JPH08260110A - Sheet or thin-walled tube of ferritic stainless steel excellent in high temperature oxidation resistance and adhesion of scale - Google Patents
Sheet or thin-walled tube of ferritic stainless steel excellent in high temperature oxidation resistance and adhesion of scaleInfo
- Publication number
- JPH08260110A JPH08260110A JP9015895A JP9015895A JPH08260110A JP H08260110 A JPH08260110 A JP H08260110A JP 9015895 A JP9015895 A JP 9015895A JP 9015895 A JP9015895 A JP 9015895A JP H08260110 A JPH08260110 A JP H08260110A
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- Prior art keywords
- less
- thin
- scale
- oxidation
- high temperature
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は，特に各種内燃機関やガ
スタービン等の排ガス管路部材用途に好適な耐高温酸化
性およびスケール密着性に優れた低コストのフエライト
系ステンレス鋼の薄板または薄肉管に関する。BACKGROUND OF THE INVENTION The present invention relates to a low-cost ferrite-based stainless steel thin plate or thin plate excellent in high temperature oxidation resistance and scale adhesion, which is suitable for use in exhaust gas pipeline members such as various internal combustion engines and gas turbines. Regarding tubes.
【０００２】[0002]
【従来の技術】近年，環境問題に関する関心の高まりか
ら，燃焼効率の良い火力発電システムや機関，更には排
ガス規制をクリアできる自動車エンジンが求められてい
る。これらの要求を満足すべく対策を行なうと，燃焼ガ
スの温度が高くなり，排ガス浄化システムなどの周辺部
材の温度が高くなる。この結果，これらの部材は一層優
れた耐熱性が要求されるようになってくる。耐熱性には
高温強度に加えて高温のガス環境下で耐用できる耐高温
酸化性が必要である。2. Description of the Related Art In recent years, as interest in environmental problems has increased, thermal power generation systems and engines with good combustion efficiency, as well as automobile engines capable of meeting exhaust gas regulations have been demanded. If measures are taken to satisfy these requirements, the temperature of the combustion gas will rise, and the temperature of peripheral components such as the exhaust gas purification system will rise. As a result, these members are required to have even higher heat resistance. In addition to high-temperature strength, heat resistance requires high-temperature oxidation resistance that can withstand high-temperature gas environments.
【０００３】耐高温酸化性は，異常酸化を起こさず酸化
増量が少ないことと，酸化スケール（酸化皮膜）の密着
性が良好であることである。高Ｃｒステンレス鋼を加熱
した場合，表面には保護性の高い酸化皮膜（酸化物）が
生成する。この酸化物は加熱時間の増大にともない増加
するが，この酸化物が加熱中に何らかの理由で割れたり
剥離した場合には，雰囲気中の酸素が鋼素地に触れるた
め，酸化が加熱途中から急速に進む。この結果，表面は
厚いコブ状の酸化物に覆われ，酸化物は鋼の内部に向か
って生成するために，場合によっては酸化物が板厚方向
に貫通することがある。これを「異常酸化」と定義して
いる。The high temperature oxidation resistance is that abnormal oxidation does not occur and the amount of increased oxidation is small, and that the adhesion of the oxide scale (oxide film) is good. When high Cr stainless steel is heated, a highly protective oxide film (oxide) is formed on the surface. This oxide increases as the heating time increases, but if the oxide cracks or peels off during heating for some reason, the oxygen in the atmosphere touches the steel substrate, and oxidation rapidly starts during heating. move on. As a result, the surface is covered with a thick hump-shaped oxide, and the oxide is generated toward the inside of the steel, so that the oxide may penetrate in the plate thickness direction in some cases. This is defined as "abnormal oxidation".
【０００４】一方，スケール剥離は，加熱中に鋼の表面
に生成した酸化物が，主にその冷却途中に剥がれ落ちる
現象である。これは，鋼素地と酸化物の熱膨脹差が大き
い場合や，加熱・冷却の繰り返しを受けることによって
生じることが多い。例えば自動車のエンジンなどの内燃
機関では運転および停止の繰り返しがあり，また火力発
電システムでもＤＳＳ（毎日起動停止）操業があるため
に耐熱部材も加熱・冷却の繰り返しを受ける。従って酸
化皮膜の密着性が良くない材料は酸化皮膜が剥離し，こ
れが原因となって，配管の目づまりを起こしたり，部材
そのものの肉厚減少が起こり，そこを起点とした破損な
どの問題が生じる。On the other hand, scale peeling is a phenomenon in which oxides formed on the surface of steel during heating fall off mainly during cooling. This often occurs when there is a large difference in thermal expansion between the steel substrate and the oxide, or due to repeated heating and cooling. For example, an internal combustion engine such as an automobile engine has to be repeatedly operated and stopped, and a thermal power generation system also has a DSS (daily start / stop) operation, so that the heat resistant member is also repeatedly heated and cooled. Therefore, for materials with poor oxide film adhesion, the oxide film peels off, which causes clogging of the piping and a decrease in the wall thickness of the member itself, causing problems such as damage starting from that point. .
【０００５】オーステナイト系ステンレス鋼は，フエラ
イト系ステンレス鋼と比較して高温強度が高い。しか
し，熱膨張が大きいため，熱ひずみが大きく，加熱およ
び冷却の繰り返しを受けると熱疲労による割れを起こし
やすい。また，オーステナイト系ステンレス鋼は，鋼素
地と酸化スケールとの熱膨張の差が大きいため，酸化皮
膜の剥離も多い。Austenitic stainless steel has higher high temperature strength than ferritic stainless steel. However, since the thermal expansion is large, the thermal strain is large, and cracks due to thermal fatigue tend to occur when subjected to repeated heating and cooling. In addition, the austenitic stainless steel has a large difference in thermal expansion between the steel base and the oxide scale, so that the oxide film often peels off.
【０００６】これらの理由から，自動車の排ガス用材料
にはフエライト系ステンレス鋼が使用されている。例え
ば，自動車のエキゾーストマニホールドには，フエライ
ト系ステンレス鋼のSUS430J1Lが使用されているが，酸
化皮膜の剥離が多く, また，素材のコストが高いことが
問題視されている。そこで，SUS430J1Lと同等の高温強
度を有しながら，一層優れた耐高温酸化性，とくに酸化
皮膜の密着性に優れた特性を示す安価な材料が排ガス部
材の分野に求められるようになった。For these reasons, ferritic stainless steel is used as a material for automobile exhaust gas. For example, SUS430J1L, a ferritic stainless steel, is used in the exhaust manifold of automobiles, but the oxide film is often peeled off, and the material cost is high. Therefore, there has been a demand in the field of exhaust gas components for an inexpensive material that has the same high-temperature strength as SUS430J1L, but exhibits even better high-temperature oxidation resistance, especially the adhesion of the oxide film.
【０００７】従来のSUS430J1Lは，一般に鋳物やSUS409L
などのＣｒ量が低い材料の, 耐用温度を超える温度域,
具体的には排気ガスの温度が 900℃となるような排ガ
ス用途部材で使用される。したがって，実用上は，安全
性を考慮にいれて最高使用温度 930℃で十分な耐酸化性
を有する材料が必要となる。さらに，エキゾーストマニ
ホールド直下の触媒担体の異常燃焼を考慮した場合, 最
高使用温度は 950℃で十分な耐酸化性を有する材料が望
まれている。Conventional SUS430J1L is generally cast or SUS409L
For materials with low Cr content, such as temperature range exceeding service temperature,
Specifically, it is used in exhaust gas applications where the temperature of exhaust gas reaches 900 ℃. Therefore, for practical use, a material that has sufficient oxidation resistance at the maximum operating temperature of 930 ° C is required in consideration of safety. Furthermore, considering abnormal combustion of the catalyst carrier directly under the exhaust manifold, a material with a maximum operating temperature of 950 ° C and sufficient oxidation resistance is desired.
【０００８】以上のような背景から，本発明らは，酸化
皮膜の密着性に優れた安価なフエライト系ステンレス鋼
として，国際公開 WO-94/25636号および特開平7-11394
号公報に記載したように，900 ℃から1000℃の範囲にお
いて良好な耐高温酸化性を有する鋼を開発することがで
きた。この鋼は，酸化増量の抑制にはＳｉが，そして酸
化スケール密着性にはＭｎの添加が有効であり，両者の
適正量はＭｎ／Ｓｉ量で規定されることを示している。
そして，このような酸化物の成長およびスケール剥離の
抑制は，いずれも異常酸化の抑制に有効であり，特に最
高使用温度 930℃の場合にはＣｒ＋Ｍｎ＋Ｓｉ≧１４.
７，最高使用温度950 ℃の場合にはＣｒ＋Ｍｎ＋Ｓｉ≧
１５.５と，それぞれの合計量を厳しく規制することに
よって，異常酸化を起こさないフエライト系ステンレス
鋼が安定して得られることを明らかにした。From the above background, the present invention has been proposed as an inexpensive ferritic stainless steel excellent in the adhesion of an oxide film in WO-94 / 25636 and JP-A-7-11394.
As described in the publication, it was possible to develop a steel having good high temperature oxidation resistance in the range of 900 ° C to 1000 ° C. This steel shows that the addition of Si is effective for suppressing the increase in the amount of oxidation and the addition of Mn is effective for the oxide scale adhesion, and the appropriate amount of both is specified by the amount of Mn / Si.
In addition, such suppression of oxide growth and scale delamination is effective in suppressing abnormal oxidation, and Cr + Mn + Si ≧ 14 when the maximum operating temperature is 930 ° C.
7. Cr + Mn + Si ≥ when the maximum operating temperature is 950 ℃
It was clarified that by strictly controlling the total amount of 15.5 and each of them, ferritic stainless steel that does not cause abnormal oxidation can be stably obtained.
【０００９】[0009]
【発明が解決しようとする課題】しかし，自動車の排ガ
ス規制，その中でもコールドスタート時の規制は，ます
ます厳しくなる傾向にあり，排ガス浄化システムの構造
そのものを見直す必要が生じている。その対策の一つと
して，触媒コンバータまでの排ガス経路を薄肉の２重管
にすることが提案されている。２重管にすると，外管と
内管の間の空気が断熱層の役割を果たし，結果としてコ
ールドスタート時の排ガス温度の低下が抑制され，排ガ
ス浄化効率が上昇するからである。[Problems to be Solved by the Invention] However, exhaust gas regulations of automobiles, especially regulations at the time of cold start, tend to become more and more strict, and it is necessary to reexamine the structure itself of an exhaust gas purification system. As one of the countermeasures, it has been proposed to use a thin double tube as the exhaust gas path to the catalytic converter. This is because when the double pipe is used, the air between the outer pipe and the inner pipe acts as a heat insulating layer, and as a result, the decrease in exhaust gas temperature at cold start is suppressed and the exhaust gas purification efficiency is increased.
【００１０】このような場合にも，とくに内管側の材料
では排ガスに曝される温度自体は従来と大きくは変わら
ない。しかし，板厚が薄くなっている点で状況が異な
り，この場合には，前述の本発明者らが提案したよう鋼
において，単に成分の規定のみでは必ずしも良好な高温
耐酸化特性を維持できないことが明らかとなった。した
がって本発明の課題は，前述の本発明者らが提案したフ
エライト系ステンレス鋼において，さらに板厚が薄い場
合にも適用可能な条件を見いだすことにある。Even in such a case, the temperature itself exposed to the exhaust gas is not much different from that of the conventional material, especially for the material on the inner pipe side. However, the situation is different in that the plate thickness is thin, and in this case, in the steel as proposed by the present inventors, it is not always possible to maintain good high-temperature oxidation resistance properties simply by specifying the composition. Became clear. Therefore, an object of the present invention is to find a condition applicable to the ferrite stainless steel proposed by the present inventors even when the plate thickness is thinner.
【００１１】[0011]
【課題を解決するための手段】本発明者らは，重量％に
おいて，Ｃ：0.03％以下，Ｓi：0.80％〜1.20％,Ｍn：
0.60％〜1.50％, Ｃr：11.0％以上場合によっては13.5
％以上で15.5％以下，Ｎb：0.20％〜0.80％, Ｔi：０％
〜0.1％，Ｃu：0.02％〜0.30％未満, Ｎ：0.03％以下，
Ａl：０％〜0.05％，Ｏ：0.012％以下を含有し，且つ 0.7≦Ｍn/Ｓi≦1.5 ・・・(1) の関係を満足するようにＭｎとＳｉ量が調整され，残部
がＦｅおよび不可避的不純物からなるフエライト系ステ
ンレス鋼において，該鋼の板厚をｔ（ｍｍ）としたとき
に，この板厚ｔの鋼が大気雰囲気下において加熱温度Ｔ
（℃）で２００時間連続加熱された後の酸化増量が０.
２kg/m2 以下で且つスケール剥離量が０.０１kg/m2 以
下となる特性が次の規制によって満たされることを見出
した。[Means for Solving the Problems] The present inventors, in weight%, C: 0.03% or less, Si: 0.80% to 1.20%, Mn:
0.60% to 1.50%, Cr: 11.0% or more 13.5 in some cases
% To 15.5%, Nb: 0.20% to 0.80%, Ti: 0%
~ 0.1%, Cu: 0.02% ~ less than 0.30%, N: 0.03% or less,
Al: 0% to 0.05%, O: 0.012% or less, and the amounts of Mn and Si were adjusted so that the relationship of 0.7 ≦ Mn / Si ≦ 1.5 (1) was satisfied, and the balance Fe and In a ferritic stainless steel composed of unavoidable impurities, when the plate thickness of the steel is t (mm), the steel having the plate thickness t has a heating temperature T in an air atmosphere.
Oxidation weight gain after continuous heating at (℃) for 200 hours is 0.
And scale peeling amount 2 kg / m 2 or less characteristic to be 0.01 kg / m 2 or less were found to be satisfied by the following regulations.
【００１２】すなわち，Ｔが９３０℃のときは， Ｃｒ＋Ｓｉ＋Ｍｎ≧１４.７ ・・・(2) Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.０ ・・・(3) の(2) と(3) の関係を同時に充足し，Ｔが９５０℃のと
きは， Ｃｒ＋Ｓｉ＋Ｍｎ≧１５.５ ・・・(4) Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.５ ・・・(5) の(4) と(5) の関係を同時に充足することである。That is, when T is 930 ° C., the relation between (2) and (3) of Cr + Si + Mn ≧ 14.7 (2) Cr + Si + Mn ≧ 1.2 / t + 14.0 (3) is satisfied. At the same time, when T is 950 ℃, Cr + Si + Mn ≧ 15.5 ・ ・ ・ (4) Cr + Si + Mn ≧ 1.2 / t + 14.5 ・ ・ ・ (5) (4) and (5) should be satisfied at the same time. It is to be satisfied.
【００１３】[0013]
【作用】フエライト系ステンレス鋼においては，特公昭
59-15976号公報に記載されているように, Ｌa,Ｃe,Ｙな
どの希土類元素を含有させれば良好な高温酸化特性を示
すことがよく知られている。また特公昭57-2267 号公報
に記載されているようにＣ, ＮおよびＭnを低減し且つ
Ｓi含有量を高めることにより耐酸化性, 成形性および
溶接性を改善できることが知られている。そして特開昭
60-145359号公報に記載のように耐酸化性に有効なＡlを
Ｓiで置換して耐酸化性を保持させることが知られてい
る。しかし，耐酸化性が製品の板厚によって変化するこ
とは全く述べられていない。[Function] For ferrite stainless steel,
As described in JP-A-59-15976, it is well known that when a rare earth element such as La, Ce or Y is contained, good high temperature oxidation characteristics are exhibited. It is also known that the oxidation resistance, the formability and the weldability can be improved by reducing C, N and Mn and increasing the Si content as described in Japanese Patent Publication No. 57-2267. And JP Sho
As described in JP-A-60-145359, it is known that Al, which is effective for oxidation resistance, is replaced with Si to maintain the oxidation resistance. However, it is not mentioned at all that the oxidation resistance changes depending on the thickness of the product.
【００１４】本発明者らは，板厚と高温耐酸化性との関
係を見いだすべく，種々の試験を重ねたが，前記のフエ
ライト系ステンレス鋼において，(1) 式を満たしたう
え，加熱温度Ｔとの関係において，(2) と(3) 式または
(4) と(5) 式を同時に満足することが，酸化増量の抑制
とスケール密着性という高温耐酸化特性を発現するうえ
で必要なことを知った。すなわち，これらの式に従っ
て，製品の最高使用温度に応じて製品の板厚と合金元素
を厳密に規制することが肝要である。以下にその詳細を
説明する。The inventors of the present invention conducted various tests in order to find the relationship between the plate thickness and the high temperature oxidation resistance. In the above-mentioned ferrite stainless steel, the formula (1) was satisfied and the heating temperature was changed. In relation to T, equations (2) and (3) or
We have found that satisfying Eqs. (4) and (5) at the same time is necessary in order to suppress the increase in oxidation and develop the high-temperature oxidation resistance properties of scale adhesion. That is, it is important to strictly control the plate thickness and alloy elements of the product according to the maximum operating temperature of the product according to these equations. The details will be described below.
【００１５】図１は，フエライト系ステンレス鋼におけ
る各成分量はそれぞれ本発明で規定する範囲内で且つ
(1) 式を満足したＳｉ量とＭｎ量としたうえで，鋼中の
（Ｃｒ＋Ｍｎ＋Ｓｉ）の量を板厚毎に種々変化させ，こ
れらの鋼を９５０℃で大気中２００時間の連続加熱試験
を行ったときの酸化増量を測定し，その結果を，板厚と
（Ｃｒ＋Ｍｎ＋Ｓｉ）量で整理したものである。FIG. 1 shows that the amounts of the respective components in the ferrite stainless steel are within the ranges specified in the present invention.
After the amount of Si and Mn satisfying the formula (1) is set, the amount of (Cr + Mn + Si) in the steel is changed variously for each plate thickness, and these steels are subjected to a continuous heating test at 950 ° C. in the atmosphere for 200 hours. The amount of increase in oxidation when measured was measured, and the result was arranged by the plate thickness and the amount of (Cr + Mn + Si).
【００１６】図中のプロットについては，各鋼について
１０個の試験片（ｎ＝１０）について試験し，○印は全
ての試験片１０個に異常酸化が認められなかったもの，
×印は少なくとも１個の試験片に異常酸化が生じたもの
を示している。また，異常酸化を起こすと先述のように
酸化増量が急激に上昇するので，酸化増量の値としては
０.２kg/m2 以上を異常酸化の指標としている。なお，
各鋼は(1) 式のＭｎ／Ｓｉ比を０.７〜１.５に調整して
いるので，いずれもスケール剥離量は０.０１kg/m2 以
下である。Regarding the plots in the figure, 10 test pieces (n = 10) were tested for each steel, and ○ marks indicate that no abnormal oxidation was found in all 10 test pieces,
The mark x indicates that at least one test piece had abnormal oxidation. Further, as the abnormal oxidation causes the increase in the oxidation amount to increase rapidly as described above, the value of the increase in the oxidation amount is set to 0.2 kg / m 2 or more as an index of the abnormal oxidation. In addition,
Since the Mn / Si ratio of the formula (1) is adjusted to 0.7 to 1.5 for each steel, the scale peeling amount is 0.01 kg / m 2 or less in each case.
【００１７】図１の結果に見られるように，異常酸化の
有無を決定する因子は（Ｃｒ＋Ｍｎ＋Ｓｉ）と板厚であ
ることがわかる。すなわち， (1) Ｃｒ＋Ｍｎ＋Ｓｉ＜１５.５の領域では，異常酸化
はいずれの板厚でも発生している。このことから，最高
使用温度が９５０℃の場合には，少なくとも Ｃｒ＋Ｍｎ＋Ｓｉ≧１５.５ ・・(4) の関係を満足することが必要である。 (2) （Ｃｒ＋Ｍｎ＋Ｓｉ）量が高い領域（ここでは１
７.５以上）においては，板厚に依存せず異常酸化は発
生しない。 (3) （Ｃｒ＋Ｍｎ＋Ｓｉ）が(1) と(2) の間の領域すな
わち１５.５以上１７.５未満の領域では，異常酸化の有
無は板厚によって決定される。すなわち，この領域にお
いて異常酸化を起こさないためには， Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.５ ・・・(5) の関係を満足することが必要である。As can be seen from the results of FIG. 1, the factors that determine the presence or absence of abnormal oxidation are (Cr + Mn + Si) and the plate thickness. That is, (1) In the region of Cr + Mn + Si <15.5, abnormal oxidation occurs at any plate thickness. From this, it is necessary to satisfy at least the relationship of Cr + Mn + Si ≧ 15.5 ··· (4) when the maximum operating temperature is 950 ° C. (2) Region where the amount of (Cr + Mn + Si) is high (here, 1
7.5), abnormal oxidation does not occur regardless of the plate thickness. (3) In the region where (Cr + Mn + Si) is between (1) and (2), that is, in the region of 15.5 or more and less than 17.5, the presence or absence of abnormal oxidation is determined by the plate thickness. That is, in order to prevent abnormal oxidation in this region, it is necessary to satisfy the relationship of Cr + Si + Mn ≧ 1.2 / t + 14.5 (5).
【００１８】これらの理由については，必ずしも明確で
はないが，保護性の強いＣｒ酸化物は，Ｃｒが酸化スケ
ール中を外方拡散することにより進行すること，またＣ
ｒが十分に拡散できず，このためにＣｒ酸化物を生成し
ないとＦｅの酸化スケールが生成して異常酸化を起こす
ことから，(1) の領域では母相中のＣｒが酸化スケール
界面まで十分に補給されなかったことがその原因であろ
うと考えられる。Although the reasons for these are not clear, Cr oxide, which has a strong protective property, progresses due to outward diffusion of Cr in the oxide scale, and C
In the region of (1), the Cr in the matrix is not sufficiently diffused to the oxide scale interface because r cannot diffuse sufficiently, and therefore, if Cr oxide is not generated, Fe oxide scale is generated and abnormal oxidation occurs. It is thought that the cause may be that they were not replenished.
【００１９】また(2) の領域では，母相中のＣｒが酸化
スケール界面まで十分に補給されなかったことによると
考えられる。In the region (2), it is considered that Cr in the mother phase was not sufficiently supplied to the oxide scale interface.
【００２０】さらに，(3) の領域において，薄板材のみ
に異常酸化を起こしたのは，薄板材は表面積に対して体
積が小さいので，加熱初期に母相中のＣｒ濃度が減少
し，加熱中に(1) の領域のような状態になったものと考
えられる。すなわち，(3) の領域における異常酸化の有
無は，母相中に必要なＣｒ濃度が，母相の体積に対する
表面積の比，つまり板厚によって規定されること，によ
ると考えられる。Further, in the region (3), the abnormal oxidation occurs only in the thin plate material because the thin plate material has a small volume with respect to the surface area, so that the Cr concentration in the matrix decreases at the beginning of heating and It is considered that the state of (1) was reached. That is, it is considered that the presence or absence of abnormal oxidation in the region (3) is due to the fact that the Cr concentration required in the matrix is defined by the ratio of the surface area to the volume of the matrix, that is, the plate thickness.
【００２１】図２は，加熱温度を９３０℃とした以外
は，図１と同様の試験を行った結果を図１と同様の方法
で示したものである。図２の結果は，９３０℃でも異常
酸化の有無を決定する因子は（Ｃｒ＋Ｍｎ＋Ｓｉ）と板
厚であることを示している。FIG. 2 shows the results of the same tests as in FIG. 1 except that the heating temperature was 930 ° C., in the same manner as in FIG. The results in FIG. 2 indicate that the factors that determine the presence or absence of abnormal oxidation even at 930 ° C. are (Cr + Mn + Si) and the plate thickness.
【００２２】すなわち，加熱温度９３０℃では， Ｃｒ＋Ｓｉ＋Ｍｎ≧１４.７ ・・・(2) Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.０ ・・・(3) の関係を同時に満足すれば，異常酸化を生じないことが
わかる。That is, at the heating temperature of 930 ° C., if the relationship of Cr + Si + Mn ≧ 14.7 (2) Cr + Si + Mn ≧ 1.2 / t + 14.0 (3) is satisfied at the same time, abnormal oxidation does not occur. I understand.
【００２３】このように，製品の使用最高温度におい
て，製品の板厚が決まれば，異常酸化を起こさない最低
限の（Ｃｒ＋Ｍｎ＋Ｓｉ）を決定することができ，これ
によって，安定して高温耐酸化性に優れるフエライト系
ステンレス鋼の薄板または薄肉管が得られる。As described above, if the plate thickness of the product is determined at the maximum temperature of use of the product, the minimum (Cr + Mn + Si) that does not cause abnormal oxidation can be determined, whereby stable high-temperature oxidation resistance can be obtained. It is possible to obtain a thin plate or thin-walled tube of ferrite stainless steel, which is excellent in
【００２４】以下に, 本発明鋼における各成分の作用と
それらの含有量 (質量％) の限定理由を個別に概説す
る。The action of each component in the steel of the present invention and the reasons for limiting the content (mass%) of each component will be individually described below.
【００２５】ＣとＮ：ＣとＮは一般的には高温強度を高
めるためには重要な元素であるが，反面, 含有量が多く
なると耐酸化性, 加工性ならびに靭性の低下を来す。ま
た，ＣとＮはＮbとの化合物をつくり, フエライト相中
の有効Ｎb量を減少せしめる。このような理由からＣと
Ｎはそれぞれ0.03％以下とする。C and N: C and N are generally important elements for increasing the high temperature strength, but on the other hand, when the content is large, the oxidation resistance, workability and toughness deteriorate. Also, C and N form a compound with Nb, which reduces the amount of effective Nb in the ferrite phase. For these reasons, C and N are each 0.03% or less.
【００２６】Ｓi：Ｓiは耐高温酸化性を改善するために
不可欠な元素である。本発明鋼のような比較的Ｃr量が
少ない鋼であっても優れた耐高温酸化性を付与するのに
非常に有効である。しかし，過剰に添加すると硬質にな
り，加工性および靭性の劣化をもたらすので，0.8％〜
1.2％の範囲とする。Si: Si is an essential element for improving the high temperature oxidation resistance. Even a steel having a relatively small amount of Cr, such as the steel of the present invention, is very effective in imparting excellent high temperature oxidation resistance. However, if added excessively, it becomes hard and the workability and toughness are deteriorated.
The range is 1.2%.
【００２７】Ｍn：Ｍnも本発明鋼の重要な元素である。
本発明鋼のようにＳiを添加することによって，酸化増
量は抑制されるが，生成した酸化物は加熱後の冷却中に
剥離しやすくなる。Ｍnを添加するとスピネル型酸化物
を形成して表層酸化物の密着性を著しく改善する。しか
し，過剰に添加すると，オーステナイト相の析出などに
よってかえって異常酸化を誘発する。このためその範囲
を0.60％〜1.50％とする。特にＭｎ量は１.００〜１.２
０％の範囲とすることが好ましい。Mn: Mn is also an important element of the steel of the present invention.
The addition of Si as in the steel of the present invention suppresses the increase in the amount of oxidation, but the produced oxide is easily separated during cooling after heating. When Mn is added, a spinel type oxide is formed and the adhesion of the surface layer oxide is remarkably improved. However, if added excessively, abnormal oxidation is rather induced by precipitation of austenite phase. Therefore, the range is set to 0.60% to 1.50%. Especially, the Mn amount is from 1.0 to 1.2.
It is preferably in the range of 0%.
【００２８】Ｃr：Ｃrは耐高温酸化性を付与するために
は非常に有効な元素であり，耐高温酸化性を維持するた
めには11％以上の添加を必要とする。一方, 過剰に添加
すると鋼の脆化を招き，また硬質となって加工性を劣化
させる他, 原料価格が高くなる。したがって，Ｃrの範
囲は11.0％〜15.0％, 好ましくは13.5％を越え15.5％以
下とする。とくに，エキゾーストマニホールド用途にお
いて，950℃で200時間連続加熱後の酸化増量が0.2kg/m2
以下で且つスケール剥離量が0.01kg/m2以下の要求を満
たすには，Ｍn/Ｓi比がほぼ１となり且つＭnとＳiをい
ずれも約 1.0％で含有させたうえ，Ｓi＋Ｍn＋Ｃrの合
計含有量が15.5以上となるようにすることが望ましい
が，この場合にはＣr量は必然的に13.5％を越えて含有
させることが必要となる。Cr: Cr is a very effective element for imparting high temperature oxidation resistance, and 11% or more must be added to maintain high temperature oxidation resistance. On the other hand, if it is added in excess, it causes the steel to become brittle, becomes hard and deteriorates the workability, and the raw material cost increases. Therefore, the range of Cr is 11.0% to 15.0%, preferably more than 13.5% and not more than 15.5%. Especially for exhaust manifold applications, the oxidation gain after continuous heating at 950 ° C for 200 hours is 0.2 kg / m 2
In order to satisfy the requirement that the scale peeling amount is 0.01 kg / m 2 or less, the Mn / Si ratio should be approximately 1 and both Mn and Si should be contained at about 1.0%, and the total content of Si + Mn + Cr should be It is desirable that the Cr content be 15.5 or more. However, in this case, the Cr content must necessarily be more than 13.5%.
【００２９】Ｎb：Ｎbは高温強度を維持せしめるのに有
効に作用するので本発明鋼の重要な元素である。高温強
度を維持するためには少なくとも0.20％以上添加する必
要がある。一方, Ｎbを過剰に添加すると溶接高温割れ
感受性が高くなる。十分な高温強度を維持し，かつ溶接
高温割れ感受性に余り影響を及ぼさないようにＮbの上
限を0.80％とする。Nb: Nb is an important element of the steel of the present invention because it effectively acts to maintain high temperature strength. In order to maintain high temperature strength, it is necessary to add at least 0.20% or more. On the other hand, if Nb is added excessively, the hot susceptibility to welding becomes more susceptible. The upper limit of Nb is 0.80% so that sufficient high temperature strength is maintained and welding susceptibility to hot cracking is not significantly affected.
【００３０】Ｃｕ：Ｃｕは低温靱性と加工性の両方を向
上させるのに重要な元素である。しかし，過剰に添加す
るとこれらの特性を劣化させるため，Ｃｕの含有範囲は
０.０２％以上０.３０％未満とした。Cu: Cu is an important element for improving both low temperature toughness and workability. However, if added excessively, these characteristics deteriorate, so the Cu content range was made 0.02% or more and less than 0.30%.
【００３１】Ａｌ：製鋼工程において酸素吹錬により脱
炭を行うが，そのさいに鋼中に残存した酸素が鋼の溶接
性を劣化させ，造管条件が悪くなる。このため，一般に
Ａｌは脱酸材として必要不可欠な元素である。しかし，
製鋼工程においてＡｌが過剰に混入すると，溶接時にＡ
ｌ系の酸化物が多量に生成し，逆に溶接性を低下させ
る。そこで，溶接性に悪影響を及ぼさぬようＡｌの含有
量は０.０５％以下とする。なお本発明鋼はＳiを含有し
ているため，Ａlによる脱酸は必ずしも必要としない。
したがって，Ａｌ無添加でもよい。Al: Decarburization is carried out by oxygen blowing in the steelmaking process, but the oxygen remaining in the steel at that time deteriorates the weldability of the steel and deteriorates the pipe forming conditions. Therefore, in general, Al is an essential element as a deoxidizer. However,
If Al is mixed excessively in the steelmaking process, A
A large amount of 1-based oxide is generated, which conversely reduces weldability. Therefore, the Al content is set to 0.05% or less so as not to adversely affect the weldability. Since the steel of the present invention contains Si, deoxidation with Al is not always necessary.
Therefore, Al may not be added.
【００３２】Ｔi：Ｔiは鋼板のｒ値を向上させ，深絞り
性に有効に作用する。しかし，Ｔiを添加するとＴiＮを
生成しやすく，鋼板におけるヘゲ疵の発生による歩留り
の低下を来し，また溶接性も低下させる。そこで，Ｔｉ
の含有量は０％〜０.１０％とした。さらに，高周波造
管や現場施工で溶接を行ったあとに厳しい加工が施され
る場合には，ＴｉＮの生成を防止するために０〜０.０
５％とするのが好ましい。なお，０％とは無添加を意味
する。Ti: Ti improves the r value of the steel sheet and effectively acts on the deep drawability. However, when Ti is added, TiN is likely to be generated, resulting in a decrease in yield due to the occurrence of bald defects in the steel sheet, and a decrease in weldability. So Ti
Content was 0% to 0.10%. Furthermore, when severe processing is performed after welding is performed in high-frequency pipe forming or on-site construction, 0 to 0.0 is used to prevent the generation of TiN.
It is preferably 5%. In addition, 0% means no addition.
【００３３】Ｏ：Ｏは前述のように溶接性に悪影響を及
ぼすので, できる限り低いことが好ましいが，低く抑え
るほど製造コストの上昇を招く。本発明鋼においては，
ＯはＡlまたはＳiによって低減でき, またＡｌ含有量は
十分な溶接性が確保できる範囲に定めている。そこでＯ
の含有量は０.０１２％以下とした。Since O: O adversely affects the weldability as described above, it is preferable that it be as low as possible, but the lower it is, the higher the manufacturing cost will be. In the steel of the present invention,
O can be reduced by Al or Si, and the Al content is set within a range that ensures sufficient weldability. There O
Content of 0.012% or less.
【００３４】以上のような各成分の含有量において， 0.7≦Ｍn/Ｓi≦1.5 ・・(1) の関係が満足するようにＭn量とＳi量を規制することが
異常酸化およびスケール剥離を抑制するうえで重要であ
り，この(1) 式の条件を満足すれば，従来のSUS430J1L
と比較して耐高温酸化特性, とくにスケール密着性に優
れたフエライト系ステンレス鋼が得られる。In the content of each component as described above, it is possible to suppress abnormal oxidation and scale peeling by controlling the Mn amount and the Si amount so that the relationship of 0.7 ≦ Mn / Si ≦ 1.5 (1) is satisfied. It is important for the SUS430J1L to meet the requirements of Eq. (1).
Compared with the above, ferritic stainless steel having excellent high temperature oxidation resistance, especially scale adhesion, can be obtained.
【００３５】さらに，優れた耐高温酸化性を得るために
は（Ｃｒ＋Ｍｎ＋Ｓｉ）量の厳密な調整が必要であり，
最高使用温度が９３０℃では Ｃｒ＋Ｓｉ＋Ｍｎ≧１４.７ ・・・(2) の関係を満たすことが，そして，最高使用温度が９３０
℃では Ｃｒ＋Ｓｉ＋Ｍｎ≧１５.５ ・・・(4) の関係を満たすことが必要であり，これらの関係を満足
しない場合には，たとえ板厚が２.０ｍｍ以上であって
も，異常酸化を抑制できない。Further, in order to obtain excellent high temperature oxidation resistance, it is necessary to strictly adjust the amount of (Cr + Mn + Si),
When the maximum operating temperature is 930 ° C., the relationship of Cr + Si + Mn ≧ 14.7 (2) is satisfied, and the maximum operating temperature is 930.
It is necessary to satisfy the relationship of Cr + Si + Mn ≧ 15.5 (4) at ℃. If these relationships are not satisfied, abnormal oxidation is suppressed even if the plate thickness is 2.0 mm or more. Can not.
【００３６】また，酸化特性に及ぼす板厚の影響が大き
い領域では，前記図１および図２で説明したように，最
高使用温度が９３０℃では， Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.０ ・・・(3) また最高使用温度が９５０℃では Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.５ ・・・(5) の関係を満足する必要がある。なお，最高使用温度が９
１０℃以下では本発明鋼はいずれの板厚でも異常酸化を
起こさない。Further, in the region where the influence of the plate thickness on the oxidation characteristics is large, as described in FIGS. 1 and 2, when the maximum operating temperature is 930 ° C., Cr + Si + Mn ≧ 1.2 / t + 14.0 ... (3) When the maximum operating temperature is 950 ° C., it is necessary to satisfy the relationship of Cr + Si + Mn ≧ 1.2 / t + 14.5 (5). The maximum operating temperature is 9
Below 10 ° C, the steel of the present invention does not cause abnormal oxidation at any plate thickness.
【００３７】以上のように各成分をバランスさせた本発
明のフエライト系ステンレス鋼は，優れた耐高温酸化特
性とスケール密着性を有し，しかも最高使用温度および
製品の板厚ごとに使用可能な成分範囲を規定したもので
あるから，用途に応じて安定した耐高温酸化性を発揮す
ることができる，したがって，排ガス温度が一層高温化
し且つ板厚が薄くなる箇所の排ガス管路部材として非常
に有用である。The ferrite stainless steel of the present invention in which the respective components are balanced as described above has excellent high temperature oxidation resistance and scale adhesion, and can be used depending on the maximum operating temperature and the plate thickness of the product. Since the composition range is specified, stable high temperature oxidation resistance can be exhibited depending on the application, and therefore, it is extremely useful as an exhaust gas pipe member at a place where the exhaust gas temperature becomes higher and the plate thickness becomes thinner. It is useful.
【００３８】一般に，排ガス管路部材は溶接部を有する
が，本発明鋼は，溶接部の熱疲労特性も良好である。し
たがって，例えば自動車エンジンに直結するエキゾース
トマニホールドやフロントパイプ用途に適用された場合
にも十分な耐用を示す。Generally, the exhaust gas pipeline member has a welded portion, but the steel of the present invention also has good thermal fatigue properties at the welded portion. Therefore, even when it is applied to an exhaust manifold directly connected to an automobile engine or a front pipe, it has sufficient durability.
【００３９】エキゾーストマニホールドもしくはフロン
トパイプは，予め高周波溶接によって造管したパイプ
を, さらに必要な形状寸法に加工および溶接して製造さ
れ, 使用にあたっては振動および高温の排ガスに曝さ
れ, しかも加熱冷却の繰り返しを受けるが，これらの部
材に使用された本発明鋼は溶接部を有していても熱疲労
特性に優れ且つ酸化増量が少なくスケール密着性にも優
れるので，従来材よりも安価にして且つ十分な耐用を示
す。The exhaust manifold or the front pipe is manufactured by processing and welding a pipe manufactured by high-frequency welding in advance into a required shape and dimension. When used, it is exposed to vibration and high-temperature exhaust gas, and is repeatedly heated and cooled. However, since the steel of the present invention used for these members has excellent thermal fatigue properties even with a welded portion, little increase in oxidation and excellent scale adhesion, it is cheaper than conventional materials and sufficient. Shows a long life.
【００４０】エキゾーストマニホールドもしくはフロン
トパイプに限らず，本発明の低コストフエライト系ステ
ンレス鋼は９００〜９５０℃の高温で使用され且つ耐高
温酸化性およびスケール密着性が重要視される部材例え
ば火力発電システムの排ガス経路用部材等にも好適に使
用できる。Not limited to the exhaust manifold or the front pipe, the low-cost ferrite stainless steel of the present invention is used at a high temperature of 900 to 950 ° C. and is a member for which high temperature oxidation resistance and scale adhesion are important, such as a thermal power generation system. It can also be suitably used as a member for an exhaust gas passage.
【００４１】[0041]
【実施例】表１に供試材の化学成分値（重量％）を示し
た。これらの鋼はいずれも溶製，鍛造, 熱延により厚さ
4.5mmの熱延鋼帯とした。これを1050℃で焼鈍し，種々
の板厚の冷延鋼帯としたのち，1050℃で焼鈍し，試験片
に加工後, 高温酸化試験に供した。[Examples] Table 1 shows the chemical component values (% by weight) of the test materials. All of these steels are thickened by melting, forging and hot rolling.
A 4.5 mm hot rolled steel strip was used. This was annealed at 1050 ° C to make cold-rolled steel strips with various thicknesses, then annealed at 1050 ° C, processed into a test piece, and subjected to a high-temperature oxidation test.
【００４２】高温酸化試験は，長さ３５ｍｍ，幅２５ｍ
ｍで種々の板厚をもつ試験片を大気中で９３０℃または
９５０℃で２００時間連続加熱し，加熱後の単位面積当
りの酸化増量を求め，酸化増量が０.２kg/m2 を超えた
試験片を異常酸化が発生したものとした。試験は，各鋼
の各板厚毎にそれぞれ１０個の試験片（ｎ＝１０）を同
一条件下での高温酸化試験を行い，その結果を表２に示
した。表２において，○印は１０個の試験片全てに異常
酸化を発生しなかったもの，×印はその少なくとも１個
に異常酸化を発生したものを示す。The high temperature oxidation test was conducted with a length of 35 mm and a width of 25 m.
Specimens with various thicknesses in m were continuously heated in air at 930 ° C or 950 ° C for 200 hours, and the oxidative weight increase per unit area after heating was determined. The oxidative weight gain exceeded 0.2 kg / m 2 . The test piece was determined to have abnormal oxidation. In the test, 10 test pieces (n = 10) for each plate thickness of each steel were subjected to a high temperature oxidation test under the same conditions, and the results are shown in Table 2. In Table 2, ∘ indicates that all 10 test pieces did not undergo abnormal oxidation, and x indicates that at least one of them did not undergo abnormal oxidation.
【００４３】[0043]
【表１】 [Table 1]
【００４４】[0044]
【表２】 [Table 2]
【００４５】[0045]
【発明の効果】以上説明したように, 本発明によれば,
Ｃr量が比較的低いフエライト系ステンレス鋼にあっ
て，９００〜９５０℃の高温で使用されかつ高温酸化特
性およびスケール剥離量が重要視される排ガス管路部材
として十分に耐用できる安価な材料が提供され，特に自
動車エンジンのエキゾーストマニホールドやフロントパ
イプを構成する材料あるいは火力発電システムの高温排
ガス管路部材を構成する材料として，板厚が異なって
も，その板厚に応じて耐高温酸化性が安定して保持され
るようになったので，この分野の技術向上に大きく貢献
できる。As described above, according to the present invention,
An inexpensive material that can be sufficiently used as an exhaust gas pipe member that is used at a high temperature of 900 to 950 ° C. and has a high temperature oxidation property and the amount of scale peeling is important in a ferrite stainless steel with a relatively low Cr content. In particular, as a material forming the exhaust manifold or front pipe of an automobile engine or a material forming the high temperature exhaust gas pipe member of a thermal power generation system, even if the plate thickness is different, the high temperature oxidation resistance is stable depending on the plate thickness. Since it has been maintained as a result, it can greatly contribute to technological improvement in this field.
【図１】９５０℃×２００時間の大気中連続加熱したと
きの酸化特性に及ぼす（Ｃｒ＋Ｍｎ＋Ｓｉ）量と板厚の
関係を示す図である。FIG. 1 is a diagram showing the relationship between the amount of (Cr + Mn + Si) and the plate thickness that affect the oxidation characteristics when continuously heated in the air at 950 ° C. for 200 hours.
【図２】９３０℃×２００時間の大気中連続加熱したと
きの酸化特性に及ぼす（Ｃｒ＋Ｍｎ＋Ｓｉ）量と板厚の
関係を示す図である。FIG. 2 is a diagram showing the relationship between the amount of (Cr + Mn + Si) and the plate thickness that affect the oxidation characteristics when continuously heated in the air at 930 ° C. for 200 hours.
Claims (5)
i：0.80％〜1.20％,Ｍn：0.60％〜1.50％,Ｃr：11.0％
〜15.5％,Ｎb：0.20％〜0.80％,Ｔi：０％〜0.1％，Ｃ
u：0.02％〜0.30％未満,Ｎ：0.03％以下，Ａl：０％〜
0.05％，Ｏ：0.012％以下,を含有し，且つ 0.7≦Ｍn/Ｓi≦1.5 ・・・(1) Ｃｒ＋Ｓｉ＋Ｍｎ≧１４.７ ・・・(2) の関係，並びに板厚をｔ（ｍｍ）としたときに， Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.０ ・・・(3) の関係(1),(2) および(3) を同時に満足するようにＳ
ｉ, ＭｎおよびＣｒ量が調整され，残部がＦeおよび不
可避的不純物からなり，大気雰囲気下 930℃で 200時間
連続加熱後の酸化増量が 0.2 kg/m2以下でスケール剥離
量が 0.01kg/m2以下である耐高温酸化性およびスケール
密着性に優れたフエライト系ステンレス鋼の薄板または
薄肉管。1. C: 0.03% or less, S in mass%
i: 0.80% to 1.20%, Mn: 0.60% to 1.50%, Cr: 11.0%
~ 15.5%, Nb: 0.20% ~ 0.80%, Ti: 0% ~ 0.1%, C
u: 0.02% to less than 0.30%, N: 0.03% or less, Al: 0% to
0.05%, O: 0.012% or less, and 0.7 ≦ Mn / Si ≦ 1.5 (1) Cr + Si + Mn ≧ 14.7 (2) and the plate thickness is t (mm) In order to satisfy the relations (1), (2) and (3) of Cr + Si + Mn ≧ 1.2 / t + 14.0 (3) at the same time,
The amount of i, Mn, and Cr was adjusted, and the balance consisted of Fe and unavoidable impurities. The oxidation increase after continuous heating for 200 hours at 930 ° C in the air atmosphere was 0.2 kg / m 2 or less, and the scale peeling amount was 0.01 kg / m 2. Thin plate or thin-walled tube of ferritic stainless steel with excellent high temperature oxidation resistance and scale adhesion of 2 or less.
0.80％〜1.20％,Ｍn：0.60％〜1.50％,Ｃr：13.5％を越
え〜15.5％,Ｎb：0.20％〜0.80％,Ｔi：０％〜0.1％，
Ｃu：0.02％〜0.30％未満,Ｎ：0.03％以下,Ａl：０％〜
0.05％以下，Ｏ：0.012％以下,を含有し，且つ 0.7≦Ｍn/Ｓi≦1.5 ・・・(1) Ｃｒ＋Ｓｉ＋Ｍｎ≧１５.５ ・・・(4) の関係，並びに板厚をｔ（ｍｍ）としたときに， Ｃｒ＋Ｓｉ＋Ｍｎ≧１.２／ｔ＋１４.５ ・・・(5) の関係(1),(4) および(5) を同時に満足するようにＳ
ｉ，ＭｎおよびＣｒ量が調整され，残部がＦeおよび不
可避的不純物からなり，大気雰囲気下 950℃で 200時間
連続加熱後の酸化増量が0.2kg/m2以下でスケール剥離量
が 0.01kg/m2以下である耐高温酸化性およびスケール密
着性に優れたフエライト系ステンレス鋼の薄板または薄
肉管。2. In mass%, C: 0.03% or less, Si:
0.80% ~ 1.20%, Mn: 0.60% ~ 1.50%, Cr: over 13.5% ~ 15.5%, Nb: 0.20% ~ 0.80%, Ti: 0% ~ 0.1%,
Cu: 0.02% to less than 0.30%, N: 0.03% or less, Al: 0% to
0.05% or less, O: 0.012% or less, and 0.7 ≦ Mn / Si ≦ 1.5 (1) Cr + Si + Mn ≧ 15.5 (4) and the plate thickness t (mm) , Cr + Si + Mn ≧ 1.2 / t + 14.5 ・ ・ ・ S5 so that the relations (1), (4) and (5) of (5) are satisfied at the same time.
The amount of i, Mn and Cr is adjusted, the balance consists of Fe and unavoidable impurities, and the oxidation increase after continuous heating for 200 hours at 950 ℃ in air atmosphere is 0.2kg / m 2 or less and the scale peeling amount is 0.01kg / m. Thin plate or thin-walled tube of ferritic stainless steel with excellent high temperature oxidation resistance and scale adhesion of 2 or less.
部材に加工されている請求項１または２に記載の薄板ま
たは薄肉管。3. The thin plate or thin-walled pipe according to claim 1, wherein the steel is processed into a member forming an exhaust gas pipe of an internal combustion engine.
は，自動車エンジンに接続されたエキゾーストマニホー
ルドまたはフロントパイプである請求項３に記載の薄板
または薄肉管。4. The thin plate or thin-walled pipe according to claim 3, wherein the member constituting the exhaust gas pipe line of the internal combustion engine is an exhaust manifold or a front pipe connected to an automobile engine.
３または４に記載の薄板または薄肉管。5. The plate thickness of 2 mm or less,
The thin plate or thin-walled tube according to 3 or 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9015895A JPH08260110A (en) | 1995-03-23 | 1995-03-23 | Sheet or thin-walled tube of ferritic stainless steel excellent in high temperature oxidation resistance and adhesion of scale |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9015895A JPH08260110A (en) | 1995-03-23 | 1995-03-23 | Sheet or thin-walled tube of ferritic stainless steel excellent in high temperature oxidation resistance and adhesion of scale |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08260110A true JPH08260110A (en) | 1996-10-08 |
Family
ID=13990693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9015895A Pending JPH08260110A (en) | 1995-03-23 | 1995-03-23 | Sheet or thin-walled tube of ferritic stainless steel excellent in high temperature oxidation resistance and adhesion of scale |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08260110A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1408132A1 (en) * | 2002-10-08 | 2004-04-14 | Nisshin Steel Co., Ltd. | Ferritic stainless steel sheet for use in exhaust parts with good formability, high-temperature strength, high-temperature oxidation resistance, and low-temperature toughness |
| WO2007067134A1 (en) * | 2005-10-17 | 2007-06-14 | Sandvik Intellectual Property Ab | Tube |
| EP2264202A1 (en) * | 2008-03-07 | 2010-12-22 | JFE Steel Corporation | Ferritic stainless steel with excellent heat resistance and toughness |
| EP2639325A4 (en) * | 2010-11-11 | 2016-08-17 | Jfe Steel Corp | Ferritic stainless steel with excellent oxidation resistance |
-
1995
- 1995-03-23 JP JP9015895A patent/JPH08260110A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1408132A1 (en) * | 2002-10-08 | 2004-04-14 | Nisshin Steel Co., Ltd. | Ferritic stainless steel sheet for use in exhaust parts with good formability, high-temperature strength, high-temperature oxidation resistance, and low-temperature toughness |
| WO2007067134A1 (en) * | 2005-10-17 | 2007-06-14 | Sandvik Intellectual Property Ab | Tube |
| EP2264202A1 (en) * | 2008-03-07 | 2010-12-22 | JFE Steel Corporation | Ferritic stainless steel with excellent heat resistance and toughness |
| EP2264202A4 (en) * | 2008-03-07 | 2013-12-25 | Jfe Steel Corp | Ferritic stainless steel with excellent heat resistance and toughness |
| EP2639325A4 (en) * | 2010-11-11 | 2016-08-17 | Jfe Steel Corp | Ferritic stainless steel with excellent oxidation resistance |
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