JP3232532B2 - Austenitic stainless steel excellent in antibacterial property and method for producing the same - Google Patents
Austenitic stainless steel excellent in antibacterial property and method for producing the sameInfo
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- JP3232532B2 JP3232532B2 JP35145095A JP35145095A JP3232532B2 JP 3232532 B2 JP3232532 B2 JP 3232532B2 JP 35145095 A JP35145095 A JP 35145095A JP 35145095 A JP35145095 A JP 35145095A JP 3232532 B2 JP3232532 B2 JP 3232532B2
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Description
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【産業上の利用分野】本発明は、厨房機器，電気機器，
建築材料，機械機器，化学機器等の広範囲な分野におい
て抗菌性が必要とされる用途に適したオーステナイト系
ステンレス鋼及びその製造方法に関する。The present invention relates to kitchen appliances, electric appliances,
The present invention relates to an austenitic stainless steel suitable for applications requiring antibacterial properties in a wide range of fields such as building materials, mechanical devices, and chemical devices, and a method for producing the same.
【０００２】[0002]
【従来の技術】厨房機器，病院等で使用されている各種
機材や、バス，電車等の輸送機関の手摺り用パイプ等で
は、一般環境における耐食性が要求されるため、ＳＵＳ
３０４に代表されるステンレス鋼が主として使用されて
いる。しかし、黄色ブドウ球菌等による院内感染が問題
となってきている昨今、バス，電車等の不特定多数の人
間が利用する環境においても衛生面の向上が求められて
いる。これに伴って、各種機械，器具に使用される材料
としても、一般構造材としての特性に止まらず、定期的
な消毒等の感染防止を図る必要がない抗菌性等の機能を
付与したメンテナンスフリーの材料が望まれている。抗
菌性を付与した材料としては、特開平５−２２８２０２
号公報，特開平６−１０１９１号公報等で開示されてい
るように、有機皮膜やめっきによる抗菌コートが一般的
であった。2. Description of the Related Art Corrosion resistance in general environments is required for various equipment used in kitchen equipment and hospitals, and handrail pipes for transportation such as buses and trains.
Stainless steel represented by 304 is mainly used. However, recently, in-hospital infections caused by Staphylococcus aureus and the like have become a problem, and there is a demand for improved hygiene even in an environment used by an unspecified number of people such as buses and trains. Along with this, the materials used for various machines and instruments are not limited to the properties of general structural materials, and are maintenance-free with functions such as antibacterial properties that do not require regular disinfection and other infection prevention. Material is desired. JP-A-5-228202 discloses a material having antibacterial properties.
As disclosed in Japanese Unexamined Patent Application Publication No. Hei 6-10191, an organic film and an antibacterial coat by plating are generally used.
【０００３】[0003]
【発明が解決しようとする課題】しかし、抗菌コート
は、皮膜の消失に応じて抗菌性が低下する欠点がある。
抗菌性が消失した有機質は、栄養源となり却って細菌や
雑菌を繁殖させる虞れもある。抗菌剤成分を混入した複
合めっきを施したものでは、めっき層の密着性が十分で
なく、加工性を低下させる欠点がある。また、皮膜の溶
解，摩耗，欠損等に起因して外観が低下すると共に、抗
菌作用が低下する場合がある。ところで、Ａｇ，Ｃｕ等
の金属元素は、有効な抗菌作用を発揮することが知られ
ている。しかし、Ａｇは、非常に高価で耐食性にも劣っ
ていることから、腐食が予想される環境に曝される用途
で使用されていない。他方、Ｃｕは比較的安価な元素で
あり抗菌成分としても有効なことから、ステンレス鋼等
の材料に添加して抗菌性を付与することが検討されてい
る。However, the antibacterial coat has a drawback that the antibacterial property is reduced as the film disappears.
The organic matter having lost the antibacterial property may become a nutrient source and may propagate bacteria and various bacteria. In the case of applying a composite plating mixed with an antibacterial agent component, the adhesion of the plating layer is not sufficient, and there is a drawback that the workability is reduced. In addition, the appearance may be deteriorated due to the dissolution, abrasion, chipping or the like of the film, and the antibacterial effect may be reduced. Incidentally, it is known that metal elements such as Ag and Cu exert an effective antibacterial action. However, Ag is extremely expensive and has poor corrosion resistance, and therefore is not used in applications exposed to an environment where corrosion is expected. On the other hand, since Cu is a relatively inexpensive element and is also effective as an antibacterial component, it has been studied to add it to a material such as stainless steel to impart antibacterial properties.
【０００４】本発明者等も、Ｃｕ添加による抗菌性の改
善を種々検討し、ステンレス鋼表面のＣｕ濃度を高める
ことによって抗菌性が改善されることを見い出し、特開
平８−５３７３８号，特開平８−２２５８９５号で提案
した。本発明は、先に提案したＣｕの作用を更に高める
べく案出されたものであり、Ｃｕを主体とする第２相
（以下、Ｃｕリッチ相という）を所定量析出させること
により、優れた抗菌性をオーステナイト系ステンレス鋼
に付与することを目的とする。The present inventors have also studied various improvements in antibacterial properties by adding Cu, and found that the antibacterial properties can be improved by increasing the Cu concentration on the surface of stainless steel. No. 8-225895. The present invention has been devised in order to further enhance the action of Cu previously proposed. By precipitating a predetermined amount of a second phase mainly composed of Cu (hereinafter, referred to as a Cu-rich phase), an excellent antibacterial property is obtained. It is intended to impart the property to austenitic stainless steel.
【０００５】[0005]
【課題を解決するための手段】本発明のオーステナイト
系ステンレス鋼は、その目的を達成するため、Ｃ：０．
１重量％以下，Ｓｉ：２重量％以下，Ｍｎ：５重量％以
下，Ｃｒ：１０〜３０重量％，Ｎｉ：５〜１５重量％及
びＣｕ：１．０〜５．０重量％を含み、残部が実質的に
Ｆｅの組成をもち、時効処理で析出したＣｕリッチ相が
０．２体積％以上の割合でマトリックスに分散している
ことを特徴とする。このオーステナイト系ステンレス鋼
は、更にＮｂ及び／又はＴｉ：０．０２〜１重量％，Ｍ
ｏ：３重量％以下，Ａｌ：１重量％以下，Ｚｒ：１重量
％以下，Ｖ：１重量％以下，Ｂ：０．０５重量％以下及
び希土類元素（ＲＥＭ）：０．０５重量％以下の１種又
は２種以上を含むことができる。Ｃｕリッチ相は、所定
組成をもつオーステナイト系ステンレス鋼を熱間圧延後
から最終製品となるまでの間に５００〜９００℃の温度
範囲で時効処理を１回以上施すことにより、マトリック
ス中に分散析出する。SUMMARY OF THE INVENTION The austenitic stainless steel of the present invention has a C content of 0.1%.
1% by weight or less, Si: 2% by weight or less, Mn: 5% by weight or less, Cr: 10 to 30% by weight, Ni: 5 to 15% by weight, and Cu: 1.0 to 5.0% by weight, with the balance being the balance Has a substantially Fe composition, and is characterized in that the Cu-rich phase precipitated by the aging treatment is dispersed in the matrix at a rate of 0.2% by volume or more. This austenitic stainless steel further contains Nb and / or Ti: 0.02 to 1% by weight, M
o: 3% by weight or less, Al: 1% by weight or less, Zr: 1% by weight or less, V: 1% by weight or less, B: 0.05% by weight or less, and rare earth element (REM): 0.05% by weight or less One or more kinds can be included. The Cu-rich phase is dispersed and precipitated in the matrix by subjecting an austenitic stainless steel having a predetermined composition to an aging treatment at least once in a temperature range of 500 to 900 ° C. from after hot rolling to a final product. I do.
【０００６】[0006]
【作用】ステンレス鋼は、不動態皮膜と称されるＣｒを
主とする水酸化物で表面が覆われていることから、優れ
た耐食性を呈する。本発明者等は、有効な抗菌性を発現
するＣｕをオーステナイト系ステンレス鋼に添加し、不
動態皮膜中に含まれるＣｕ量を測定すると共に、黄色ブ
ドウ球菌を含む液の滴下による抗菌性を調査した。その
結果、ある程度以上のＣｕを含有させたステンレス鋼
は、抗菌性を備えていることが判った。しかし、鋼中に
数％以下のＣｕを単に固溶させただけでは、抗菌性及び
その持続性が必ずしも十分ではない場合がある。そこ
で、更に検討を重ねた結果、同一のＣｕ含有量であって
も、Ｃｕの一部がε−Ｃｕ等のＣｕリッチ相として微細
に且つ均一に析出していると、使用環境においてＣｕの
溶出が容易になり、抗菌性が改善されることを知見し
た。また、加工又は使用中に表面が損耗を受けたとして
も、内部のＣｕリッチ相が新規表面に現れるため、抗菌
持続性にも優れている。The stainless steel has excellent corrosion resistance because its surface is covered with a hydroxide mainly composed of Cr called a passive film. The present inventors have added Cu exhibiting effective antibacterial properties to austenitic stainless steel, measured the amount of Cu contained in the passive film, and investigated the antibacterial properties by dropping a liquid containing Staphylococcus aureus. did. As a result, it was found that stainless steel containing Cu to a certain degree or more had antibacterial properties. However, merely dissolving a few percent or less of Cu in steel may not always have sufficient antibacterial properties and durability. Therefore, as a result of further study, even if the Cu content is the same, if a part of Cu is finely and uniformly precipitated as a Cu-rich phase such as ε-Cu, the elution of Cu in the use environment And the antibacterial property was improved. Moreover, even if the surface is worn during processing or use, the internal Cu-rich phase appears on the new surface, so that the antibacterial durability is excellent.
【０００７】Ｃｕリッチ相を析出させる手段としては、
Ｃｕリッチ相が析出し易い温度領域で時効等の等温加熱
を施すこと，徐冷により析出温度域の通過時間をできる
だけ長くすること等が考えられる。そこで、種々の条件
について検討した結果、最終焼鈍後に５００〜９００℃
の範囲で時効処理すると析出が促進され、Ｃｕ添加量が
低い場合でも良好な抗菌性が得られることを見い出し
た。また、Ｔｉ，Ｎｂ，Ｍｏ等の炭窒化物や析出物を形
成し易い元素を添加すると、これら析出物等の析出サイ
トとしてＣｕリッチ相がマトリックスに均一分散し易
く、抗菌性及び製造性が改善される。また、Ｃｕの一部
がＣｕリッチ相として析出していると、表面のＣｕ濃度
が上昇すると共に、抗菌性も改善される。As means for precipitating a Cu-rich phase,
It is conceivable that isothermal heating such as aging is performed in a temperature range where the Cu-rich phase is likely to precipitate, and that the passage time in the precipitation temperature range is made as long as possible by slow cooling. Then, as a result of examining various conditions, after final annealing, it is 500 to 900 ° C.
It has been found that when aging treatment is carried out within the range, precipitation is promoted, and good antibacterial properties can be obtained even when the Cu addition amount is low. In addition, when elements such as Ti, Nb, and Mo, which easily form carbonitrides and precipitates, are added, Cu-rich phases are easily dispersed in the matrix as precipitation sites for these precipitates and the like, and antibacterial properties and productivity are improved. Is done. When a part of Cu is precipitated as a Cu-rich phase, the Cu concentration on the surface increases and the antibacterial property is improved.
【０００８】以下、本発明オーステナイト系ステンレス
鋼に含まれる合金元素及びその含有量等について説明す
る。 Ｃ：０．１重量％以下 Ｃｕリッチ相の析出サイトとして有効なＣｒ炭化物を生
成し、微細なＣｕリッチ相を均一分散させるために有効
な合金元素である。しかし、過剰に添加すると製造性や
耐食性を劣化させることから、Ｃ含有量の上限を０．１
重量％に規制した。 Ｓｉ：２重量％以下 耐食性を改善するために有効な合金元素であり、抗菌性
を向上する作用も呈する。しかし、２重量％を超える過
剰なＳｉ添加は製造性を劣化させる。Hereinafter, alloying elements contained in the austenitic stainless steel of the present invention and their contents will be described. C: 0.1% by weight or less C is an alloy element effective for generating a Cr carbide effective as a precipitation site of a Cu-rich phase and uniformly dispersing a fine Cu-rich phase. However, if added in excess, the manufacturability and corrosion resistance deteriorate, so the upper limit of the C content is 0.1%.
It was restricted to wt%. Si: 2% by weight or less Si is an alloy element effective for improving corrosion resistance, and also exhibits an action of improving antibacterial properties. However, excessive Si addition exceeding 2% by weight deteriorates the productivity.
【０００９】Ｍｎ：５重量％以下 製造性を改善すると共に、鋼中の有害なＳをＭｎＳとし
て固定する作用を呈する。また、ＭｎＳは、Ｃｕリッチ
相生成の核として作用するため、微細なＣｕリッチ相を
析出させる上でも有効な合金元素である。しかし、５重
量％を超える多量のＭｎ含有は、耐食性を劣化させる。 Ｃｒ：１０〜３０重量％ オーステナイト系ステンレス鋼の耐食性を維持するため
に必要な合金元素であり、必要な耐食性を確保する上か
ら１０重量％以上のＣｒ含有が要求される。しかし、３
０重量％を超える多量のＣｒが含まれると、製造性，加
工性が劣化する。Mn: not more than 5% by weight It has an effect of improving manufacturability and fixing harmful S in steel as MnS. In addition, MnS acts as a nucleus for generating a Cu-rich phase, and is therefore an effective alloy element for precipitating a fine Cu-rich phase. However, a large content of Mn exceeding 5% by weight deteriorates corrosion resistance. Cr: 10 to 30% by weight Cr is an alloy element necessary for maintaining the corrosion resistance of austenitic stainless steel, and is required to contain 10% by weight or more of Cr in order to secure the required corrosion resistance. But 3
If a large amount of Cr exceeding 0% by weight is contained, manufacturability and workability deteriorate.
【００１０】Ｎｉ：５〜１５重量％ オーステナイト相の安定化に重要な合金元素である。し
かし、多量添加は、高価なＮｉを消費し鋼材コストを上
昇させることから、Ｎｉ含有量の上限を１５重量％に規
制した。 Ｃｕ：１．０〜５．０重量％ 及び Ｃｕリッチ相：
０．２体積％以上 本発明のステンレス鋼において最も重要な合金元素であ
り、良好な抗菌性を維持するためには０．２体積％以上
のＣｕリッチ相が析出していることが必要であり、本系
のオーステナイト系ステンレス鋼で０．２体積％以上の
Ｃｕリッチ相を析出させるためにＣｕ含有量１．０重量
％以上が要求される。しかし、５．０重量％を超える過
剰のＣｕを含有させると、製造性，加工性，耐食性が劣
化する。Ｃｕリッチ相は、析出物の大きさが特に限定さ
れるものでないが、製品表面全体において均等に抗菌性
を発揮させるため、また研磨等が施された場合にも良好
な抗菌性を維持するためには、析出相が表面及び内部に
おいても適宜に分散して分布していることが好ましい。Ni: 5 to 15% by weight An important alloying element for stabilizing the austenite phase. However, since the addition of a large amount consumes expensive Ni and raises the cost of steel materials, the upper limit of the Ni content is restricted to 15% by weight. Cu: 1.0 to 5.0% by weight and Cu rich phase:
0.2% by volume or more It is the most important alloying element in the stainless steel of the present invention. In order to maintain good antibacterial properties, it is necessary that 0.2% by volume or more of a Cu-rich phase is precipitated. In order to precipitate a Cu-rich phase of 0.2% by volume or more in the austenitic stainless steel of the present system, a Cu content of 1.0% by weight or more is required. However, when an excessive amount of Cu exceeding 5.0% by weight is contained, manufacturability, workability, and corrosion resistance deteriorate. The Cu-rich phase is not particularly limited in the size of the precipitate, but in order to uniformly exhibit antibacterial properties over the entire product surface, and to maintain good antibacterial properties even when subjected to polishing or the like. Preferably, the precipitate phase is appropriately dispersed and distributed on the surface and inside.
【００１１】Ｎｂ：０．０２〜１重量％ Ｃｕリッチ相は、Ｎｂの析出物の周囲に析出する傾向を
示す。そのため、Ｃｕリッチ相を均一に析出させるため
には、Ｎｂの炭化物，窒化物，炭窒化物を微細に析出さ
せた組織が好ましい。しかし、過剰にＮｂを添加する
と、製造性，加工性が劣化する。このようなことから、
Ｎｂを添加する場合、０．０２〜１重量％の範囲に含有
量を調整することが好ましい。 Ｔｉ：０．０２〜１重量％ Ｎｂと同様に炭窒化物を形成し、その周囲にＣｕリッチ
相を均一析出させる作用を呈する。しかし、Ｔｉの過剰
添加は、製造性や加工性を劣化させ、製品表面に疵が発
生し易くなる。そのため、Ｔｉを添加する場合、その含
有量を０．０２〜１重量％の範囲に設定することが好ま
しい。Nb: 0.02 to 1% by weight The Cu-rich phase tends to precipitate around Nb precipitates. Therefore, in order to uniformly precipitate the Cu-rich phase, a structure in which Nb carbides, nitrides, and carbonitrides are finely precipitated is preferable. However, if Nb is excessively added, the manufacturability and workability deteriorate. From such a thing,
When adding Nb, it is preferable to adjust the content in the range of 0.02 to 1% by weight. Ti: 0.02 to 1% by weight As in the case of Nb, it forms a carbonitride and exhibits an effect of uniformly depositing a Cu-rich phase around it. However, excessive addition of Ti deteriorates manufacturability and workability, and easily causes flaws on the product surface. Therefore, when adding Ti, it is preferable to set the content in the range of 0.02 to 1% by weight.
【００１２】Ｍｏ：３重量％以下 必要に応じて添加される合金元素であり、耐食性を向上
させる作用を呈すると共に、Ｆｅ2 Ｍｏ等の金属間化合
物として析出し、微細なＣｕリッチ相の核サイトとなり
析出を容易にする。また、Ｍｏ及びＭｏを含む化合物
は、それ自体でも抗菌性を向上させる作用を呈する。し
かし、３重量％を超える過剰のＭｏ添加は、製造性及び
加工性を劣化させる。 Ａｌ：１重量％以下 Ｍｏと同様に耐食性を改善すると共に析出物を形成し、
微細なＣｕリッチ相の析出に有効な合金元素である。し
かし、Ａｌの過剰添加により製造性及び加工性が劣化す
るので、Ａｌを添加する場合その上限を１重量％に規制
する。 Ｚｒ：１重量％以下 必要に応じて添加される合金成分であり、炭窒化物を形
成し、微細なＣｕリッチ相の析出を容易にする。しか
し、過剰に添加すると、製造性，加工性が劣化する。そ
のため、Ｚｒを添加する場合、その上限を１重量％に規
制する。Mo: 3% by weight or less Mo is an alloying element that is added as necessary, exhibits an effect of improving corrosion resistance, and precipitates as an intermetallic compound such as Fe 2 Mo to form a fine Cu-rich phase nucleus site. And facilitates precipitation. In addition, Mo and a compound containing Mo exhibit an action of improving antibacterial properties by themselves. However, excessive Mo addition exceeding 3% by weight deteriorates the manufacturability and processability. Al: 1% by weight or less Like Mo, improves corrosion resistance and forms precipitates,
It is an effective alloy element for the precipitation of a fine Cu-rich phase. However, excessive addition of Al deteriorates manufacturability and workability. Therefore, when Al is added, the upper limit is restricted to 1% by weight. Zr: 1% by weight or less Zr is an alloy component added as needed, forms a carbonitride, and facilitates precipitation of a fine Cu-rich phase. However, if it is added excessively, the manufacturability and workability deteriorate. Therefore, when Zr is added, the upper limit is restricted to 1% by weight.
【００１３】Ｖ：１重量％以下 Ｚｒと同様に炭窒化物を形成し、微細なＣｕリッチ相の
析出を容易にする。しかし、過剰に添加すると、製造
性，加工性が劣化する。そのため、Ｖを添加する場合、
その上限を１重量％に規制する。 Ｂ：０．０５重量％ 必要に応じて添加される合金成分であり、熱間加工性を
改善すると共に、析出物となってマトリックスに分散す
る。しかし、過剰に添加すると熱間加工性が劣化するの
で、Ｂを添加する場合その上限を０．０５重量％に規制
する。 希土類元素（ＲＥＭ）：０．０５重量％以下 必要に応じて添加される合金成分であり、適量の添加で
Ｂと同様に熱間加工性が改善される。また、Ｃｕリッチ
相の析出に有効な析出物となってマトリックスに分散す
る。しかし、過剰に添加すると熱間加工性が劣化するの
で、ＲＥＭを添加する場合その上限を０．０５重量％に
規制する。V: 1 wt% or less Carbon nitrides are formed in the same manner as Zr, thereby facilitating the precipitation of a fine Cu-rich phase. However, if it is added excessively, the manufacturability and workability deteriorate. Therefore, when V is added,
The upper limit is restricted to 1% by weight. B: 0.05% by weight An alloy component added as necessary, which improves hot workability and is dispersed as a precipitate in a matrix. However, if added excessively, hot workability deteriorates. Therefore, when B is added, the upper limit is restricted to 0.05% by weight. Rare earth element (REM): 0.05% by weight or less It is an alloy component added as needed. Hot workability is improved as in B by adding an appropriate amount. Further, it becomes a precipitate effective for the precipitation of the Cu-rich phase and is dispersed in the matrix. However, if added excessively, hot workability deteriorates. Therefore, when REM is added, the upper limit is regulated to 0.05% by weight.
【００１４】熱処理温度：５００〜９００℃ Ｃｕリッチ相を析出させるためには、５００〜９００℃
の時効処理が有効である。時効処理温度が低くなるほ
ど、マトリックス中の固溶Ｃｕ量が少なくなり、Ｃｕリ
ッチ相の析出量が多くなる。しかし、低過ぎる時効処理
温度では、拡散速度が遅くなり、析出量が逆に減少す
る。温度条件を変えて種々の時効処理を施し、抗菌性に
有効な温度範囲を検討した結果、５００〜９００℃の温
度範囲で１時間以上の時効処理を施すことが工業的に有
効な温度範囲であることが判った。この時効処理は、熱
延後から最終製品となるまでの何れの段階で施しても有
効である。Heat treatment temperature: 500-900 ° C. In order to precipitate a Cu-rich phase, 500-900 ° C.
Is effective. The lower the aging temperature, the lower the amount of solute Cu in the matrix and the greater the amount of Cu-rich phase deposited. However, if the aging treatment temperature is too low, the diffusion rate becomes slow, and the amount of precipitation decreases on the contrary. As a result of examining the temperature range effective for antibacterial properties by performing various aging treatments by changing temperature conditions, it is possible to perform aging treatment for 1 hour or more at a temperature range of 500 to 900 ° C in an industrially effective temperature range. I found it to be. This aging treatment is effective regardless of the stage after the hot rolling to the final product.
【００１５】[0015]
【実施例】表１に示した組成を持つオーステナイト系ス
テンレス鋼を３０ｋｇ真空溶解炉で溶製し、鍛造及び熱
延後に焼鈍又は時効処理を施し、熱延焼鈍板を得た。そ
して、冷延及び焼鈍を繰り返し施し、最終的に板厚０．
７ｍｍの冷延焼鈍板を得た。熱延後に時効処理を施さな
かった板については、最終焼鈍後に時効処理を施した。
なお、熱延後及び最終焼鈍後の時効処理時間は、１００
時間に設定した。得られた供試材を透過型電子顕微鏡で
観察し、Ｃｕリッチ相の析出量を定量した。また、各試
験片を、次の抗菌性試験に供した。Ｓｔａｐｈｙｌｏｃ
ｏｃｕｓａｕｒｅｕｓ ＩＦＯ１２７３２（黄色ブドウ
球菌）を普通ブイヨン培地で３５℃，１６〜２４時間振
盪培養し、培養液を用意した。培養液を滅菌リン酸緩衝
液で２０，０００倍に希釈し、菌液を調製した。５ｃｍ
×５ｃｍの試験片を＃４００研磨した表面に菌液１ｍｌ
を滴下し、２５℃で２４時間保存した。保存後、試験片
をＳＣＤＬＰ培地（日本製薬株式会社製）９ｍｌで洗い
流し、得られた液について標準寒天培地を用いた混釈平
板培養法（３５℃，２日間培養）で生菌数をカウントし
た。また、参照としてシャーレに菌液を直接滴下し、同
様に生菌数をカウントした。EXAMPLES 30 kg of austenitic stainless steel having the composition shown in Table 1 was melted in a vacuum melting furnace, and subjected to annealing or aging treatment after forging and hot rolling to obtain a hot-rolled annealed plate. Then, cold rolling and annealing are repeatedly performed, and finally the sheet thickness is reduced to 0.1 mm.
A 7 mm cold-rolled annealed plate was obtained. For the sheet that was not subjected to the aging treatment after the hot rolling, the aging treatment was performed after the final annealing.
The aging time after hot rolling and after final annealing is 100
Set to time. The obtained test material was observed with a transmission electron microscope, and the amount of precipitated Cu-rich phase was quantified. In addition, each test piece was subjected to the following antibacterial test. Staphyloc
Ocusaureus IFO12732 (Staphylococcus aureus) was cultured with shaking in a normal broth medium at 35 ° C. for 16 to 24 hours to prepare a culture solution. The culture was diluted 20,000-fold with sterile phosphate buffer to prepare a bacterial solution. 5cm
× 5cm test piece # 400 polished surface 1ml of bacterial solution
Was added dropwise and stored at 25 ° C. for 24 hours. After storage, the test piece was washed off with 9 ml of SCDLP medium (manufactured by Nippon Pharmaceutical Co., Ltd.), and the number of viable cells was counted on the obtained liquid by a pour plate method (cultured at 35 ° C. for 2 days) using a standard agar medium. . Further, as a reference, a bacterial solution was directly dropped on a petri dish, and the number of viable bacteria was similarly counted.
【００１６】生菌が検出されなかったものを◎，参照の
生菌数と比較して９５％以上が死滅したものを○，６０
〜９５％未満の範囲で死滅したものを△，６０％未満の
死滅量であったものを×として評価した。抗菌性の評価
結果を、析出Ｃｕ量と併せて表１に示す。表１にみられ
るように、１．０重量％以上のＣｕが添加され、且つＣ
ｕリッチ相の析出量が０．２体積％以上の試験番号１〜
１３では、何れも良好な抗菌性が示されている。これに
対し、Ｃｕ含有量が１．０重量％以上であっても時効処
理を施さない試験番号１８では、Ｃｕリッチ相の析出量
が０．２体積％に満たず、抗菌性が劣っていた。また、
Ｃｕリッチ相の析出量は、試験番号１７や１５，１６に
みられるように、時効処理温度が５００℃未満又は９０
０℃を超えると０．２体積％未満となっていた。このこ
とから、抗菌性の改善には、Ｃｕ含有量１．０重量％以
上で且つＣｕリッチ相析出量０．２体積％以上が必要で
あることが判る。また、Ｃｕリッチ相析出量０．２体積
％以上を得るためには、５００〜９００℃の時効処理が
有効であることが判る。A sample in which no viable cells were detected was indicated by ◎, and a sample in which 95% or more of the cells were killed as compared with the reference viable cell count was indicated by ○, 60
Those killed in a range of less than 95% were evaluated as Δ, and those killed in less than 60% were evaluated as x. Table 1 shows the evaluation results of the antibacterial properties together with the amount of precipitated Cu. As seen in Table 1, 1.0% by weight or more of Cu was added and C
Test Nos. 1 to 4 in which the amount of precipitation of the u-rich phase is 0.2% by volume or more
No. 13 shows good antibacterial properties. In contrast, in Test No. 18 in which the aging treatment was not performed even when the Cu content was 1.0% by weight or more, the amount of the Cu-rich phase deposited was less than 0.2% by volume, and the antibacterial properties were poor. . Also,
As can be seen in Test Nos. 17, 15, and 16, the amount of the Cu-rich phase precipitated was less than 500 ° C. or less than 90 ° C.
When the temperature exceeded 0 ° C., it was less than 0.2% by volume. From this, it is understood that the improvement of the antibacterial property requires the Cu content of 1.0% by weight or more and the Cu-rich phase precipitation of 0.2% by volume or more. In addition, it can be seen that aging treatment at 500 to 900 ° C. is effective in obtaining a Cu-rich phase precipitation amount of 0.2% by volume or more.
【００１７】[0017]
【表１】 [Table 1]
【００１８】[0018]
【発明の効果】以上に説明したように、本発明のオース
テナイト系ステンレス鋼は、Ｃｕ含有量が１．０重量％
以上で且つＣｕリッチ相析出量が０．２体積％以上であ
ることから、無垢材でも優れた抗菌性を発揮する。この
抗菌性は、材質に由来するので、長期間にわたって持続
する。そのため、このステンレス鋼は、厨房機器，病院
等で使用される各種機材，電車，バス等の輸送機関にお
いて人体が接触する機器等の材料として、抗菌性が要求
される広範な分野において使用され、生活環境の改善が
図られる。As described above, the austenitic stainless steel of the present invention has a Cu content of 1.0% by weight.
As described above, since the Cu-rich phase precipitation amount is 0.2% by volume or more, excellent antibacterial properties are exhibited even with a solid material. Since this antibacterial property is derived from the material, it lasts for a long time. Therefore, this stainless steel is used in a wide range of fields where antibacterial properties are required, such as kitchen equipment, various equipment used in hospitals, etc., and equipment that comes into contact with the human body in transportation such as trains and buses. The living environment is improved.
フロントページの続き (72)発明者 中村 定幸 山口県新南陽市野村南町4976番地 日新 製鋼株式会社 技術研究所内 (56)参考文献 特開 平６−17197（ＪＰ，Ａ) 特開 平６−134503（ＪＰ，Ａ) 特開 平７−188740（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C22C 38/00 - 38/60 C21D 9/46 Continuation of front page (72) Inventor Sadayuki Nakamura 4976 Nomura Minamicho, Shinnanyo-shi, Yamaguchi Prefecture Nissin Steel Works, Ltd. Technical Research Laboratory (56) References JP-A-6-17197 (JP, A) JP-A-6-134503 (JP, A) JP-A-7-188740 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C22C 38/00-38/60 C21D 9/46
Claims (2)
以下，Ｍｎ：５重量％以下，Ｃｒ：１０〜３０重量％，
Ｎｉ：５〜１５重量％及びＣｕ：１．０〜５．０重量％
を含み、残部が実質的にＦｅの組成をもち、時効処理で
析出したＣｕリッチ相が０．２体積％以上の割合でマト
リックスに分散している抗菌性に優れたオーステナイト
系ステンレス鋼。1. C: 0.1% by weight or less, Si: 2% by weight
Mn: 5% by weight or less, Cr: 10 to 30% by weight,
Ni: 5 to 15% by weight and Cu: 1.0 to 5.0% by weight
Austenite excellent in antibacterial properties, in which the balance is substantially Fe, and the Cu-rich phase precipitated by aging is dispersed in the matrix at a rate of 0.2% by volume or more.
Series stainless steel.
ト系ステンレス鋼を熱間圧延後から最終製品となるまで
の間に５００〜９００℃の温度範囲で時効処理を１回以
上施し、０．２体積％以上の割合でＣｕリッチ第２相を
析出させることを特徴とする抗菌性に優れたオーステナ
イト系ステンレス鋼の製造方法。Subjecting 2. A method according to claim 1 austenitic stainless steel having the composition described in the temperature range of 500 to 900 ° C. until a final product after hot rolling to an aging treatment at least once, 0.2 Cu-rich second phase at a rate of at least volume%
A method for producing an austenitic stainless steel having excellent antibacterial properties, characterized by being precipitated .
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35145095A JP3232532B2 (en) | 1995-12-26 | 1995-12-26 | Austenitic stainless steel excellent in antibacterial property and method for producing the same |
| MYPI96005208A MY118759A (en) | 1995-12-15 | 1996-12-11 | Use of a stainless steel as an anti-microbial member in a sanitary environment |
| KR1019960064591A KR100313171B1 (en) | 1995-12-15 | 1996-12-12 | How to use stainless steel with improved antibacterial properties |
| EP96120116A EP0779374B1 (en) | 1995-12-15 | 1996-12-13 | Use of a stainless steel as an anti-microbial member in a sanitary environment |
| ES96120116T ES2192598T3 (en) | 1995-12-15 | 1996-12-13 | USE OF A STAINLESS STEEL AS ANTIMICROBIAL MEMBER IN A SANITARY ENVIRONMENT. |
| US08/766,788 US5861068A (en) | 1995-12-15 | 1996-12-13 | Method of using stainless steel having anti-microbial property |
| DE69626938T DE69626938T2 (en) | 1995-12-15 | 1996-12-13 | Use of stainless steel as an antimicrobial object in a sanitary environment |
| CN96114349A CN1072732C (en) | 1995-12-15 | 1996-12-13 | Stainless steel improved in anti-microbial property and manufacturing thereof |
| CN00128266A CN1111614C (en) | 1995-12-15 | 2000-12-14 | Antibiotic parts and its producing process |
| CN00128267A CN1107121C (en) | 1995-12-15 | 2000-12-14 | Antibiotic parts and its producing process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35145095A JP3232532B2 (en) | 1995-12-26 | 1995-12-26 | Austenitic stainless steel excellent in antibacterial property and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09176800A JPH09176800A (en) | 1997-07-08 |
| JP3232532B2 true JP3232532B2 (en) | 2001-11-26 |
Family
ID=18417374
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35145095A Expired - Fee Related JP3232532B2 (en) | 1995-12-15 | 1995-12-26 | Austenitic stainless steel excellent in antibacterial property and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3232532B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002241900A (en) | 1997-08-13 | 2002-08-28 | Sumitomo Metal Ind Ltd | Austenitic stainless steel having excellent sulfuric acid corrosion resistance and workability |
| BR9806903A (en) | 1997-11-14 | 2000-05-16 | Sumitomo Osaka Cement Co Ltd | Method for producing an antibacterial metallic article and an antibacterial metallic article such as this produced by that method |
| JP3398591B2 (en) * | 1998-03-16 | 2003-04-21 | 川崎製鉄株式会社 | Stainless steel material excellent in antibacterial property and method for producing the same |
| JP4374320B2 (en) | 2005-02-28 | 2009-12-02 | 新日本製鐵株式会社 | Steel with excellent resistance to sulfuric acid dew point corrosion |
| CN102220473A (en) * | 2010-04-14 | 2011-10-19 | 元能股份有限公司 | Antimicrobial stainless steel wire and manufacturing method thereof |
| WO2022202507A1 (en) | 2021-03-26 | 2022-09-29 | 日鉄ステンレス株式会社 | Stainless steel material and method for manufacturing same, and antibacterial/antiviral member |
-
1995
- 1995-12-26 JP JP35145095A patent/JP3232532B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09176800A (en) | 1997-07-08 |
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