a)≤1.5.

[0026] In one aspect of the embodiments of this disclosure, preferably, a, b, c, d, and e satisfy the following relation II-2:

[0027] Equation II-2: 0.80≤(c+0.8e+30d) / (b+0.5a)≤1.25.

[0028] In one aspect of the embodiments of this disclosure, more preferably, a, b, c, d, and e satisfy the following relation II-3:

[0029] Equation II-3: 0.95≤(c+0.8e+30d) / (b+0.5a)≤1.05.

[0030] In one aspect of the embodiments of this disclosure, a, b, c, d, and e also satisfy the following relation III-1:

[0031] Formula III-1: 0.75≤(c+0.6e+30d) / (b+a)≤1.15.

[0032] In one aspect of the embodiments of this disclosure, preferably, a, b, c, d, and e also satisfy the following relation III-2:

[0033] Formula III-2: 0.85≤(c+0.6e+30d) / (b+a)≤1.05.

[0034] In one aspect of the embodiments of this disclosure, and more preferably, a, b, c, d, and e also satisfy the following relation III-3:

[0035] Formula III-3: 0.88≤(c+0.6e+30d) / (b+a)≤0.98.

[0036] In one aspect of this disclosure, the austenitic stainless steel comprises, by weight%, the following components:

[0037] C: 0.01%-0.025%, Si: f%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities.

[0038] Among them, a, b, c, d, e, and f satisfy the following conditions:

[0039] 0.50≤a≤1.50; 16.5≤b≤18.0; 11.5≤c≤13.5; 0.08≤d≤0.18; 0.50≤e≤1.50; 0.25≤f≤0.65; and a, b, c, d, e, and f simultaneously satisfy relation I-1 and relation II-1:

[0040] Equation I-1: 0.5 ≤ (c + 0.5a + 30d) / (b + 1.5f) ≤ 1.5;

[0041] Equation II-1: 0.5≤(c+0.8e+30d) / (b+0.5a)≤1.5.

[0042] In one aspect of this disclosure, preferably, the austenitic stainless steel comprises the following components, calculated as a percentage by mass:

[0043] C: 0.01%-0.025%, Si: f%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities.

[0044] Among them, a, b, c, d, e, and f satisfy the following conditions:

[0045] 0.50≤a≤1.50; 16.5≤b≤18.0; 11.5≤c≤13.5; 0.08≤d≤0.18; 0.50≤e≤1.50; 0.25≤f≤0.65; and a, b, c, d, e, and f simultaneously satisfy relation I-2 and relation II-2:

[0046] Equation I-2: 0.75≤(c+0.5a+30d) / (b+1.5f)≤1.15;

[0047] Equation II-2: 0.80≤(c+0.8e+30d) / (b+0.5a)≤1.25.

[0048] In one aspect of this disclosure, and more preferably, the austenitic stainless steel comprises the following components, calculated by mass percent:

[0049] C: 0.01%-0.025%, Si: f%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities.

[0050] Among them, a, b, c, d, e, and f satisfy the following conditions:

[0051] 0.50≤a≤1.50; 16.5≤b≤18.0; 11.5≤c≤13.5; 0.08≤d≤0.18; 0.50≤e≤1.50; 0.25≤f≤0.65; and a, b, c, d, e, and f simultaneously satisfy relation I-2, relation II-2, and relation III-2:

[0052] Equation I-2: 0.75≤(c+0.5a+30d) / (b+1.5f)≤1.15;

[0053] Equation II-2: 0.80≤(c+0.8e+30d) / (b+0.5a)≤1.25;

[0054] Formula III-2: 0.85≤(c+0.6e+30d) / (b+a)≤1.05.

[0055] In one aspect of this disclosure, and more preferably, the austenitic stainless steel comprises the following components, calculated by mass percent:

[0056] C: 0.01%-0.025%, Si: f%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities.

[0057] Among them, a, b, c, d, e, and f satisfy the following conditions:

[0058] 0.50≤a≤1.50; 16.5≤b≤18.0; 11.5≤c≤13.5; 0.08≤d≤0.18; 0.50≤e≤1.50; 0.25≤f≤0.65; and a, b, c, d, e, and f simultaneously satisfy relation I-3, relation II-3, and relation III-3:

[0059] Equation I-3: 0.90≤(c+0.5a+30d) / (b+1.5f)≤1.0;

[0060] Equation II-3: 0.95≤(c+0.8e+30d) / (b+0.5a)≤1.05;

[0061] Formula III-3: 0.88≤(c+0.6e+30d) / (b+a)≤0.98.

[0062] In one aspect of this disclosure, the austenitic stainless steel comprises, by weight%, the following components:

[0063] C: 0.019%-0.021%, Si: 0.49%-0.51%, Mn: 0.99%-1.01%, Cr: 17.4%-17.6%, Ni: 12.9%-13.1%, N: 0.13%-0.15%, Cu: 0.89%-0.91%; the remainder is Fe and unavoidable impurities.

[0064] In one aspect of this disclosure, specifically, the austenitic stainless steel comprises, by mass%, the following components:

[0065] C: 0.020%, Si: 0.50%, Mn: 1.0%, Cr: 17.5%, Ni: 13.0%, N: 0.14%, Cu: 0.90%; the remainder is Fe and unavoidable impurities.

[0066] According to a second aspect of the present disclosure, a non-magnetic austenitic stainless steel tube is provided, which is prepared by the following steps:

[0067] Step 1: The raw material is vacuum melted and cast to obtain a round billet; then the round billet is hot-worked to obtain a tube blank; the composition of the tube blank is selected from the aforementioned austenitic stainless steel composition;

[0068] Step 2: The tube blank is subjected to solution treatment; the solution-treated product is then cold-worked to obtain the non-magnetic austenitic stainless steel tube.

[0069] In one aspect of the embodiments of this disclosure, the vacuum melting step employs vacuum induction melting (VIM) or argon-oxygen decarburization (AOD) refining.

[0070] In one aspect of the present disclosure, in step 1, the hot working is to heat the round billet to 1150℃-1200℃ and hold it at that temperature for 2-4 hours, and then hot forge or hot roll it into a tube blank, with a final forging temperature ≥950℃.

[0071] In one aspect of the embodiments of this disclosure, the solution treatment includes: heating the tube blank to 1050℃-1080℃ for solution treatment, holding for 1-2 min / mm based on the wall thickness, followed by water cooling or rapid air cooling.

[0072] In one aspect of the embodiments of this disclosure, the cold working is cold rolling or cold drawing, with a single-pass deformation of 20%-50% and a total deformation of up to 70%; due to the high stability of the alloy, intermediate annealing is not required during the cold working process.

[0073] In one aspect of this disclosure, the prepared non-magnetic austenitic stainless steel pipe can be further subjected to solution treatment and pickling passivation. The solution treatment involves heating the cold-worked pipe to 1050°C-1080°C and holding it at that temperature, followed by water cooling. The pickling passivation involves pickling the pipe with a mixture of nitric acid and hydrofluoric acid to remove surface oxide scale, followed by passivation treatment.

[0074] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0075] As can be seen from the above embodiments, this disclosure has prepared an austenitic stainless steel that can simultaneously meet the requirements of non-magnetic properties and good mechanical properties.

[0076] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Detailed Implementation

[0077] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0078] For the sake of brevity, this article only discloses a few specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0079] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0080] In this description, unless otherwise stated, "above" and "below" include the stated number.

[0081] Unless otherwise stated, the terms used in this disclosure have their common meanings as commonly understood by those skilled in the art. Unless otherwise stated, the values ​​of the parameters mentioned in this disclosure can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this disclosure).

[0082] The term "about" is used to describe and indicate small variations. When used in conjunction with an event or situation, the term may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format herein. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only numerical values ​​explicitly specified as range limits but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0083] The list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another instance, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

[0084] In this disclosure, Equation I-2 is 0.75≤(c+0.5a+30d) / (b+1.5f)≤1.15, or it can be written as 0.75≤(Ni+0.5Mn+30N) / (Cr+1.5Si)≤1.15; where Ni, Mn, and N are austenite stabilizing elements (expanding the γ phase region), and Cr and Si are ferrite / martensite promoting elements (shrinking the γ phase region). This ratio directly determines the chemical free energy difference (ΔG^{γ→α'}) of the austenite phase. When the ratio is below 0.75 (e.g., for 304 stainless steel, the ratio is about 0.54), the austenite is relatively metastable, and the mechanical driving force provided by cold working easily overcomes the phase transformation energy barrier, inducing ferromagnetic α′ martensite; when the ratio is controlled between 0.75 and 1.15, the free energy of the austenite phase is significantly reduced, making Md30 The temperature is suppressed to below -50°C, and even when plastic deformation occurs near the liquid nitrogen temperature (-196°C), the phase transformation driving force is still insufficient to trigger martensite nucleation. Furthermore, the ratio range of Equation I-2 ensures that the deformation mechanism changes from phase transformation-induced plasticity (TRIP effect) to pure dislocation slip. Dislocation slip does not change the crystal structure; after cold drawing, the material still maintains a single austenitic face-centered cubic (FCC) structure, thus the relative permeability can be stably controlled within 1.01.

[0085] In this disclosure, Equation II-2 is 0.80≤(c+0.8e+30d) / (b+0.5a)≤1.25, or it can be written as 0.80≤(Ni+0.8Cu+30N) / (Cr+0.5Mn)≤1.25. To further reduce costs, this disclosure uses Cu and N as substitutes for Ni. However, the austenite stabilization efficiency of Cu and N differs from that of Ni (N's efficiency is approximately 30 times that of Ni, while Cu's is approximately 0.8 times that of Ni). This relationship quantifies the substitution efficiency of Cu+N for Ni using weighted coefficients. Furthermore, although Mn can stabilize austenite, excessive amounts can reduce pitting corrosion resistance. Equation II-2 includes Mn in the denominator, constraining the negative contribution of Mn and ensuring that corrosion resistance does not deteriorate due to excessive reliance on Mn substitution, thus guaranteeing service life in weakly acidic and marine environments.

[0086] In this disclosure, Equation III-2 is 0.85≤(c+0.6e+30d) / (b+a)≤1.05; satisfying Equation III-2 ensures that during cold working (single-pass deformation of 20-50%, total deformation of 70%), work hardening originates from dislocation entanglement rather than phase transformation shear. Dislocation entanglement can be recovered through final solid solution, while the volume expansion (approximately 2%-4%) caused by martensitic phase transformation is irreversible.

[0087] In this disclosure, the vacuum melting step employs vacuum induction melting (VIM); the hot working involves heating the round billet to 1175°C and holding it at that temperature for 3.5 hours, followed by hot forging or hot rolling to form a tube blank, with a final forging temperature of approximately 980°C. The solution treatment includes heating the tube blank to 1060°C for solution treatment, holding it at that temperature for 2 minutes per mm of wall thickness, followed by water cooling; the cold working is cold drawing.

[0088] The present disclosure will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present disclosure are obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process is carried out at room temperature.

[0089] Example

[0090] Using scrap stainless steel, low-phosphorus scrap carbon steel, high-carbon ferrochrome (Fe-Cr65C8), nickel plate, electrolytic manganese, ferrosilicon (Fe-Si75), electrolytic copper, and ferrochrome nitride as raw materials, and by adjusting the proportions of the raw materials, a series of austenitic stainless steel pipes of Examples 1 to 7, as well as pipes of Comparative Examples 1 and 2, were prepared through vacuum induction melting (VIM), casting of round billets, hot forging / hot rolling of tube blanks, solution treatment, and cold drawing (cold rolling) processes (specific steps as described above).

[0091] The elemental contents of Examples 1 to 7 and Comparative Examples 1-2 are shown in Table 1 below:

[0092] Table 1

[0093] Example 1 0.02 0.50 1.00 17.50 13.00 0.14 0.90 Example 2 0.02 0.25 1.48 17.98 11.52 0.08 0.52 Example 3 0.02 0.65 0.50 16.50 13.50 0.18 1.50 Example 4 0.02 0.65 0.50 18.00 11.50 0.08 0.50 Example 5 0.02 0.25 1.50 16.50 13.50 0.18 1.50 Example 6 0.02 0.50 0.80 17.80 12.00 0.16 0.80 Example 7 0.02 0.40 1.20 17.00 12.80 0.12 1.20 Comparative Example 1 0.05 0.60 1.80 18.20 8.10 0.04 0.30 Comparative Example 2 0.02 0.45 1.20 16.80 10.20 0.06 0.40

[0094] Performance testing:

[0095] Metallographic structure testing: Metallographic samples were prepared according to ASTM E3 sample preparation specifications. After etching, the microstructure was observed under a metallographic microscope to determine the presence of α′ martensite. In addition, phase analysis was performed using the diffraction effect of X-rays in crystalline materials in accordance with GB / T 13305-2024 to quantitatively determine the martensite content in austenitic stainless steel.

[0096] Relative permeability test: The permeability of each embodiment and comparative example was tested using a permeability meter.

[0097] Mechanical properties (yield strength Rp0.2, tensile strength Rm) were tested: obtained by room temperature tensile test in accordance with GB / T 228.1-2021.

[0098] Corrosion resistance: Intergranular corrosion test was conducted in accordance with GB / T 4334-2020; the specific performance tests are shown in Table 2.

[0099] Table 2

[0100] Example 1 Single austenite 1.003 265 580 qualified Example 2 Single austenite (microtwins) 1.008 245 555 Unqualified Example 3 Single austenite (coarse slip band) 1.006 235 540 qualified Example 4 Austenite + 15% α′ martensite 1.25 285 610 qualified Example 5 Single austenite (coarse grains) 1.008 230 535 Unqualified Example 6 Single austenite 1.005 258 572 qualified Example 7 Single austenite 1.004 260 575 qualified Comparative Example 1 Austenite + 35% α′ martensite 1.45 320 680 Unqualified Comparative Example 2 Austenite + 20% α′ martensite 1.32 295 635 Unqualified

[0101] Among them, Examples 1, 6, and 7 simultaneously satisfy Relations I-2, II-2, and III-2; Example 2 only satisfies Relation I-2, but not Relations II-2 and III-2 (both are too low); Example 3 satisfies Relations I-2 and II-2 but not Relation III-2 (too high); Example 4 does not satisfy Relation I-2 (too low); Example 5 does not satisfy Relations I-2 and III-2 (both are too high). It can be seen that Example 4 undergoes a stress-induced martensitic phase transformation after cold drawing, resulting in a significant increase in relative permeability, failing to meet the non-magnetic requirement. Although Example 2 satisfies Relation I-2, it does not satisfy Relation II-2, meaning that the substitution efficiency of Cu+N for Ni is unbalanced, leading to unqualified intergranular corrosion. Although Example 3 is qualified in terms of non-magnetism and corrosion resistance, Formula III-2 exceeds the upper limit, indicating that the stacking fault energy (SFE) is too high. During cold drawing, the deformation mechanism changes from uniform dislocation slip to non-uniform shear of coarse slip bands, resulting in a significant decrease in both yield strength and tensile strength. In Example 5, Formula I-2 exceeds the upper limit, indicating that the austenite is too stable. Although no martensite is generated after cold drawing, the excessive austenite stability leads to insufficient work hardening ability, and both yield strength and tensile strength are significantly lower than those in Example 1.

[0102] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. An austenitic stainless steel, characterized in that, The austenitic stainless steel comprises the following components, calculated as a percentage by mass: C: ≤0.03%, Si: ≤0.75%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities. Among them, a, b, c, d, and e satisfy the following conditions: 0.25≤a≤1.75;15≤b≤20;10≤c≤15;0.05≤d≤0.2;0.25≤e≤1.75; 2. The austenitic stainless steel according to claim 1, characterized in that, The austenitic stainless steel comprises the following components, calculated as a percentage by mass: C: 0.01%-0.025%, Si: f%, Mn: a%, Cr: b%, Ni: c%, N: d%, Cu: e%; the remainder is Fe and unavoidable impurities. Among them, a, b, c, d, e, and f satisfy the following conditions: 0.50≤a≤1.50;16.5≤b≤18.0;11.5≤c≤13.5;0.08≤d≤0.18;0.50≤e≤1.50;0.25≤f≤0.65; 3. The austenitic stainless steel according to claim 2, characterized in that, a, b, c, d, and f satisfy the following relation I-1: Equation I-1: 0.5≤(c+0.5a+30d) / (b+1.5f)≤1.

5.

4. The austenitic stainless steel according to claim 3, characterized in that, a, b, c, d, and f satisfy the following relation I-2: Equation I-2: 0.75≤(c+0.5a+30d) / (b+1.5f)≤1.

15.

5. The austenitic stainless steel according to claim 3, characterized in that, a, b, c, d, and e satisfy the following relation II-1: Equation II-1: 0.5≤(c+0.8e+30d) / (b+0.5a)≤1.

5.

6. The austenitic stainless steel according to claim 5, characterized in that, a, b, c, d, and e satisfy the following relation II-2: Equation II-2: 0.80≤(c+0.8e+30d) / (b+0.5a)≤1.

25.

7. The austenitic stainless steel according to claim 3, characterized in that, a, b, c, d, and e satisfy the following relation III-1: Formula III-1: 0.75≤(c+0.6e+30d) / (b+a)≤1.

15.

8. The austenitic stainless steel according to claim 7, characterized in that, a, b, c, d, and e satisfy the following relation III-2: Formula III-2: 0.85≤(c+0.6e+30d) / (b+a)≤1.

05.

9. The austenitic stainless steel according to any one of claims 1-8, characterized in that, The austenitic stainless steel comprises the following components, calculated as a percentage by mass: C: 0.019%-0.021%, Si: 0.49%-0.51%, Mn: 0.99%-1.01%, Cr: 17.4%-17.6%, Ni: 12.9%-13.1%, N: 0.13%-0.15%, Cu: 0.89%-0.91%; the remainder is Fe and unavoidable impurities.

10. A non-magnetic austenitic stainless steel pipe, characterized in that, The non-magnetic austenitic stainless steel tube is prepared through the following steps: Step 1: The raw materials are melted and cast to obtain a round billet; then the round billet is hot-worked to obtain a tube blank; the composition of the tube blank is selected from the composition of the austenitic stainless steel according to any one of claims 1-9; Step 2: The tube blank is subjected to solution treatment; the solution-treated product is then cold-worked to obtain the non-magnetic austenitic stainless steel tube.