JP3008798B2 - Ferritic stainless steel for molten carbonate fuel cells - Google Patents
Ferritic stainless steel for molten carbonate fuel cellsInfo
- Publication number
- JP3008798B2 JP3008798B2 JP7001281A JP128195A JP3008798B2 JP 3008798 B2 JP3008798 B2 JP 3008798B2 JP 7001281 A JP7001281 A JP 7001281A JP 128195 A JP128195 A JP 128195A JP 3008798 B2 JP3008798 B2 JP 3008798B2
- Authority
- JP
- Japan
- Prior art keywords
- molten carbonate
- stainless steel
- steel
- corrosion
- corrosion resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
- H01M8/0204—Non-porous and characterised by the material
- H01M8/0206—Metals or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/14—Fuel cells with fused electrolytes
- H01M2008/147—Fuel cells with molten carbonates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0048—Molten electrolytes used at high temperature
- H01M2300/0051—Carbonates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
- H01M8/0204—Non-porous and characterised by the material
- H01M8/0206—Metals or alloys
- H01M8/0208—Alloys
- H01M8/021—Alloys based on iron
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Description
【０００１】本発明は、溶融炭酸塩型燃料電池用フェラ
イト系ステンレス鋼に関する。The present invention relates to a ferritic stainless steel for a molten carbonate fuel cell .
【０００２】[0002]
【従来の技術】２１世紀における石油資源枯渇と大気汚
染等の環境問題より、次世代の電力供給源として、石炭
改質ガスを利用することができる燃料電池が脚光を浴び
始めている。燃料電池は起電力を発生する電解質によっ
てリン酸型、溶融炭酸塩型、固体電解質型などの種類が
あり、各々運転温度、発電効率が異なる。このうち、Ｌ
ＮＧと石炭改質ガスを利用する溶融炭酸塩型燃料電池は
分散型電源やガスタービンとの複合発電による大規模集
中型電源として注目されている。現在１００ｋＷ級スタ
ックの開発が終了し、１ＭＷ級のプラントに着手されて
いる。2. Description of the Related Art Due to environmental problems such as depletion of petroleum resources and air pollution in the 21st century, fuel cells that can utilize coal reformed gas as a next-generation power supply source have begun to attract attention. Fuel cells are of a phosphoric acid type, a molten carbonate type, a solid electrolyte type, and the like, depending on the electrolyte that generates the electromotive force, and each has a different operating temperature and power generation efficiency. Of these, L
Molten carbonate fuel cells using NG and coal reformed gas have attracted attention as a large-scale centralized power supply using a distributed power supply or combined power generation with a gas turbine. At present, development of a 100 kW class stack has been completed, and a 1 MW class plant has been started.
【０００３】しかしながら、このような大型化を実現
し、商用プラントとして実用化するためには装置の長時
間の安定性と信頼性、さらには低コスト化が重要とな
る。[0003] However, in order to realize such a large-sized device and put it into practical use as a commercial plant, it is important to ensure long-term stability and reliability of the device and to reduce the cost.
【０００４】現状での一つの大きな問題として、電解質
である溶融炭酸塩による金属材料の腐食がある。特に、
600〜 700℃の高温の溶融炭酸塩に接するセパレータ材
や集電板は激しい腐食環境にさらされ、電池の寿命劣化
の要因となっている。[0004] One major problem at the present time is the corrosion of metallic materials by molten carbonate as an electrolyte. In particular,
The separator material and current collector that come into contact with the molten carbonate at a high temperature of 600-700 ° C are exposed to a severely corrosive environment, which is a factor in shortening the battery life.
【０００５】従来セパレータ材には、SUS316L(Fe-17Cr-
12Ni-2.5Mo) やSUS310S(Fe-25Cr-20Ni) が用いられてき
たが、耐食性は充分でない。Conventional separator materials include SUS316L (Fe-17Cr-
12Ni-2.5Mo) and SUS310S (Fe-25Cr-20Ni) have been used, but their corrosion resistance is not sufficient.
【０００６】溶融炭酸塩に対する耐食性の改善策とし
て、特公平4-37154 号公報には 1〜 2％のAlを添加する
こと、特開昭63-190143 号公報には 0.1〜 0.9％のAlと
Y を複合添加することが開示されており、また特開平1ー
252750号公報、特開平1-252757号公報にはSi量を 0.2％
以下に規制し、かつAlを添加したステンレス鋼及びＮｉ
基合金が開示されている。As a measure for improving the corrosion resistance against molten carbonate, 1 to 2% of Al is added to JP-B-4-37154, and 0.1 to 0.9% of Al is added to JP-A-63-190143.
It is disclosed that Y is added in combination.
252750 JP, JP-A 1-252757 discloses that the amount of Si is 0.2%
Stainless steel and Ni with the following restrictions and Al added
A base alloy is disclosed.
【０００７】特開昭64-68449号公報ではFe、Cr、Ni量
を、特開平4-247852号公報ではCr、Ni量及びMn量を規定
したステンレス鋼が開示されている。JP-A-64-68449 discloses a stainless steel in which the amounts of Fe, Cr and Ni are specified, and JP-A-4-247852 discloses a stainless steel in which the amounts of Cr, Ni and Mn are specified.
【０００８】しかしながら、これらステンレス鋼及びＮ
ｉ基合金は、SUS316L 等の従来材に比し、溶融炭酸塩に
対する耐食性の向上が見られるものの、長時間の耐用を
考えた場合十分とは言えない。However, these stainless steels and N
The i-base alloy has an improved corrosion resistance against molten carbonates as compared with conventional materials such as SUS316L, but it cannot be said that it is sufficient when used for a long time.
【０００９】また、さらに上記の鋼はNiを含有するFe-C
r-Ni系ステンレス鋼が大半であり、コスト及び後述する
ようにNiの溶融炭酸塩腐食に及ぼす弊害を考慮した場合
満足できるものとは言えない。[0009] Further, the above steel is made of Fe-C containing Ni.
Most of them are r-Ni stainless steels, and cannot be said to be satisfactory when considering the cost and the adverse effects on molten carbonate corrosion of Ni as described later.
【００１０】[0010]
【発明が解決しようとする課題】このように溶融炭酸塩
型燃料電池に用いられる金属材料は、溶融炭酸塩中での
腐食機構が十分に解明されていないこともあり、決定的
な耐食性材料の開発が行われていないのが現状である。As described above, the metal material used for the molten carbonate fuel cell has a mechanism of corrosion in molten carbonate that has not been sufficiently elucidated. At present, there is no development.
【００１１】本発明の目的は、安価であって、耐溶融炭
酸塩腐食性に優れたステンレス鋼を提供することにあ
る。An object of the present invention is to provide a stainless steel which is inexpensive and has excellent resistance to molten carbonate corrosion.
【００１２】[0012]
【課題を解決するための手段】本発明者らは、溶融炭酸
塩環境において優れた耐食性を有し、かつ安価なステン
レス鋼の材料開発を行うに際し、Fe-Cr 系ステンレス鋼
は、Niを基本的に含有していないため安価であるこ
と、鋼中Niはカソード側雰囲気において溶解するため
長時間の耐食性劣化要因となり得ること、から従来使用
されているFe-Cr-Ni系ステンレス鋼に替わる溶融炭酸塩
型燃料電池の構成部材として有望であるとの観点から、
Fe-Cr 系ステンレス鋼について検討を行った。Means for Solving the Problems In developing a material for stainless steel which has excellent corrosion resistance in a molten carbonate environment and is inexpensive, the Fe-Cr series stainless steel is based on Ni. Because it is inexpensive because it is not chemically contained, and Ni in the steel dissolves in the cathode side atmosphere, which can be a cause of long-term corrosion resistance degradation. From the viewpoint that it is promising as a component of a carbonate fuel cell,
We studied Fe-Cr stainless steel.
【００１３】安価な Fe-Cr系ステンレス鋼の化学成分を
広範囲に変えた材料について、生成するスケールの構造
に着目し、系統的な調査、研究を重ねた結果、以下のよ
うな知見を得るに至った。[0013] As for inexpensive Fe-Cr-based stainless steel materials whose chemical components have been changed over a wide range, the following findings have been obtained as a result of repeated systematic investigations and studies, focusing on the structure of the scales produced. Reached.
【００１４】Ａ）材料表面に生成するスケールが、Cr系
主体の酸化物の場合は、電解質であるLi2CO3と容易に反
応し、LiCrO2を形成するため耐食性が劣るばかりか電解
質の損失を招くこと。A) When the scale formed on the surface of the material is a Cr-based oxide, it reacts easily with Li 2 CO 3 as an electrolyte to form LiCrO 2 , which results in poor corrosion resistance and loss of electrolyte. To invite.
【００１５】Ｂ）Cr系酸化物を生成する合金にTiを適正
量添加することにより、Cr系酸化物の内、外層側に酸化
物が形成される。内側は TiO2 内部酸化層として Cr2O3
／地金界面に存在しており、スケール密着性を高めるこ
と。B) By adding an appropriate amount of Ti to an alloy that produces a Cr-based oxide, an oxide is formed on the outer layer side of the Cr-based oxide. Inside is TiO 2 Cr 2 O 3 as internal oxide layer
/ Exists at the metal interface to enhance scale adhesion.
【００１６】Ｃ）外側は Fe-Cr系酸化物とTi系酸化物か
ら成る外層スケールが形成される。C) On the outer side, an outer layer scale composed of a Fe-Cr-based oxide and a Ti-based oxide is formed.
【００１７】これら酸化物は溶融炭酸塩に対する溶解度
が小さく、溶融炭酸塩腐食に優れた耐食性を示すこと。These oxides have low solubility in molten carbonate and exhibit excellent corrosion resistance to molten carbonate corrosion.
【００１８】Ｄ）外層スケール中のTi系酸化物が増え、
スケールの最外表面を被うTi系酸化物が増えると、溶融
炭酸塩の浸延性が抑制されること。ここに浸延性とは、
溶融炭酸塩が合金表面に付着したとき、その溶融炭酸塩
が表面を浸食しつつ周辺域に広がる現象を言う。D) Ti-based oxide in the outer layer scale increases,
As the amount of Ti-based oxide covering the outermost surface of the scale increases, the ductility of molten carbonate is suppressed. Here, the ductility is
When molten carbonate adheres to the alloy surface, it refers to the phenomenon that the molten carbonate erodes the surface and spreads to the surrounding area.
【００１９】Ｅ）Tiに加え、さらにCuを添加すると耐食
性が一層向上すること。E) Corrosion resistance is further improved by adding Cu in addition to Ti.
【００２０】本発明は、これらの知見に基づき完成させ
たものであり、その要旨とするところは、「重量%で、
C：0.08%以下、Si：0.01〜2%、Mn：1%以下、Cr：8〜19.
1%、Mo：2%以下、Ti：0.1〜3% を含み、残部実質的にFe
および不可避的不純物からなる溶融炭酸塩型燃料電池用
フェライト系ステンレス鋼、およびC：0.08%以下、Si：
0.01〜2%、Mn：1%以下、Cr：8〜22%、Mo ：2%以下、T
i：0.1〜3%、Cu：0.1〜2%を含み、残部実質的にFeおよ
び不可避的不純物からなる溶融炭酸塩型燃料電池用フェ
ライト系ステンレス鋼」にある。The present invention has been completed on the basis of these findings, and the gist of the present invention is that “% by weight,
C: 0.08% or less, Si: 0.01 to 2%, Mn: 1% or less, Cr: 8 to 19.
1%, Mo: 2% or less, Ti: 0.1 to 3 percent free free, remaining portions substantially Fe
And ferrous stainless steel for molten carbonate fuel cells comprising unavoidable impurities <br/> C: 0.08% or less, Si:
0.01 to 2%, Mn: 1% or less, Cr: 8 to 22%, Mo: 2% or less, T
i: 0.1 to 3%, Cu: 0.1 to 2%, the balance being substantially Fe and
Of molten carbonate fuel cell
Light stainless steel ".
【００２１】[0021]
【作用】以下、本発明における成分組成を限定した理由
及び作用について説明する。The reason why the composition of the present invention is limited and the function thereof will be described below.
【００２２】Ｃ：鋼中のＣは、0.08％を超えて多量にな
ると溶接部の耐食性能、溶接部及び母材の靭性に悪影響
を及ぼすため上限を0.08％とする。C: If the amount of C in the steel exceeds 0.08%, the upper limit is set to 0.08% because a large amount of C adversely affects the corrosion resistance of the welded portion and the toughness of the welded portion and the base metal.
【００２３】Ｓｉ：Siは溶解時の有効な脱酸元素であ
る。さらに溶融炭酸塩雰囲気においては、 Cr2O3／地金
界面に SiO2 を形成し、腐食を抑制する。しかしなが
ら、その含有量が 0.01％未満ではその効果がなく、一
方 2％を超えると常温での靭性及び成形性を著しく低下
させるので上限を 2％とした。Si: Si is an effective deoxidizing element during melting. Further, in a molten carbonate atmosphere, SiO 2 is formed at the Cr 2 O 3 / metal interface, thereby suppressing corrosion. However, if the content is less than 0.01%, there is no effect, while if it exceeds 2%, the toughness and formability at room temperature are remarkably reduced, so the upper limit was made 2%.
【００２４】Ｍｎ：MnはSiと同様、有益な脱酸成分であ
るが、その含有量が多いと鋼中ＳとMnS を形成し、耐食
性の劣化を招くので上限を 1％とする。Mn: Mn, like Si, is a useful deoxidizing component, but if its content is large, it forms S and MnS in steel and causes deterioration of corrosion resistance, so the upper limit is made 1%.
【００２５】Ｃｒ：Crは本発明において重要な元素の一
つである。カソード側環境において、耐溶融炭酸塩腐食
性を向上させる作用がありその効果は8%以上で発揮され
る。しかしながらCr含有量が多くなり過ぎると、表層は
Cr系主体の単一酸化スケールとなり、電解質である Li2
CO3と反応し、LiCｒO2を形成し、電解質中に溶出しやす
く、皮膜の安定性を劣化させ、また電解質の損失を招く
ことから、Crを22% 以下に制限する。好ましくは、9 〜
19.1％である。Cr: Cr is one of the important elements in the present invention. In the cathode side environment, it has the effect of improving the molten carbonate corrosion resistance, and its effect is exhibited at 8% or more. However, if the Cr content is too high, the surface layer
It becomes a Cr-based single oxide scale, and the electrolyte Li 2
Reacts with CO 3 to form LiCrO 2, which is easily eluted into the electrolyte, degrades the stability of the film, and leads to loss of the electrolyte. Therefore, the content of Cr is limited to 22% or less. Preferably, 9 to
19.1 %.
【００２６】Ｍｏ：Moは固溶強化元素として特に 600℃
以上での強度を高める効果がある。Mo: Mo is particularly 600 ° C. as a solid solution strengthening element.
This has the effect of increasing the strength.
【００２７】しかしながら、多量添加は溶融炭酸塩腐食
に対し悪影響を及ぼすこと、さらに加工性の劣化を招く
ことから上限を 2％とする。However, the addition of a large amount adversely affects the corrosion of molten carbonate and causes deterioration of workability, so the upper limit is made 2%.
【００２８】Ｔｉ：Tiは本発明において最も重要な元素
である。 0.1％以上含有させるとCr2O3 スケールの外層
側にTi系酸化物が生成され、Fe系酸化物(Fe3O4あるいは
LiFeO2) とともに混在した形態となる。これら酸化物は
溶融炭酸塩中への溶解度が小さく鋼の耐食性を向上させ
る。また、 0.1％以上のTiの含有により、Cr2O3 の内層
側の地金界面にTiO2内部酸化物が形成される。この内部
酸化物は地金側への酸素の拡散を抑制するとともに Cr2
O3／地金界面の密着性を著しく向上させる効果がある。
さらに、Ti含有量を増加させると、二層スケール外層の
Ti系酸化物の生成量が増え、Ti含有量が 0.5％程度を越
えると溶融炭酸塩の鋼表面への浸延性を阻止する効果が
顕著となり、腐食を抑制するとともに電解質である溶融
炭酸塩の損失を抑制する。しかしながらTi含有量が 3％
を越えてもそれ以上の溶融炭酸塩腐食に対する効果が認
められないばかりか、鋼表面の疵が顕著となり、また加
工性の低下が著しくなるので上限を 3％とする。好まし
くは 0.5〜 2.5％である。Ti: Ti is the most important element in the present invention. When the content is 0.1% or more, a Ti-based oxide is generated on the outer layer side of the Cr 2 O 3 scale, and the Fe-based oxide (Fe 3 O 4 or
It is mixed with LiFeO 2 ). These oxides have low solubility in the molten carbonate and improve the corrosion resistance of the steel. Further, by containing 0.1% or more of Ti, a TiO 2 internal oxide is formed at the metal interface on the inner layer side of Cr 2 O 3 . Cr 2 together with the internal oxide to suppress diffusion of oxygen to the bare metal side
This has the effect of significantly improving the adhesion at the O 3 / metal interface.
Furthermore, when the Ti content is increased,
When the amount of Ti-based oxides increases and the Ti content exceeds about 0.5%, the effect of preventing the molten carbonate from spreading on the steel surface becomes remarkable. Reduce losses. However, the Ti content is 3%
Even if it exceeds, not only no further effect on molten carbonate corrosion is recognized, but also the flaws on the steel surface become remarkable and the workability deteriorates remarkably, so the upper limit is made 3%. Preferably it is 0.5 to 2.5%.
【００２９】以上のように化学成分を制限することで溶
融炭酸塩中で優れた耐食性を有するステンレス鋼を得る
ことができるが、さらに下記に示す元素を適正量添加す
ることによりその効果を一層高める。By limiting the chemical components as described above, a stainless steel having excellent corrosion resistance in molten carbonate can be obtained, but the effect is further enhanced by adding the following elements in appropriate amounts. .
【００３０】Ｃｕ：Cuは電気化学的に貴な元素であり耐
食性を向上させるので必要により含有させるのが好まし
い。特に溶融炭酸塩雰囲気においてはTiとの複合添加に
より耐食性向上が顕著となる。この効果は 0.1％以上の
添加で発揮される。しかしながら、多量添加は鋼中で金
属間化合物を形成し逆に耐食性を劣化させるので上限を
2％とする。好ましくは 0.3〜 1.5％である。Cu: Since Cu is an electrochemically noble element and improves corrosion resistance, it is preferable to include Cu as necessary. In particular, in a molten carbonate atmosphere, the improvement of corrosion resistance becomes remarkable due to the composite addition with Ti. This effect is exhibited by adding 0.1% or more. However, the addition of a large amount forms an intermetallic compound in the steel and conversely deteriorates the corrosion resistance.
2%. Preferably it is 0.3 to 1.5%.
【００３１】[0031]
【実施例】次に、実施例により本発明を具体的に説明す
る。Next, the present invention will be described specifically with reference to examples.
【００３２】表１に示す化学組成（重量％、残部はFe）
の本発明鋼(No.1 〜12) 及び比較鋼(No.13〜20) を、高
周波電気炉（真空溶解）で溶製した。溶製した25kg鋼塊
に鍛造、熱間圧延を施し、板厚 5mmの熱延鋼板とした。Chemical composition shown in Table 1 (% by weight, balance being Fe)
Of the present invention (Nos. 1 to 12) and comparative steels (Nos. 13 to 20) were melted in a high-frequency electric furnace (vacuum melting). The wrought 25kg steel ingot was forged and hot rolled into a hot-rolled steel sheet having a thickness of 5mm.
【００３３】[0033]
【表１】 [Table 1]
【００３４】このようにして得られた熱延板を焼鈍酸洗
した後、1mm まで冷間圧延をし、970 〜1050℃(SUS310
S,SUS316Lは1150℃) で軟化焼鈍及び酸洗を行った。得
られた冷延板より厚さ1mm 、幅20mm、長さ80mmの試験片
を切り出し耐食性試験に供した。The hot-rolled sheet thus obtained was subjected to annealing and pickling, then cold-rolled to 1 mm, and heated to 970 to 1050 ° C. (SUS310
S, SUS316L was subjected to soft annealing and pickling at 1150 ° C). A test piece having a thickness of 1 mm, a width of 20 mm and a length of 80 mm was cut out from the obtained cold-rolled sheet and subjected to a corrosion resistance test.
【００３５】耐食性の試験は、試験片にLi2CO3:K2CO3=6
2:38（モル比）の混合塩を塗布し、650℃でガス組成C
O2:空気=30:70の雰囲気ガス中にて所定の時間保持し
た。In the test for corrosion resistance, the test piece was made of Li 2 CO 3 : K 2 CO 3 = 6
Apply a mixed salt of 2:38 (molar ratio) and apply gas composition C at 650 ° C
It was kept for a predetermined time in an atmosphere gas of O 2 : air = 30: 70.
【００３６】耐食性の評価は、加熱前試験片重量から脱
スケール後の試験片重量を差引いた重量減少量にて行っ
た。The corrosion resistance was evaluated by the weight loss obtained by subtracting the weight of the test piece after descaling from the weight of the test piece before heating.
【００３７】また、溶融炭酸塩の浸延性を調べるため、
試験片をワイヤで吊るし、混合塩中に半浸漬の状態で所
定の時間保持した。試験は温度及び雰囲気とも耐食性試
験と同様の条件にて実施した。塩の広がりは試験後の試
験片の気液界面から未浸漬部へ上昇する塩の状態を目視
観察にて評価し、未浸漬部への塩の上昇が小さいほど浸
延性が抑制され、長時間の溶融炭酸塩の腐食及び電解質
の損失に対して優れると判断した。Further, in order to examine the ductility of the molten carbonate,
The test piece was hung with a wire and held in a mixed salt for a predetermined time while being half-immersed. The test was performed under the same conditions as in the corrosion resistance test in both temperature and atmosphere. The spread of salt is evaluated by visual observation of the state of salt rising from the gas-liquid interface of the test specimen to the unimmersed part after the test. It was judged to be excellent for corrosion of molten carbonate and loss of electrolyte.
【００３８】図１は、溶融炭酸塩を試験片に塗布後、 6
50℃で 200時間保持した各供試材の重量減少とTi含有量
の関係を示したものである。FIG. 1 shows that after the molten carbonate was applied to the test piece,
FIG. 4 shows the relationship between the weight loss and the Ti content of each test material kept at 50 ° C. for 200 hours.
【００３９】本発明鋼No.1〜6 のようにTiを 0.1％以上
添加することにより腐食減量は低減され、耐食性に優れ
ていることが分かる。また、Cuを複合添加したNo.7〜9
はより腐食減量が小さくなる傾向にある。It can be seen that by adding 0.1% or more of Ti as in the steels Nos. 1 to 6 of the present invention, the corrosion weight loss is reduced and the corrosion resistance is excellent. In addition, Nos. 7 to 9 with complex addition of Cu
Has a tendency to reduce corrosion weight loss.
【００４０】これに対して、市販SUS316L （No.14 ）及
び比較鋼 No.19は腐食減量が非常に大きい。比較鋼 No.
17は Cu を添加しており若干腐食減量が小さくなるもの
の、Tiを 0.1％以上添加した本発明鋼に比べ耐食性は満
足なものでない。また、比較鋼No.20 はTi添加にもかか
わらずMoが多量に添加されており腐食減量が大きい。On the other hand, the commercially available SUS316L (No. 14) and the comparative steel No. 19 have very large corrosion weight loss. Comparative steel No.
In No. 17, although Cu is added, the corrosion loss is slightly reduced, but the corrosion resistance is not satisfactory as compared with the steel of the present invention containing 0.1% or more of Ti. Also, comparative steel No. 20 had a large amount of Mo added despite the addition of Ti, and the corrosion weight loss was large.
【００４１】以上からTi添加は溶融炭酸塩の腐食に対し
て有効であり、Cu添加は単独では効果が少なくTiと複合
添加することでその効果が発揮されると言える。From the above, it can be said that the addition of Ti is effective against the corrosion of molten carbonate, and the addition of Cu alone has little effect, and the effect is exhibited by adding it in combination with Ti.
【００４２】表２は、本発明鋼及び比較鋼の耐食性試験
による腐食減量と、 650℃× 200時間半浸漬試験での溶
融炭酸塩の未浸漬部への上昇の状態を評価した結果であ
る。Table 2 shows the results of evaluating the corrosion loss of the steel of the present invention and the comparative steel in the corrosion resistance test and the state of the rise of the molten carbonate to the unimmersed portion in the immersion test at 650 ° C. for 200 hours and half.
【００４３】[0043]
【表２】 [Table 2]
【００４４】本発明鋼は溶融炭酸塩の浸延性が小さく、
特にTiが 0.5％を越えると未浸漬部への上昇がほとんど
見られず、Ti添加が塩の浸延性を阻止する効果が大きい
ことが分かる。このように溶融炭酸塩の浸延性が小さい
ことは耐食性のみならず、電解質の損失を抑制すること
から電池寿命の大幅な向上が期待できる。[0044] The steel of the present invention has low ductility of molten carbonate,
In particular, when Ti exceeds 0.5%, almost no rise to the unimmersed portion is observed, and it can be seen that the addition of Ti has a large effect of inhibiting the salt elongation. As described above, since the molten carbonate has low ductility, not only the corrosion resistance but also the loss of electrolyte is suppressed, so that a significant improvement in battery life can be expected.
【００４５】[0045]
【発明の効果】上述のように本発明鋼は従来の溶融炭酸
塩型燃料電池用金属材料として使用されているSUS310S
鋼やSUS316L 鋼に比し、耐溶融炭酸塩腐食性に優れたス
テンレス鋼である。また、溶融炭酸塩の浸延性が小さく
電解質の損失が抑制される。As described above, the steel of the present invention is SUS310S which has been used as a conventional metal material for molten carbonate fuel cells.
Compared to steel and SUS316L steel, it is a stainless steel with excellent resistance to molten carbonate corrosion. In addition, the ductility of the molten carbonate is small, and the loss of the electrolyte is suppressed.
【００４６】更に、本発明鋼は Fe-Crからなるフェライ
ト系ステンレス鋼であることから従来使用されているFe
-Cr-Ni系ステンレス鋼より安価となる。本発明鋼は、溶
融炭酸塩型燃料電池の集電板やセパレータ板として使用
した場合、電池の寿命を大幅に向上させることが可能と
なる。Further, the steel of the present invention is a ferritic stainless steel made of Fe--Cr,
-Less expensive than Cr-Ni stainless steel. When the steel of the present invention is used as a current collector plate or a separator plate of a molten carbonate fuel cell, the life of the battery can be significantly improved.
【図１】溶融炭酸塩を試験片に塗布後、 650℃で 200時
間保持した後の腐食減量と鋼中Ti量との関係を示す図で
ある。FIG. 1 is a graph showing the relationship between the corrosion loss and the amount of Ti in steel after a molten carbonate was applied to a test piece and kept at 650 ° C. for 200 hours.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭61−161665（ＪＰ，Ａ) 特開 昭63−199858（ＪＰ，Ａ) 特開 昭62−267416（ＪＰ，Ａ) 特開 平３−2330（ＪＰ，Ａ) 特開 昭50−109809（ＪＰ，Ａ) 特開 平５−195053（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C22C 38/00 - 38/60 H01M 8/18 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-161665 (JP, A) JP-A-63-199858 (JP, A) JP-A-62-267416 (JP, A) 2330 (JP, A) JP-A-50-109809 (JP, A) JP-A-5-195053 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C22C 38/00-38 / 60 H01M 8/18
Claims (2)
Mn：1%以下、Cr：8〜19.1%、Mo： 2%以下、Ti：0.1〜3%
を含み、残部実質的にFeおよび不可避的不純物からな
ることを特徴とする溶融炭酸塩型燃料電池用フェライト
系ステンレス鋼。(1) In weight%, C: 0.08% or less, Si: 0.01 to 2%,
Mn: 1% or less, Cr: 8 to 19.1 %, Mo: 2% or less, Ti: 0.1 to 3%
Hints, balance substantially Fe and molten carbonate, characterized in that the unavoidable impurities fuel cell ferritic stainless steel.
Mn：1%以下、Cr：8〜22%、Mo：2%以下、Ti：0.1〜3%を
含有し、更にCu：0.1〜2%を含み、残部実質的にFeおよ
び不可避的不純物からなることを特徴とする溶融炭酸塩
型燃料電池用フェライト系ステンレス鋼。2. The composition according to claim 2, wherein C: 0.08% or less, Si: 0.01-2%,
Mn: 1% or less, Cr: 8 to 22%, Mo: 2% or less, Ti: 0.1 to 3%, further containing Cu: 0.1 to 2%, the balance substantially consisting of Fe and unavoidable impurities Molten carbonate characterized by the following:
Ferritic stainless steel for fuel cells .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7001281A JP3008798B2 (en) | 1995-01-09 | 1995-01-09 | Ferritic stainless steel for molten carbonate fuel cells |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7001281A JP3008798B2 (en) | 1995-01-09 | 1995-01-09 | Ferritic stainless steel for molten carbonate fuel cells |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08188853A JPH08188853A (en) | 1996-07-23 |
| JP3008798B2 true JP3008798B2 (en) | 2000-02-14 |
Family
ID=11497075
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7001281A Expired - Fee Related JP3008798B2 (en) | 1995-01-09 | 1995-01-09 | Ferritic stainless steel for molten carbonate fuel cells |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3008798B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10025108A1 (en) | 2000-05-20 | 2001-11-29 | Forschungszentrum Juelich Gmbh | High temperature material |
-
1995
- 1995-01-09 JP JP7001281A patent/JP3008798B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08188853A (en) | 1996-07-23 |
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