Austenitic stainless steel and corrosion-resistant components

Abstract

To provide an inexpensive austenitic stainless steel which has corrosion resistance equivalent to SUS316L and is excellent in workability and manufacturability.SOLUTION: There is provided an austenitic stainless steel which comprises, by mass, 0.010 to 0.100% of C, 2.0% or less of Si, 3.0% or less of Mn, 0.035% or less of P, 0.030% or less of S, 6.0 to 14.0% of Ni, 16.0% or more and less than 20.0% of Cr, 3.0% or less of Mo, 0.05 to 3.0% of Cu, 0.20% or less of Al, 0.100 to 0.250% of N and the balance comprising Fe and inevitable impurities, wherein A value represented by the following expression (1) is -2 to 5.5. A=3(Cr+Mo)+4.5Si-2.8Ni-1.4(Mn+Cu)-84(C+N)-19.8 (1) [Cr, Mo, Si, Ni, Mn, Cu, C and N represent the content (mass%) of each element.]SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an austenitic stainless steel and a corrosion-resistant member. [Background technology]

[0002] SUS316L, a type of austenitic stainless steel, has good corrosion resistance in corrosive environments such as seawater and saltwater, and is also easy to process and manufacture, making it suitable for a variety of applications, including household goods, building materials, and automotive parts. However, SUS316L has the drawback of increasing product prices due to the inclusion of expensive elements such as Ni and Mo. Therefore, there is a demand for inexpensive austenitic stainless steels that have the same level of corrosion resistance as SUS316L, but are also excellent in workability and manufacturability.

[0003] Patent Document 1 proposes an austenitic stainless steel having three layers on its surface, in order from the surface to the inner layer: an outermost layer containing nitrides of Fe and Cr in a γ phase; a layer made of an S phase in which N is supersaturated in solid solution at 10% by mass or more; and a carbon-enriched layer, as an austenitic stainless steel that has improved corrosion resistance while minimizing the use of expensive elements such as Mo. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-188417 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the austenitic stainless steel described in Patent Document 1 requires complex surface treatment to form a predetermined layer on the surface, which results in low manufacturing efficiency and extra costs due to the surface treatment.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide an inexpensive austenitic stainless steel that has corrosion resistance at a level equivalent to that of SUS316L and is excellent in workability and manufacturability, and a corrosion-resistant member made of this austenitic stainless steel. [Means for solving the problem]

[0007] The present inventors conducted extensive research into the composition of austenitic stainless steels based on the composition of SUS316L. To improve the manufacturability of austenitic stainless steels, it is desirable to increase the content of the δ-ferrite phase (hereinafter referred to as the "δ-phase"), which has a high solid solubility of P and S in the solidified state. However, as the δ-phase content increases, cracking becomes more likely due to the difference in strength between the δ-phase and the austenite phase (hereinafter referred to as the "γ-phase"). Therefore, the δ-phase content must be controlled within an appropriate range. However, reducing the content of expensive Ni increases the δ-phase content. Therefore, to ensure a balance between the δ-phase and the γ-phase, it is necessary to add γ-forming elements (e.g., Mn, Cu, N). However, increasing the content of Mn or Cu reduces corrosion resistance, and increasing the content of N increases hardness and reduces workability. In light of these issues, the present inventors optimized the composition of austenitic stainless steels and discovered that a specific composition can solve the above problems, leading to the completion of the present invention.

[0008] That is, the present invention provides a steel sheet containing, on a mass basis, C: 0.010 to 0.100%, Si: 2.0% or less, Mn: 3.0% or less, P: 0.035% or less, S: 0.030% or less, Ni: 6.0 to 14.0%, Cr: 16.0% or more and less than 20.0%, Mo: less than 0.01%, Cu: 0.05 to 3.0%, Al: more than 0% and 0.20% or less, and N: 0.100 to 0.250%. 、B:0.001~0.004% The austenitic stainless steel contains the above-mentioned elements, with the balance being Fe and impurities, and has an A value, represented by the following formula (1), of -2 to 5.5. A=3(Cr+Mo)+4.5Si-2.8Ni-1.4(Mn+Cu)-84(C+N)-19.8 (1) In the formula, Cr, Mo, Si, Ni, Mn, Cu, C, and N represent the content (mass%) of each element.

[0009] The present invention also provides a corrosion-resistant member containing the above-mentioned austenitic stainless steel. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an inexpensive austenitic stainless steel that has corrosion resistance at the same level as SUS316L and is excellent in workability and manufacturability, as well as a corrosion-resistant member made of this austenitic stainless steel. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following is a detailed description of the embodiments of the present invention. The present invention is not limited to the following embodiments, and it should be understood that modifications and improvements made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention are also within the scope of the present invention. In this specification, the "%" designation for components means "% by mass" unless otherwise specified.

[0012] An austenitic stainless steel according to an embodiment of the present invention contains C: 0.010 to 0.100%, Si: 2.0% or less, Mn: 3.0% or less, P: 0.035% or less, S: 0.030% or less, Ni: 6.0 to 14.0%, Cr: 16.0% or more but less than 20.0%, Mo: 3.0% or less, Cu: 0.05 to 3.0%, Al: 0.20% or less, N: 0.100 to 0.250%, and the balance being Fe and impurities. In this specification, the term "impurities" refers to components that are mixed in during the industrial production of austenitic stainless steel due to various factors in raw materials such as ores and scraps, and in the manufacturing process, and are acceptable within a range that does not adversely affect the present invention.

[0013] Moreover, the austenitic stainless steel according to the embodiment of the present invention may further contain B: 0.001 to 0.004%. In addition, the austenitic stainless steel according to an embodiment of the present invention may further contain one or more selected from Ca: 0.0001% to 0.10%, Mg: 0.0001% to 0.10%, and REM: 0.0001% to 0.10%. Furthermore, the austenitic stainless steel according to an embodiment of the present invention may further contain one or more selected from Ti: 0.001% to 1.0%, Nb: 0.001% to 1.0%, V: 0.001% to 1.0%, Zr: 0.001% to 1.0%, W: 0.001 to 1.0%, Co: 0.001 to 1.0%, Hf: 0.001 to 1.0%, Ta: 0.001 to 1.0%, and Sn: 0.001 to 0.10%. Hereinafter, each component will be described in detail.

[0014] <C: 0.010 to 0.100%> If the C content is too high, the corrosion resistance of the austenitic stainless steel will decrease. Therefore, the upper limit value of the C content is controlled to 0.100%, preferably 0.095%, more preferably 0.090%. On the other hand, if the C content is too low, it will lead to an increase in refining cost. Therefore, the lower limit value of the C content is controlled to 0.010%, preferably 0.015%, more preferably 0.020%. In this specification, "corrosion resistance" means the corrosion resistance in a corrosion environment containing NaCl such as seawater or salt water.

[0015] <Si: 2.0% or less> If the Si content is too high, the workability of the austenitic stainless steel will decrease. Therefore, the upper limit value of the Si content is controlled to 2.0%, preferably 1.98%, more preferably 1.95%. On the other hand, the lower limit value of the Si content is not particularly limited, but preferably 0.01%, more preferably 0.05%, still more preferably 0.1%.

[0016] <Mn: 3.0% or less> Mn is an austenite phase (γ-phase) forming element. If the Mn content is too high, the corrosion resistance of austenitic stainless steel will decrease. Therefore, the upper limit of the Mn content is controlled to 3.0%, preferably 2.5%, more preferably 2.0%. On the other hand, the lower limit of the Mn content is not particularly limited, but is preferably 0.01%, more preferably 0.05%, and still more preferably 0.1%.

[0017] <P: 0.035% or less> If the P content is too high, the workability of austenitic stainless steel will decrease. Therefore, the upper limit of the P content is controlled to 0.035%, preferably 0.034%, more preferably 0.033%. On the other hand, the lower limit of the P content is not particularly limited, but is preferably 0.001%, more preferably 0.005%, and still more preferably 0.010%.

[0018] <S: 0.030% or less> If the S content is too high, the manufacturability of austenitic stainless steel will decrease. Therefore, the upper limit of the S content is controlled to 0.030%, preferably 0.025%, more preferably 0.020%. On the other hand, the lower limit of the S content is not particularly limited, but is preferably 0.0001%, more preferably 0.0003%, and still more preferably 0.0005%.

[0019] <Ni: 6.0 - 14.0%> Ni is an austenite phase (γ-phase) forming element like Mn. Since Ni is expensive, if the content is too high, it will lead to an increase in manufacturing cost. Therefore, the upper limit of the Ni content is controlled to 14.0%, preferably 13.8%, more preferably 13.5%. On the other hand, if the Ni content is too low, the workability of austenitic stainless steel will decrease. Therefore, the lower limit of the Ni content is controlled to 6.0%, preferably 6.05%.

[0020] <Cr: 16.0% or more and less than 20.0%> If the Cr content is too high, the formation of intermetallic compounds (σ phase) is promoted, resulting in a decrease in the workability of austenitic stainless steel. Therefore, the Cr content is controlled to be less than 20.0%, preferably 19.8% or less. On the other hand, if the Cr content is too low, sufficient corrosion resistance cannot be obtained. Therefore, the lower limit value of the Cr content is controlled to be 16.0%, preferably 16.2%.

[0021] <Mo: 3.0% or less> Since Mo is expensive, if the Mo content is too high, it will lead to an increase in manufacturing costs. Therefore, the upper limit value of the Mo content is controlled to be 3.0%, preferably 2.0%, more preferably 1.0%. On the other hand, the lower limit value of the Mo content is not particularly limited, but preferably 0.001%, more preferably 0.002%, and even more preferably 0.003%.

[0022] <Cu: 0.05 - 3.0%> If the Cu content is too high, the corrosion resistance of austenitic stainless steel will decrease. Therefore, the upper limit value of the Cu content is controlled to be 3.0%, preferably 2.0%, more preferably 1.0%. On the other hand, if the Cu content is too low, the workability of austenitic stainless steel will decrease. Therefore, the lower limit of the Cu content is controlled to be 0.05%, preferably 0.10%, more preferably 0.15%.

[0023] <Al: 0.20% or less> If the Al content is too high, the amount of inclusions generated will increase and the quality will deteriorate. Therefore, the upper limit value of the Al content is controlled to be 0.20%, preferably 0.10%, more preferably 0.05%. On the other hand, the lower limit of the Al content is not particularly limited, but preferably 0.0001%, more preferably 0.0002%, and even more preferably 0.0003%.

[0024] <N: 0.100 - 0.250%> If the N content is too high, the workability of the austenitic stainless steel will decrease. Therefore, the upper limit of the N content is controlled to 0.250%, preferably 0.230%, and more preferably 0.220%. On the other hand, if the N content is too low, the austenitic stainless steel will not have sufficient corrosion resistance. Therefore, the lower limit of the N content is controlled to 0.100%, and preferably 0.110%.

[0025] <B:0.001~0.004%> If the B content is too high, the corrosion resistance of the austenitic stainless steel will decrease. Therefore, the upper limit of the B content is controlled to 0.004%, preferably 0.003%. On the other hand, if the B content is too low, the manufacturability of the austenitic stainless steel will decrease. Therefore, the lower limit of the B content is controlled to 0.001%, preferably 0.002%.

[0026] <Ca:0.0001%~0.10%> Ca is an element added as needed to improve hot workability. From the viewpoint of obtaining the effects of Ca, the lower limit of the Ca content is controlled to 0.0001%, preferably 0.0005%, and more preferably 0.001%. On the other hand, if the Ca content is too high, the amount of inclusions generated increases, degrading the quality. Therefore, the upper limit of the Ca content is controlled to 0.10%, preferably 0.05%, and more preferably 0.01%.

[0027] <Mg:0.0001%~0.10%> Mg is an element added as needed to improve hot workability. From the viewpoint of obtaining the effects of Mg, the lower limit of the Mg content is controlled to 0.0001%, preferably 0.0005%, and more preferably 0.001%. On the other hand, if the Mg content is too high, the amount of inclusions generated increases, degrading the quality. Therefore, the upper limit of the Mg content is controlled to 0.10%, preferably 0.05%, and more preferably 0.01%.

[0028] <REM:0.0001%~0.10%> REM is an element added as needed to improve hot workability. From the viewpoint of obtaining the effects of REM, the lower limit of the REM content is controlled to 0.0001%, preferably 0.0005%, and more preferably 0.001%. Furthermore, since REM is expensive, if the REM content is too high, the manufacturing cost will increase. Therefore, the upper limit of the REM content is controlled to 0.10%, preferably 0.05%, and more preferably 0.01%.

[0029] <Ti:0.001%~1.0%> Ti is an element that is added as needed to fix C in steel and improve intergranular corrosion resistance. From the viewpoint of obtaining the effects of Ti, the lower limit of the Ti content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the Ti content is too high, the workability of the austenitic stainless steel will decrease. Therefore, the upper limit of the Ti content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0030] <Nb:0.001%~1.0%> Nb is an element that is added as needed to fix C in steel and improve intergranular corrosion resistance. From the viewpoint of obtaining the effects of Nb, the lower limit of the Nb content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the Nb content is too high, the workability of austenitic stainless steel will decrease. Therefore, the upper limit of the Nb content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0031] <V:0.001%~1.0%> V is an element that is added as needed to fix C in steel and improve intergranular corrosion resistance. From the viewpoint of obtaining the effects of V, the lower limit of the V content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the V content is too high, the workability of the austenitic stainless steel will decrease. Therefore, the upper limit of the V content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0032] <Zr:0.001%~1.0%> Zr is an element that is added as needed to fix C in steel and improve intergranular corrosion resistance. From the viewpoint of obtaining the effects of Zr, the lower limit of the Zr content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the Zr content is too high, the workability of the austenitic stainless steel will decrease. Therefore, the upper limit of the Zr content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0033] <W:0.001~1.0%> W is an element that is added as needed to improve high-temperature strength and corrosion resistance. From the viewpoint of obtaining the effects of W, the lower limit of the W content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the W content is too high, the workability of the austenitic stainless steel decreases and the manufacturing cost increases. Therefore, the upper limit of the W content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0034] <Co:0.001~1.0%> Co is an element that is added as needed to improve corrosion resistance. From the viewpoint of obtaining the effects of Co, the lower limit of the Co content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. On the other hand, if the Co content is too high, the workability of the austenitic stainless steel decreases and the manufacturing cost increases. Therefore, the upper limit of the Co content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0035] <Hf:0.001~1.0%> Hf is an element added as needed to fix C in steel and improve intergranular corrosion resistance. From the viewpoint of obtaining the effects of Hf, the lower limit of the Hf content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the Hf content is too high, the workability of austenitic stainless steel will decrease. Therefore, the upper limit of the Hf content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0036] <Ta:0.001~1.0%> Ta is an element that is added as needed to fix C in steel and improve intergranular corrosion resistance. From the viewpoint of obtaining the effects of Ta, the lower limit of the Ta content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the Ta content is too high, the workability of the austenitic stainless steel will decrease. Therefore, the upper limit of the Ta content is controlled to 1.0%, preferably 0.8%, and more preferably 0.5%.

[0037] <Sn:0.001~0.10%> Sn is an element that is added as needed to improve corrosion resistance. From the viewpoint of obtaining the effects of Sn, the lower limit of the Sn content is controlled to 0.001%, preferably 0.005%, and more preferably 0.010%. Furthermore, if the Sn content is too high, the manufacturability of austenitic stainless steel decreases. Therefore, the upper limit of the Sn content is controlled to 0.10%, preferably 0.05%, and more preferably 0.01%.

[0038] In the austenitic stainless steel according to the embodiment of the present invention, the A value represented by the following formula (1) is from −2 to 5.5, preferably from −1.8 to 5.3, and more preferably from −1.7 to 5.0. A=3(Cr+Mo)+4.5Si-2.8Ni-1.4(Mn+Cu)-84(C+N)-19.8 (1) In the formula, Cr, Mo, Si, Ni, Mn, Cu, C, and N represent the content (mass%) of each element. By controlling the A-value within the above range, it is possible to achieve both manufacturability and workability of austenitic stainless steel. In particular, by setting the A-value to -2 or more, oxidation of the grain boundaries can be suppressed, making it difficult for oxide scale to remain. Furthermore, by setting the A-value to 5.5 or less, edge breakage during the production of austenitic stainless steel can be suppressed, and elongation that allows the austenitic stainless steel to be processed into various shapes can be ensured during processing.

[0039] The austenitic stainless steel according to the embodiment of the present invention may be in any shape as long as it has the above-described characteristics. For example, the austenitic stainless steel may be in the form of various plate materials such as a hot-rolled plate, a hot-rolled annealed plate, a cold-rolled plate, or a cold-rolled annealed plate, but is preferably a cold-rolled annealed plate from the viewpoint of manufacturability.

[0040] The austenitic stainless steel according to the embodiment of the present invention can be produced by using a method known in the art, except for producing a stainless steel having the above-described composition. Specifically, when the austenitic stainless steel is a cold-rolled annealed sheet, it can be produced as follows. First, a stainless steel having the above-described composition is produced by melting and forging or casting, and then hot-rolling to obtain a hot-rolled sheet. Next, the hot-rolled sheet is appropriately annealed, pickled, and cold-rolled to obtain a cold-rolled sheet. Next, the cold-rolled sheet is appropriately annealed and pickled to obtain a cold-rolled annealed sheet. The conditions for each step are not particularly limited and may be adjusted appropriately depending on the composition of the stainless steel.

[0041] The austenitic stainless steel according to the embodiment of the present invention, which has the above-mentioned characteristics, has good manufacturability and workability, and its corrosion resistance in corrosive environments containing NaCl, such as seawater or saltwater, is at the same level as SUS316L, so it can be used as a material for corrosion-resistant components used in such corrosive environments. Furthermore, this austenitic stainless steel can reduce manufacturing costs by reducing the content of expensive elements such as Mo and Ni, making it suitable for application to various components that use SUS316L. [Example]

[0042] The present invention will be described in detail below with reference to examples, but the present invention should not be construed as being limited to these examples. 、3、 4 and 5 is a reference example.

[0043] 30 kg of stainless steel having the composition shown in Table 1 was vacuum melted and forged into a 30 mm thick plate, which was then heated at 1230°C for 2 hours and hot rolled to a 4 mm thick plate to obtain a hot-rolled plate. The hot-rolled plate was then annealed and pickled to obtain a hot-rolled annealed plate, which was then cold-rolled to obtain a cold-rolled plate. The cold-rolled plate was then annealed, water-cooled, and pickled to obtain a cold-rolled annealed plate (austenitic stainless steel). Note that Comparative Example 8 is a steel type equivalent to SUS316L, which contains large amounts of expensive Ni and Mo.

[0044] [Table 1]

[0045] The cold-rolled and annealed sheets obtained above, as well as the hot-rolled and hot-rolled and annealed sheets which are intermediate materials thereof, were subjected to the following evaluations.

[0046] <Manufacturability> The manufacturability was evaluated by measuring the maximum edge cut length of the hot-rolled sheet and observing the oxide scale on the surface of the hot-rolled and annealed sheet. The maximum edge cut length of the hot-rolled sheet was determined by measuring the edge cut length of the hot-rolled sheet and taking the maximum value as the maximum edge cut length. The surface of the hot-rolled and annealed sheet was scraped off by 20 μm in the thickness direction, and the presence or absence of black oxide scale on the surface was evaluated. In the evaluation of manufacturability, products in which the maximum edge cut length was 3 mm or less and no oxide scale was observed were rated as pass (◯), and products in which the maximum edge cut length exceeded 3 mm and / or oxide scale was observed were rated as fail (×).

[0047] <Workability> The workability was evaluated using cold-rolled and annealed sheets obtained by cold-rolling to a thickness of 0.3 mm, followed by annealing, water cooling, and pickling. The workability was evaluated in accordance with the tensile test method specified in JIS Z2241:2011. Specifically, No. 13B test pieces were cut from the center of the width direction of the cold-rolled and annealed sheets, and a tensile test was performed at a tension speed of 20 mm / min to measure the elongation (%). In this evaluation, a specimen that achieved 50% elongation, which allows it to be processed into various shapes, was evaluated as passing (◯), and a specimen that achieved less than 50% elongation was evaluated as failing (×).

[0048] <Corrosion resistance> Corrosion resistance was evaluated using cold-rolled and annealed sheets obtained by cold-rolling to a thickness of 1.0 mm, followed by annealing, water cooling, and pickling. Corrosion resistance was measured in accordance with JIS G0577:2014. A 15 mm × 20 mm test piece was cut from the center of the cold-rolled and annealed sheet in the width direction and then wet-polished with #600 polishing paper. Next, the electrode surface (exposed portion) of the test piece was insulated with silicone resin except for the electrode surface to obtain a test piece for pitting potential measurement. Next, the test piece for pitting potential measurement was immersed in a 3.5% NaCl solution at 30°C that had been thoroughly degassed with Ar, and potentiodynamic anodic polarization was performed at 20 mV / min from the natural potential to measure the pitting potential. The pitting potential was measured at a current of 100 μA / cm. 2 In this evaluation, a pitting potential of 0.4 V vs. Ag / AgCl (hereinafter, all potentials are based on Ag / AgCl) or higher was evaluated as pass (◯), and a potential of less than 0.4 V was evaluated as fail (×).

[0049] The results of the above evaluations are shown in Table 2.

[0050] [Table 2]

[0051] As shown in Table 2, Example 1 , 2 and 4 The austenitic stainless steels of 1 to 6 satisfied the prescribed composition and A value, and therefore were excellent in manufacturability, workability, and corrosion resistance. On the other hand, the austenitic stainless steels of Comparative Examples 1 and 2 had insufficient manufacturability because their A values ​​were outside the range. The austenitic stainless steel of Comparative Example 3 had insufficient workability because its Ni content was too low. The austenitic stainless steel of Comparative Example 4 had insufficient corrosion resistance because its Cr content was too low. The austenitic stainless steel of Comparative Example 5 had insufficient workability and manufacturability because its N content was too high and its A value was too low. The austenitic stainless steel of Comparative Example 6 had insufficient corrosion resistance and manufacturability because its Cr content was too low and its A value was too low. The austenitic stainless steel of Comparative Example 7 had insufficient corrosion resistance and manufacturability because its Si content was too high and its Cr content was too low. The austenitic stainless steel (SUS316L) of Comparative Example 8 was good in all of its manufacturability, workability, and corrosion resistance, but contained large amounts of expensive Ni and Mo, which increased its manufacturing costs.

[0052] As can be seen from the above results, the present invention can provide an inexpensive austenitic stainless steel that has corrosion resistance at a level equivalent to that of SUS316L and is excellent in workability and manufacturability, as well as a corrosion-resistant member made from this austenitic stainless steel.

Claims

1. An austenitic stainless steel containing, on a mass basis, 0.010 to 0.100% C, 2.0% or less Si, 3.0% or less Mn, 0.035% or less P, 0.030% or less S, 6.0 to 14.0% Ni, 16.0% or more and less than 20.0% Cr, less than 0.01% Mo, 0.05 to 3.0% Cu, more than 0% and less than 0.20% Al, 0.100 to 0.250% N, and 0.001 to 0.004% B, with the balance being Fe and impurities, and having an A value, expressed by the following formula (1), of -2 to 5.

5. A=3(Cr+Mo)+4.5Si-2.8Ni-1.4(Mn+Cu)-84(C+N)-19.8 (1) In the formula, Cr, Mo, Si, Ni, Mn, Cu, C, and N represent the content (mass%) of each element.

2. The austenitic stainless steel according to claim 1, further comprising, on a mass basis, 0.0001% to 0.10% Mg.

3. 3. The austenitic stainless steel according to claim 1, further comprising, on a mass basis, one or more selected from Ti: 0.001% to 1.0%, Nb: 0.001% to 1.0%, V: 0.001% to 1.0%, Zr: 0.001% to 1.0%, W: 0.001 to 1.0%, Co: 0.001 to 1.0%, Hf: 0.001 to 1.0%, Ta: 0.001 to 1.0%, and Sn: 0.001 to 0.10%.

4. A corrosion-resistant member comprising the austenitic stainless steel according to any one of claims 1 to 3.

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