Ferritic stainless steel material and method for manufacturing vibration-damping member

Abstract

To provide a ferritic stainless steel that can enhance the vibration damping by recrystallization treatment while suppressing thermal deformation.SOLUTION: Provided is a ferritic stainless steel material that contains C: 0.05 mass% or less, Mn: 1.0 mass% or less, Ni: 0.60 mass% or less, P: 0.05 mass% or less, S: 0.03 mass% or less, Cr: 10.5 to 24.0 mass%, N: 0.03 mass% or less, Cu: 0.60% by mass or less, Mo: 2.5% by mass or less, Si: 3.0 mass% or less, Al: 5.0 mass% or less and the balance consisting of Fe and unavoidable impurities. The ferritic stainless steel material has an average grain boundary distortion rate of 1% or more and less than 15%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a ferritic stainless steel material and a vibration damping member.

Background Art

[0002] With the electrification of automobiles, the noise and vibration caused by the engine have disappeared, and the quietness inside the vehicle has improved. As a result, noises that were previously masked by engine noise and high-frequency noises specific to electrification are more likely to be perceived as abnormal noises by passengers' ears, and the level of vibration damping of materials used in automobiles has increased. In addition, in electronic devices such as hard disks, vibration causes malfunctions and failures, so vibration damping is also required for materials used in electronic device components.

[0003] Resin is a typical example of a material having vibration damping properties, but it is often difficult to use from the viewpoints of strength, environmental resistance (corrosion resistance and heat resistance), heat dissipation, etc. Therefore, a metallic material having vibration damping properties is required. Metallic materials having vibration damping properties are roughly classified into composite type, ferromagnetic type, dislocation type, and twin type according to the vibration energy attenuation mechanism. Among them, ferritic stainless steel materials are ferromagnetic and have a ferromagnetic type attenuation mechanism. In the ferromagnetic type, when an external force such as vibration is applied, the magnetic domains are rearranged in one direction, and when the load is removed, the magnetic domains are rearranged randomly. The residual strain at this time absorbs the vibration energy and attenuates the vibration.

[0004] As a ferrite stainless steel material with excellent vibration damping properties, it has a chemical composition of C: 0.001 to 0.03 mass%, Si: 0.1 to 1.0 mass%, Mn: 0.1 to 2.0 mass%, Ni: 0.01 to 0.6 mass%, Cr: 10.5 to 24.0 mass%, N: 0.001 to 0.03 mass%, Nb: 0 to 0.8 mass%, Ti: 0 to 0.5 mass%, Cu: 0 to 2.0 mass%, Mo: 0 to 2.5 mass%, V: 0 to 1.0 mass%, Al: 0 to 0.3 mass%, Zr: 0 to 0.3 mass%, Co: 0 to 0.6 mass%, REM: 0 to 0.1 mass%, Ca: 0 to 0.1 mass%, with the balance being Fe and inevitable impurities. It has a matrix of single-phase ferrite, a metal structure with an average crystal grain size of ferrite crystal grains of 0.3 to 3.0 mm, and a vibration damping ferrite stainless steel material with a residual magnetic flux density of 45 mT or less has been proposed (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the ferrite stainless steel material described in Patent Document 1 has a problem that it is likely to deform because it is necessary to perform a recrystallization treatment at high temperature for a long time (final annealing at 1200°C for 120 minutes or 950°C for 120 minutes) in order to improve the vibration damping property.

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a ferrite stainless steel material capable of enhancing the vibration damping property by recrystallization treatment while suppressing thermal deformation. Another object of the present invention is to provide a vibration damping member with less thermal deformation and excellent vibration damping properties.

Means for Solving the Problems

[0008] As a result of intensive research to solve the above problems, the inventors of the present invention have found that by controlling the composition and average grain boundary strain rate of a ferritic stainless steel material within a predetermined range, it is possible to shorten the recrystallization treatment and achieve both improvement in vibration damping performance and suppression of thermal deformation, thus completing the present invention.

[0009] That is, the present invention relates to a ferritic stainless steel material containing C: 0.05% by mass or less, Mn: 1.0% by mass or less, Ni: 0.60% by mass or less, P: 0.05% by mass or less, S: 0.03% by mass or less, Cr: 10.5 to 24.0% by mass, N: 0.03% by mass or less, Cu: 0.60% by mass or less, Mo: 2.5% by mass or less, Si: 3.0% by mass or less, Al: 5.0% by mass or less, with the balance being Fe and inevitable impurities, and having an average grain boundary strain rate of 1% or more and less than 15%.

[0010] Further, the present invention relates to the above-mentioned ferritic stainless steel material including subjecting it to recrystallization treatment at 900 to 1100 °C for 5 to 30 minutes vibration damping member manufacturing method is.

Effects of the Invention

[0011] According to the present invention, it is possible to provide a ferritic stainless steel material and a vibration damping member capable of enhancing vibration damping performance by recrystallization treatment while suppressing thermal deformation.

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be specifically described. It should be understood that the present invention is not limited to the following embodiments, and modifications and improvements may be appropriately made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention, and such modified and improved embodiments also fall within the scope of the present invention.

[0013] The ferritic stainless steel material according to an embodiment of the present invention contains C: 0.05% by mass or less, Mn: 1.0% by mass or less, Ni: 0.60% by mass or less, P: 0.05% by mass or less, S: 0.03% by mass or less, Cr: 10.5 to 24.0% by mass, N: 0.03% by mass or less, Cu: 0.60% by mass or less, Mo: 2.5% by mass or less, Si: 3.0% by mass or less, Al: 5.0% by mass or less, and the balance consists of Fe and inevitable impurities. Here, in this specification, "inevitable impurities" means components such as O that are difficult to remove. Such components are inevitably mixed in at the stage of melting the raw materials. Further, the ferritic stainless steel material according to an embodiment of the present invention may further contain at least one selected from Nb: 0.50% by mass or less, Ti: 0.50% by mass or less, Zr: 1.0% by mass or less, Co: 1.0% by mass or less, V: 1.0% by mass or less, W: 1.0% by mass or less, REM: 0.10% by mass or less, Ca: 0.10% by mass or less, Sn: 0.10% by mass or less, B: 0.01% by mass or less.

[0014] C is an element that affects properties such as the intergranular corrosion resistance (sensitization suppression effect) and workability of the ferritic stainless steel material. If the content of C is too high, the workability and intergranular corrosion resistance of the ferritic stainless steel material will decrease. Therefore, the upper limit value of the content of C is controlled to 0.05% by mass, preferably 0.045% by mass, more preferably 0.04% by mass. On the other hand, the lower limit value of the content of C is not particularly limited, but reducing the content of C will lead to an increase in refining cost. Therefore, the lower limit value of the content of C is preferably 0.0005% by mass, preferably 0.001% by mass.

[0015] Mn is useful as a deoxidizing element. If the content of Mn is too high, it is easy to generate MnS that becomes a corrosion initiation point, and the ferrite phase is destabilized. Therefore, the upper limit value of the content of Mn is controlled to 1.0% by mass, preferably 0.9% by mass, more preferably 0.8% by mass. On the other hand, the lower limit value of the content of Mn is not particularly limited, but is preferably 0.01% by mass, more preferably 0.05% by mass.

[0016] Ni is an element effective in improving the corrosion resistance of ferritic stainless steel materials and the toughness of welded parts. If the Ni content is too high, the ferrite phase becomes unstable and the manufacturing cost also increases. Therefore, the upper limit value of the Ni content is controlled to 0.60% by mass, preferably 0.58% by mass, more preferably 0.55% by mass. On the other hand, the lower limit value of the Ni content is not particularly limited, but from the viewpoint of obtaining the above effects, it is preferably 0.01% by mass, more preferably 0.05% by mass.

[0017] P is an element that affects properties such as the weldability and workability of ferritic stainless steel materials. If the P content is too high, the above properties may deteriorate. Therefore, the upper limit value of the P content is controlled to 0.05% by mass, preferably 0.045% by mass, more preferably 0.04% by mass. On the other hand, the lower limit value of the P content is not particularly limited, but reducing the P content leads to an increase in refining cost. Therefore, the lower limit value of the P content is preferably 0.001% by mass, more preferably 0.01% by mass.

[0018] S is an element that generates MnS which serves as a corrosion initiation point and affects properties such as the toughness of the welded part of ferritic stainless steel materials. If the S content is too high, the above properties may deteriorate. Therefore, the upper limit value of the S content is controlled to 0.03% by mass, preferably 0.025% by mass, more preferably 0.02% by mass. On the other hand, the lower limit value of the S content is not particularly limited, but reducing the S content leads to an increase in refining cost. Therefore, the lower limit value of the S content is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more.

[0019] Cr is an element effective in improving the corrosion resistance and oxidation resistance of ferritic stainless steel materials. If the Cr content is too high, the toughness of the ferritic stainless steel material will decrease, and it will lead to an increase in manufacturing costs. Therefore, the upper limit value of the Cr content is 24.0% by mass, preferably 23.5% by mass, more preferably 23.0% by mass. On the other hand, if the Cr content is too low, the above effects may not be fully obtained. Therefore, the lower limit value of the Cr content is 10.5% by mass, preferably 11.0% by mass.

[0020] N is an element that affects properties such as intergranular corrosion resistance (sensitization suppression effect) and workability. If the N content is too high, the workability and intergranular corrosion resistance of the ferritic stainless steel material will decrease. Therefore, the upper limit value of the N content is controlled to 0.03% by mass, preferably 0.028% by mass, more preferably 0.025% by mass. On the other hand, the lower limit value of the N content is not particularly limited, but reducing the N content will lead to an increase in refining costs. Therefore, the lower limit value of the N content is preferably 0.0005% by mass, preferably 0.001% by mass.

[0021] Cu is an element effective in improving the corrosion resistance of ferritic stainless steel materials. If the Cu content is too high, the ferrite phase will become unstable and the manufacturing cost will also increase. Therefore, the upper limit value of the Cu content is controlled to 0.60% by mass, preferably 0.55% by mass, more preferably 0.50% by mass. On the other hand, the lower limit value of the Cu content is not particularly limited, but preferably 0.001% by mass, preferably 0.01% by mass.

[0022] Mo is an element effective in improving the corrosion resistance and oxidation resistance of ferritic stainless steel materials. If the Mo content is too high, the workability of the ferritic stainless steel material will decrease and the manufacturing cost will increase. Therefore, the upper limit value of the Mo content is controlled to 2.5% by mass, preferably 2.3% by mass, more preferably 2.0% by mass. On the other hand, the lower limit value of the Mo content is not particularly limited, but preferably 0.001% by mass, preferably 0.01% by mass.

[0023] Si and Al are elements effective in improving the vibration damping property of ferritic stainless steel materials. If the Si content is too high, the workability of ferritic stainless steel materials and the toughness of the welded part will decrease. Therefore, the upper limit value of the Si content is controlled to 3.0% by mass, preferably 2.8% by mass, more preferably 2.5% by mass. Also, if the Al content is too high, the toughness of ferritic stainless steel materials will decrease. Therefore, the upper limit value of the Al content is controlled to 5.0% by mass, preferably 4.5% by mass, more preferably 4.0% by mass. The contents of Si and Al are not particularly limited, but from the viewpoint of stably improving the vibration damping property of ferritic stainless steel materials, the total content of Al and Si is preferably 1.0% by mass or more, more preferably 1.2% by mass or more, still more preferably 1.5% by mass or more.

[0024] Nb and Ti are elements that affect properties such as intergranular corrosion resistance (sensitization suppression effect). If the Nb content is too high, the workability and toughness of ferritic stainless steel materials will decrease. Therefore, the upper limit value of the Nb content is controlled to 0.50% by mass, preferably 0.48% by mass, more preferably 0.45% by mass. Also, if the Ti content is too high, the workability and surface quality of ferritic stainless steel materials will decrease. Therefore, the upper limit value of the Ti content is controlled to 0.50% by mass, preferably 0.48% by mass, more preferably 0.45% by mass. On the other hand, the lower limit values of the Nb and Ti contents are controlled in relation to the contents of C and N that reduce intergranular corrosion resistance. Specifically, the lower limit value of the total content of Nb and Ti is controlled to 6(C + N), preferably 7(C + N). Here, C and N represent the contents of C and N, respectively.

[0025] Zr, Co, V, and W are elements effective in improving the oxidation resistance of ferritic stainless steel materials. If the contents of Zr, Co, V, and W are too high, the workability and toughness of the ferritic stainless steel materials will decrease, and the manufacturing cost will increase. Therefore, the upper limit values of the contents of Zr, Co, V, and W are controlled to 1.0 mass%, preferably 0.8 mass%, and more preferably 0.5 mass% respectively. On the other hand, the lower limit values of the contents of Zr, Co, V, and W are not particularly limited, but are preferably 0.001 mass% and more preferably 0.01 mass% respectively.

[0026] REM and Ca are elements effective in improving the oxidation resistance of ferritic stainless steel materials. If the contents of REM and Ca are too high, the manufacturing cost of the ferritic stainless steel materials will increase. Therefore, the upper limit values of the contents of REM and Ca are controlled to 0.10 mass%, preferably 0.08 mass%, and more preferably 0.05 mass% respectively. On the other hand, the lower limit values of REM and Ca are not particularly limited, but are preferably 0.0001 mass% and more preferably 0.003 mass% respectively.

[0027] Sn is an element effective in improving the oxidation resistance of ferritic stainless steel materials. If the content of Sn is too high, Sn will segregate and the manufacturability will decrease. Therefore, the upper limit value of the content of Sn is controlled to 0.10 mass%, preferably 0.08 mass%, and more preferably 0.05 mass%. On the other hand, the lower limit value of the content of Sn is not particularly limited, but is preferably 0.001 mass% and more preferably 0.005 mass%.

[0028] B is an element effective in improving the secondary workability of ferritic stainless steel materials. If the content of B is too high, the fatigue strength of the ferritic stainless steel materials will decrease. Therefore, the upper limit value of the content of B is controlled to 0.01 mass%, preferably 0.008 mass%, and more preferably 0.005 mass%. On the other hand, the lower limit value of the content of B is not particularly limited, but is preferably 0.0001 mass% and more preferably 0.0005 mass%.

[0029] The ferritic stainless steel material according to an embodiment of the present invention has an average grain boundary strain rate of 1% or more and less than 15%, preferably 3 to 10%. By controlling the average grain boundary strain rate within such a range, it is possible to grow coarse crystal grains by short-time heat treatment (recrystallization treatment). Since the movement of magnetic domains effective for the manifestation of vibration damping properties is hindered more as the grain boundaries are more numerous, the vibration damping properties can be enhanced by coarsening the crystal grains and reducing the grain boundaries. The average grain boundary strain rate is determined by the method of the examples described below. Although it is generally known that strain acts as a driving force for recrystallization, when the average grain boundary strain rate becomes high, after fine crystal grains grow, they grow while incorporating surrounding crystal grains, so long-time heat treatment is required.

[0030] The ferritic stainless steel material according to an embodiment of the present invention can be manufactured by melting stainless steel having the above composition, making it into a steel sheet by a conventional method, and then applying strain to the steel sheet. Specifically, first, stainless steel having the above composition is melted and forged or cast, and then hot-rolled to obtain a hot-rolled sheet. Next, annealing, pickling, and cold rolling are sequentially performed on the hot-rolled sheet to obtain a cold-rolled sheet. Next, annealing and pickling are sequentially performed on the cold-rolled sheet to obtain a cold-rolled annealed sheet. Next, strain may be introduced into the cold-rolled annealed sheet by means of light reduction application means such as a tension leveler or a skin pass so as to obtain a predetermined average grain boundary strain rate. Although strain can also be introduced by cold rolling, since the average grain boundary strain rate becomes high, it is difficult to control it to a predetermined average grain boundary strain rate. The conditions in each step may be appropriately adjusted according to the composition of the stainless steel and the like, and are not particularly limited.

[0031] The ferritic stainless steel material according to an embodiment of the present invention preferably has an average crystal grain size of 150 μm or more after recrystallization treatment. By setting the average crystal grain size within such a range, the grain boundaries can be reduced, so that the vibration damping properties can be improved. Here, the conditions for the recrystallization treatment are not particularly limited, but it is preferably a heat treatment at 900 to 1100 °C for 5 to 30 minutes. Also, the heat treatment atmosphere may be an air atmosphere or a non-oxidizing atmosphere or the like.

[0032] The ferritic stainless steel material according to the embodiment of the present invention has a loss coefficient η after the recrystallization treatment of 5×10 -4 or more, preferably 1×10 -3 or more. By setting the loss coefficient η within such a range, the vibration damping property can be improved.

[0033] Since the ferritic stainless steel material according to the embodiment of the present invention controls the composition and the average grain boundary strain rate of the ferritic stainless steel material within a predetermined range, it is possible to enhance the vibration damping property by the recrystallization treatment while suppressing thermal deformation. Therefore, this ferritic stainless steel material is suitable for use as a vibration damping member. The vibration damping member is not particularly limited and can be used for various members that require vibration damping properties in automobiles, electronic devices, and the like.

[0034] The vibration damping member according to the embodiment of the present invention includes a recrystallized material of the above ferritic stainless steel material. Since this vibration damping member uses the above ferritic stainless steel material, it has little thermal deformation and excellent vibration damping properties.

Examples

[0035] Hereinafter, the content of the present invention will be described in detail with reference to examples, but the present invention is not construed as being limited thereto.

[0036] (Examples 1 to 11 and Comparative Examples 1 to 9) A ferritic stainless steel material was produced according to the following procedure. A stainless steel having the composition shown in Table 1 was melted, hot-rolled to obtain a hot-rolled sheet with a thickness of 3.0 mm, and then the hot-rolled sheet was annealed at 1050 °C and pickled to obtain a hot-rolled annealed sheet. Next, the hot-rolled annealed sheet was cold-rolled to obtain a cold-rolled sheet with a thickness of 1.0 mm, and then the cold-rolled sheet was finish-annealed at 950 - 1050 °C and pickled to obtain a cold-rolled annealed sheet. Next, for Examples 1 to 11 and Comparative Examples 3, 4, 7, and 8, a tensile test piece with a size of 300 mm in the rolling direction (L direction) × 40 mm in the width direction (C direction) was cut out by machining, and using a tensile testing machine, strain was applied at the tensile force shown in Table 2. Note that the tensile direction was the rolling direction. Note that for Comparative Examples 1, 2, 5, 6, and 9, no strain was applied.

[0037] [Table 1]

[0038] The following evaluations were performed on the ferritic stainless steel material obtained above.

[0039] (Average grain boundary strain rate) After cutting out a 10 mm × 10 mm test piece from the ferritic stainless steel material obtained above by machining, resin embedding was performed so that the cross-section in the plate thickness direction parallel to the rolling direction became the observation surface. Next, the resin-embedded test piece was mirror-finished by wet polishing using SiC abrasive paper and diamond paste, and then polished with colloidal silica abrasive. For the test piece treated in this way, crystal orientation measurement was performed by the EBSD method. For crystal orientation measurement, an FE-SEM equipped with an OIM (Orientation Imaging Microscopy) system was used. Also, the evaluation area was a field of view with an area of 100 μm square or more, and the strain area ratio was calculated using a KAM map (Kernel Average Misorientation Map) from the measurement results. The calculation of the strain area ratio was performed in any 5 fields of view, and their average value was taken as the average grain boundary strain rate.

[0040] (Heat treatment: Recrystallization treatment) After cutting out a test piece with a width of 20 mm and a rolling direction of 270 mm from the ferrite stainless steel material obtained above by cutting, heat treatment (recrystallization treatment) was performed under the conditions shown in Table 2 in an air atmosphere. After the heat treatment, it was cooled by air cooling.

[0041] (Amount of thermal deformation) The test piece after heat treatment was placed on a flat table, and a range of 30 mm from one end (one end in the rolling direction) of the test piece was brought into contact with the table and fixed with a clamp, and the height (warp height) at which the other end (the other end in the rolling direction) floated from the table was measured. The measurement of the warp height was performed at both ends of the test piece in the rolling direction, and the average value thereof was taken as the warp height. In this evaluation, when the warp height was 5 mm or less, it was marked as ○ (small amount of thermal deformation), and when the warp height exceeded 5 mm, it was marked as × (large amount of thermal deformation).

[0042] (Average crystal grain size after heat treatment (recrystallization treatment)) After cutting out a 10 mm × 10 mm test piece from the test piece after heat treatment by cutting, resin embedding was performed so that the cross-section in the plate thickness direction parallel to the rolling direction became the observation surface. Next, the test piece subjected to resin embedding was mirror-finished by wet polishing, and the metal structure revealed by etching with hydrofluoric acid was observed with an optical microscope. The observation with the optical microscope was carried out in accordance with JIS G0551:2013. A straight line was drawn at an arbitrary position on the optical microscope image, the number of intersections between the straight line and the crystal grain boundaries was measured, and the average section length was taken as the crystal grain size. The measurement of the crystal grain size was performed by drawing 20 or more straight lines in a plurality of fields of view and measuring, and the average value thereof was taken as the average crystal grain size. In this evaluation, when the average crystal grain size was 150 μm or more, it was marked as ○ (sufficient coarsening of crystal grains), and when the average crystal grain size was less than 150 μm, it was marked as × (insufficient coarsening of crystal grains).

[0043] (Loss coefficient η after heat treatment (recrystallization treatment)) A test piece measuring 10 mm in the width direction and 250 mm in the rolling direction was cut out by machining from the heat-treated test piece. Using this test piece, the loss factor η was measured in accordance with the "central excitation method" specified in JIS K7391:2008. Specifically, the test piece with the center fixed was excited by an impedance head, and the mechanical impedance was derived from the output force signal and acceleration vibration. Then, the loss factor η was derived based on the anti-resonance frequency at which the mechanical impedance peaks and the frequency at which the amplitude drops by 3 dB from the peak. In this evaluation, when the loss factor η is 5×10 -4 or more, it is rated as ◎ (excellent vibration damping property), and when the loss factor η is 1×10 -3 or more and less than 5×10 -4 it is rated as 〇 (good vibration damping property), and when the loss factor η is less than 1×10 -3 it is evaluated as × (insufficient vibration damping property). The above evaluation results are shown in Table 2.

[0044]

Table 2

[0045] As shown in Table 2, for the ferritic stainless steel materials of Examples 1 to 11 where the average grain boundary strain rate is 1% or more and less than 15%, the results of the hot deformation amount, average crystal grain size, and loss factor η were all good. On the other hand, for the ferritic stainless steel materials of Comparative Examples 1 to 7, since the average grain boundary strain rate was outside the above range, the results of any one or more of the hot deformation amount, average crystal grain size, and loss factor η were not sufficient. Also, for the ferritic stainless steel material of Comparative Example 8, since the Cr content was too low, the result of the hot deformation amount was not sufficient. Furthermore, for the ferritic stainless steel material of Comparative Example 9, since the Cr content was too low and the average grain boundary strain rate was outside the above range, all the results of the hot deformation amount, average crystal grain size, and loss factor η were not sufficient.

[0046] As can be seen from the above results, according to the present invention, it is possible to provide a ferritic stainless steel material and a vibration damping member capable of enhancing the vibration damping property by recrystallization treatment while suppressing hot deformation.

Claims

1. A ferritic stainless steel material containing C: 0.05% by mass or less, Mn: 1.0% by mass or less, Ni: 0.60% by mass or less, P: 0.05% by mass or less, S: 0.03% by mass or less, Cr: 10.5 - 24.0% by mass, N: 0.03% by mass or less, Cu: 0.60% by mass or less, Mo: 2.5% by mass or less, Si: 3.0% by mass or less, Al: 5.0% by mass or less, with the balance being Fe and unavoidable impurities, and having an average grain boundary strain rate of 1% or more and less than 15%.

2. The ferritic stainless steel material according to Claim 1, further containing at least one selected from Nb: 0.50% by mass or less and Ti: 0.50% by mass or less, and the total content of Nb and Ti being 6(C + N) or more (where C and N represent the contents of C and N, respectively).

3. The ferritic stainless steel material according to Claim 1 or 2, wherein the total content of Al and Si is 1.0% by mass or more.

4. The ferritic stainless steel material according to any one of Claims 1 to 3, further containing at least one selected from Zr: 1.0% by mass or less, Co: 1.0% by mass or less, V: 1.0% by mass or less, and W: 1.0% by mass or less.

5. The ferritic stainless steel material according to any one of Claims 1 to 4, further containing at least one selected from REM: 0.10% by mass or less and Ca: 0.10% by mass or less.

6. The ferritic stainless steel material according to any one of Claims 1 to 5, further containing at least one selected from Sn: 0.10% by mass or less and B: 0.01% by mass or less.

7. The ferritic stainless steel material according to any one of Claims 1 to 6, having an average crystal grain size of 150 μm or more after recrystallization treatment at 900 - 1100°C for 5 - 30 minutes.

8. The ferrite stainless steel material according to any one of claims 1 to 7, wherein the loss coefficient η after recrystallization treatment at 900 to 1100°C for 5 to 30 minutes is 5×10 -4 or more.

9. The ferritic stainless steel material according to any one of Claims 1 to 8, used for a vibration damping member.

10. A method for manufacturing a vibration damping member, comprising subjecting the ferritic stainless steel material according to any one of Claims 1 to 9 to recrystallization treatment at 900 - 1100°C for 5 - 30 minutes.

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