JPH07331390A - High chromium austenitic heat resistant alloy - Google Patents
High chromium austenitic heat resistant alloyInfo
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- JPH07331390A JPH07331390A JP12640794A JP12640794A JPH07331390A JP H07331390 A JPH07331390 A JP H07331390A JP 12640794 A JP12640794 A JP 12640794A JP 12640794 A JP12640794 A JP 12640794A JP H07331390 A JPH07331390 A JP H07331390A
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- corrosion resistance
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ボイラや化学プラント
等の苛酷な高温腐食環境下においても、高温強度と耐食
性に優れる高クロムオーステナイト耐熱合金に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high chromium austenite heat resistant alloy which is excellent in high temperature strength and corrosion resistance even in a severe high temperature corrosive environment such as a boiler or a chemical plant.
【０００２】[0002]
【従来の技術】近年、火力発電プラントにおいては熱効
率の改善を目的とする超高温高圧ボイラが注目されてい
る。このボイラでは、従来のボイラと比較して蒸気条件
が高温化、高圧化されているため、過熱器管材料として
は高温強度や耐食性に対する一段と厳しい要求性能が満
たされなければならない。このため、従来多く使用され
ている18−８系ステンレス鋼より高い高温強度を有し、
かつ耐水蒸気酸化特性や耐高温腐食特性にも優れる高強
度高耐食オーステナイト鋼が要求される。2. Description of the Related Art In recent years, ultra-high temperature and high pressure boilers for the purpose of improving thermal efficiency have been attracting attention in thermal power plants. In this boiler, the steam conditions are higher in temperature and higher in pressure than conventional boilers, and therefore the superheater tube material must meet even more severe performance requirements for high temperature strength and corrosion resistance. Therefore, it has higher high-temperature strength than 18-8 series stainless steel that has been widely used,
In addition, high-strength, high-corrosion-resistant austenitic steel that is also excellent in steam oxidation resistance and high-temperature corrosion resistance is required.
【０００３】一般に、耐食性を改善するためには、鋼中
のCr含有量を高めることが有効である。しかし、例えば
25％程度のCrを含有するＳＵＳ310 STB 鋼にみられるよ
うに、 600〜700 ℃での高温強度は18−８系ステンレス
鋼よりむしろ低めであり、かつσ相析出による靱性劣化
の問題がある。さらに、25％程度のCr含有量では厳しい
腐食環境下では耐食性が十分でない。Generally, in order to improve the corrosion resistance, it is effective to increase the Cr content in steel. But for example
As seen in SUS310 STB steel containing about 25% Cr, the high temperature strength at 600 to 700 ° C is rather lower than that of 18-8 series stainless steel, and there is a problem of toughness deterioration due to σ phase precipitation. Furthermore, when the Cr content is about 25%, the corrosion resistance is not sufficient under a severe corrosive environment.
【０００４】比較的、耐食性が良好な合金としては、例
えば、特開昭59−153858号公報に開示されるように、Cr
含有量を30％程度に高め、必要に応じてNb、Taを含有さ
せた合金があるが、上述のような厳しい条件下で単管と
して適用するには高温強度が不足する。また、二重管と
して使用する場合には製造コストや信頼性の点で問題が
多い。As an alloy having relatively good corrosion resistance, for example, as disclosed in JP-A-59-153858, Cr is used.
Although there are alloys in which the content is increased to about 30% and Nb and Ta are contained as required, the high temperature strength is insufficient for application as a single tube under the severe conditions described above. Further, when used as a double pipe, there are many problems in terms of manufacturing cost and reliability.
【０００５】さらに、Cr含有量を30％程度に高める一
方、Mo、Ｗ、Zr、Taなどを添加することにより、高温強
度の向上を図ったものとして、特開昭60−100640号公
報、同61−174350号公報、同61−276948号公報および、
同64−55352 号公報などに開示されるような耐熱合金が
あるが、いずれもその強度は超高温高圧ボイラのような
過酷な使用環境下では十分とは言いがたい。Further, while increasing the Cr content to about 30% and adding Mo, W, Zr, Ta and the like to improve the high temperature strength, there is disclosed in JP-A-60-100640. 61-174350 and 61-276948, and
There are heat-resistant alloys such as those disclosed in Japanese Patent Laid-Open No. 64-55352, but their strengths cannot be said to be sufficient under severe operating environments such as ultra-high temperature and high pressure boilers.
【０００６】[0006]
【発明が解決しようとする課題】本発明の目的は、苛酷
な高温腐食環境下においても、十分な耐食性と優れた高
温強度をもつオーステナイト耐熱合金を提供することに
ある。SUMMARY OF THE INVENTION An object of the present invention is to provide an austenitic heat resistant alloy having sufficient corrosion resistance and excellent high temperature strength even under severe high temperature corrosion environment.
【０００７】[0007]
【課題を解決するための手段】本発明は、次の高クロム
オーステナイト耐熱合金を要旨とする。The present invention is summarized by the following high chromium austenitic heat resistant alloy.
【０００８】重量％で、Ｃ：0.02％を超え0.10％以下、
Si：1.0 ％以下、Mn：2.0 ％以下、Cr：28〜38％、Ni：
35〜60％、Ti:0.2〜1.0 ％、Ｎ：0.05％以下、Al：0.5
％を超え３％以下及びNb:0〜1.0 ％を含有し、更にＢ:
0.001〜0.01％及びZr：0.01〜0.1 ％の１種以上、Mo:0.
5〜3.0 ％及びＷ:1.0〜6.0 ％の１種以上、Mg：０〜0.0
5％及びCa:0〜0.05％の１種以上を含有し、残部はFe及
び不可避的不純物からなる高温強度と耐食性に優れた高
クロムオーステナイト耐熱合金。% By weight, C: more than 0.02% and 0.10% or less,
Si: 1.0% or less, Mn: 2.0% or less, Cr: 28 to 38%, Ni:
35-60%, Ti: 0.2-1.0%, N: 0.05% or less, Al: 0.5
% And 3% or less and Nb: 0 to 1.0%, and further B:
One or more of 0.001 to 0.01% and Zr: 0.01 to 0.1%, Mo: 0.
One or more of 5 to 3.0% and W: 1.0 to 6.0%, Mg: 0 to 0.0
A high chromium austenitic heat resistant alloy containing 5% and Ca: 0 to 0.05%, the balance being Fe and inevitable impurities, and having excellent high temperature strength and corrosion resistance.
【０００９】上記成分において、Nb、MgおよびCaはいず
れも無添加でもよい。これらを積極的に添加する場合、
含有量はNbで 0.1〜1.0 ％、MgおよびCaでいずれも 0.0
01〜0.05％の範囲とするのが望ましい。In the above components, Nb, Mg and Ca may all be added without any addition. When actively adding these,
The content is 0.1-1.0% for Nb, 0.0 for both Mg and Ca.
It is desirable to set it in the range of 01 to 0.05%.
【００１０】前述のような苛酷な高温腐食環境下で十分
な耐食性を得るためには、28％以上Crを含有させること
が必要である。このような高CrのCr−Ni−Fe系合金にお
いては、所定のNi含有量の範囲でα−Cr相が析出し、高
温強度向上に寄与する。In order to obtain sufficient corrosion resistance under the severe high temperature corrosive environment as described above, it is necessary to contain 28% or more of Cr. In such Cr-rich Cr-Ni-Fe alloys, the α-Cr phase precipitates within a predetermined Ni content range and contributes to the improvement of high temperature strength.
【００１１】本発明者らは、前記の従来の高Crオーステ
ナイト鋼のクリープ破断強度の飛躍的向上を目指して研
究を行った結果、次の知見を得た。The present inventors have conducted the research aiming at a dramatic improvement in the creep rupture strength of the above-mentioned conventional high Cr austenitic steel, and have obtained the following findings.
【００１２】Ti添加は、クリープ破断強度を著しく向
上させる。これは、Tiがα−Cr相析出を促進することに
よる。The addition of Ti significantly improves the creep rupture strength. This is because Ti promotes α-Cr phase precipitation.
【００１３】0.5 ％を超えるAlの添加は、クリープ破
断強度を大きく向上させる。これはγ′相が析出し、高
温強度向上に寄与するとともに、Alがα−Cr相の固溶限
を狭め、α−Cr相の析出が一層促進されるためである。Addition of Al in excess of 0.5% greatly improves creep rupture strength. This is because the γ'phase is precipitated and contributes to the improvement of the high temperature strength, and Al narrows the solid solution limit of the α-Cr phase, further promoting the precipitation of the α-Cr phase.
【００１４】TiとAlを適正な量で複合添加することに
より、特開昭60−100640号公報などに開示されているよ
うな合金を遙かにしのぐ高温強度を有する高耐食性合金
を得ることができる。By adding Ti and Al in an appropriate amount in combination, it is possible to obtain a highly corrosion-resistant alloy having a high temperature strength far superior to that of the alloy disclosed in JP-A-60-100640. it can.
【００１５】[0015]
【作用】以下、本発明の合金を構成する成分の作用効果
と、その適正含有量を前記のように定めた理由について
説明する。The function and effect of the constituents of the alloy of the present invention and the reason why the proper content is determined as described above will be described below.
【００１６】Ｃ：0.02％を超え0.10％以下 Ｃは、炭化物を形成して耐熱鋼として必要な引張強さや
クリープ破断強度を向上させるために有効な元素であ
る。しかし、Ｃ含有量が0.02％以下では上記の効果が得
られず、一方、0.10％を超えると合金の延性および靱性
の低下が大きくなる。よって、Ｃ含有量の範囲は0.02％
を超え0.10％以下とした。C: more than 0.02% and 0.10% or less C is an element effective for forming carbides and improving the tensile strength and creep rupture strength required for heat-resistant steel. However, if the C content is 0.02% or less, the above effect cannot be obtained, while if it exceeds 0.10%, the ductility and toughness of the alloy are greatly deteriorated. Therefore, the range of C content is 0.02%
Over 0.10%.
【００１７】Si：1.0 ％以下 Siは、脱酸のために必要な元素であり、また耐酸化性改
善にも寄与する元素である。Si含有量が1.0 ％を超える
と、溶接性や組織安定性が悪化する。これらの作用を考
慮してSi含有量は1.0 ％以下とした。脱酸と耐酸化性改
善の効果を得るための望ましい下限は0.05％である。Si: 1.0% or less Si is an element necessary for deoxidation and also contributes to the improvement of oxidation resistance. If the Si content exceeds 1.0%, the weldability and the structural stability deteriorate. Considering these effects, the Si content is set to 1.0% or less. The desirable lower limit for obtaining the effects of deoxidation and oxidation resistance improvement is 0.05%.
【００１８】Mn：2.0 ％以下 Mnは脱酸元素として有効な元素であるが、2.0 ％を超え
ると耐熱特性が劣化する。よって、Mn含有量は2.0 ％以
下とした。有効な脱酸と耐熱特性を得るための望ましい
下限は0.05％である。Mn: 2.0% or less Mn is an element effective as a deoxidizing element, but if it exceeds 2.0%, the heat resistance is deteriorated. Therefore, the Mn content is set to 2.0% or less. The desirable lower limit for obtaining effective deoxidation and heat resistance is 0.05%.
【００１９】Cr：28〜38％ Crは、耐酸化性、耐水蒸気酸化性または耐高温腐食性等
の耐食性改善に優れた作用を発揮し、さらに高温強度を
担うα−Cr相を形成する重要な元素である。しかし、そ
の含有量が28％未満では上記効果が得られず、一方、38
％を超えると加工性の劣化や組織の不安定を招く。よっ
て、Cr含有量の範囲は28〜38％とした。Cr: 28-38% Cr has an excellent effect in improving the corrosion resistance such as oxidation resistance, steam oxidation resistance or high temperature corrosion resistance, and is important for forming an α-Cr phase responsible for high temperature strength. Is an element. However, if its content is less than 28%, the above effect cannot be obtained, while on the other hand,
If it exceeds%, the workability deteriorates and the structure becomes unstable. Therefore, the Cr content range is set to 28 to 38%.
【００２０】Ni：35〜60％ Niは、安定なオーステナイト組織を得るために必要不可
欠な元素である。さらに、α−Cr相の析出を抑制する作
用を有する元素である。しかし、Ni含有量が35％未満で
あると、オーステナイト組織の確保が不安定になる。一
方、60％を超えるとα−Cr相の析出が抑制され、高温強
度が不足する上に、経済的にも多大な不利を招く。よっ
て、Ni含有量の範囲は35〜60％とした。Ni: 35-60% Ni is an essential element for obtaining a stable austenite structure. Further, it is an element having an action of suppressing the precipitation of the α-Cr phase. However, if the Ni content is less than 35%, it becomes unstable to secure the austenite structure. On the other hand, if it exceeds 60%, the precipitation of α-Cr phase is suppressed, the high temperature strength becomes insufficient, and a great economical disadvantage is brought about. Therefore, the range of Ni content is set to 35 to 60%.
【００２１】Ti： 0.2〜1.0 ％ Tiはα−Cr相析出に大きな影響を及ぼす重要な元素であ
る。Tiを含有させるとα−Cr相の析出は促進される。十
分な高温強度を示すα−Cr相量を確保するには、0.2 ％
以上のTi含有量が必要であるが、1.0 ％を超えると靱性
が低下する。よって、Ti含有量の範囲は 0.2〜1.0 ％と
した。Ti: 0.2 to 1.0% Ti is an important element which has a great influence on α-Cr phase precipitation. The inclusion of Ti promotes the precipitation of the α-Cr phase. In order to secure the amount of α-Cr phase showing sufficient high temperature strength, 0.2%
The above Ti content is required, but if it exceeds 1.0%, the toughness decreases. Therefore, the Ti content range is 0.2 to 1.0%.
【００２２】Ｎ：0.05％以下 Ｎは高温強度を改善するとともに、オーステナイト組織
を安定化するため、高価な元素であるNiの一部として代
替するのに有効な元素である。しかし、0.05％を超える
と、高温長時間使用時に窒化物が析出し靱性の低下をも
たらす。よってＮ含有量は0.05％以下とした。上記効果
を得るための望ましい下限は0.005 ％である。N: 0.05% or less N improves the high temperature strength and stabilizes the austenite structure, and is an element effective as a substitute for a part of the expensive element Ni. However, if it exceeds 0.05%, nitrides are precipitated during use at high temperature for a long time, resulting in a decrease in toughness. Therefore, the N content is set to 0.05% or less. The desirable lower limit for obtaining the above effect is 0.005%.
【００２３】Al：0.5 ％を超え３％以下 Alは、一般的には脱酸元素として含有させるが、0.5 ％
を超えて含有させることによりクリープ破断強度が大き
く改善される。これは、γ′相が析出し高温強度向上に
大きく寄与するとともに、α−Cr相の固溶限を狭め、α
−Cr相の析出を促進するためである。しかし、3.0 ％を
超えると靱性が著しく低下する。よってAl含有量の範囲
は0.5 ％を超え3.0 ％以下とした。Al: more than 0.5% and 3% or less Al is generally contained as a deoxidizing element, but 0.5%
If it is contained in excess of 1.0, the creep rupture strength is greatly improved. This is because the γ'phase is precipitated and contributes greatly to the improvement of high temperature strength, and the solid solubility limit of the α-Cr phase is narrowed.
This is to promote the precipitation of the Cr phase. However, if it exceeds 3.0%, the toughness is significantly reduced. Therefore, the Al content range was set to more than 0.5% and 3.0% or less.
【００２４】ＢおよびZr：Ｂは 0.001〜0.01％、Zrは0.
01〜0.1 ％ これらの元素は、主として合金の粒界強化に有効な元素
であり、１種だけを選んで添加してもよいし、２種複合
添加してもよい。Ｂ含有量が0.001 ％未満、Zr含有量が
0.01％未満では、上記効果が得られない。一方、Ｂ含有
量は0.01％、Zr含有量は0.1 ％を超えると、クリープ破
断強度も低下し、溶接性も劣化する。よって、含有量の
範囲は、Ｂで 0.001〜0.01％、Zrで0.01〜0.1 ％とし
た。B and Zr: B is 0.001 to 0.01% and Zr is 0.
01 to 0.1% These elements are mainly effective for strengthening the grain boundaries of the alloy, and one kind may be selected and added, or two kinds may be added in combination. B content is less than 0.001%, Zr content is
If it is less than 0.01%, the above effect cannot be obtained. On the other hand, when the B content exceeds 0.01% and the Zr content exceeds 0.1%, the creep rupture strength also decreases and the weldability also deteriorates. Therefore, the content range is 0.001 to 0.01% for B and 0.01 to 0.1% for Zr.
【００２５】MoおよびＷ：Moは 0.5〜3.0 ％、Ｗは 1.0
〜6.0 ％ MoおよびＷは、主として固溶強化元素として有効な元素
であり、クリープ破断強度を向上させる。これらの元素
は１種だけを選んで添加してもよいし、２種複合添加し
てもよい。Mo含有量が0.5 ％未満、Ｗ含有量が1.0 ％未
満では、上記効果が得られない。一方、Mo含有量は3.0
％、Ｗ含有量は6.0 ％を超えると、耐食性および加工性
を劣化させる。よって、Mo含有量の範囲は 0.5〜3.0
％、Ｗ含有量の範囲は 1.0〜6.0 ％とした。Mo and W: Mo is 0.5 to 3.0%, W is 1.0
˜6.0% Mo and W are mainly effective elements as solid solution strengthening elements and improve creep rupture strength. One of these elements may be selected and added, or two or more of them may be added in combination. If the Mo content is less than 0.5% and the W content is less than 1.0%, the above effect cannot be obtained. On the other hand, Mo content is 3.0
%, W content exceeding 6.0% deteriorates corrosion resistance and workability. Therefore, the Mo content range is 0.5 to 3.0.
%, And the W content range was 1.0 to 6.0%.
【００２６】ただし、これらを２種併用する場合には、
合計含有量をMo＋ (1/2)Ｗで 3.0％以下に抑えるのが望
ましい。However, when two kinds of these are used in combination,
It is desirable to keep the total content of Mo + (1/2) W to 3.0% or less.
【００２７】本発明合金は、前述の成分の他に、さらに
以下に述べる成分を含有させることができる。The alloy of the present invention may further contain the following components in addition to the above components.
【００２８】Nb：上限1.0 ％ Nbは結晶粒を微細化し、延性を向上させる。さらにオー
ステナイト相中やCr炭化物中に固溶してクリープ破断強
度の向上に寄与する。このため、必要に応じて用いるの
がよい。上記効果を得るために積極的に添加する場合
は、0.1 ％以上とするのが望ましい。しかし、Nb含有量
が1.0 ％を超えると靱性の劣化を招くのでその上限は1.
0 ％とした。Nb: 1.0% upper limit Nb refines crystal grains and improves ductility. Further, it forms a solid solution in the austenite phase and Cr carbide and contributes to the improvement of creep rupture strength. Therefore, it is preferable to use it as necessary. When it is positively added to obtain the above effect, it is desirable to set it to 0.1% or more. However, if the Nb content exceeds 1.0%, the toughness deteriorates, so the upper limit is 1.
It was set to 0%.
【００２９】MgおよびCa：Mgは上限0.05％、Caは上限0.
05％ MgおよびCaは加工性改善に有効な元素であり、必要に応
じて用いる。積極的に添加する場合、１種だけを選んで
添加してもよいし、２種複合添加してもよい。Mg and Ca: Mg has an upper limit of 0.05%, and Ca has an upper limit of 0.
05% Mg and Ca are effective elements for improving workability, and are used as necessary. When positively adding, only one kind may be selected and added, or two kinds may be added in combination.
【００３０】その際加工性の改善効果を得るには、下限
はMg、Caともに0.001 ％とするのが望ましい。At this time, in order to obtain the effect of improving the workability, it is desirable that the lower limits be 0.001% for both Mg and Ca.
【００３１】しかし、いずれも0.05％を超えると逆に加
工性を劣化させるので、ともに含有量の上限は0.05％と
した。ただし、MgとCaを２種併用する場合には、合計含
有量の範囲も 0.001〜0.05％とするのが望ましい。However, if the content of each exceeds 0.05%, the workability is deteriorated, so the upper limit of the content is set to 0.05%. However, when two kinds of Mg and Ca are used together, the total content range is preferably 0.001 to 0.05%.
【００３２】[0032]
【実施例】表１および表２に示す化学組成の合金を高周
波真空溶解炉で溶製して得た20kgインゴットを鍛造、冷
間圧延し、さらに1200℃で固溶化熱処理を施した供試材
から、各試験片を作製し、クリープ破断強度と時効後の
シャルピー衝撃値の測定試験を行った。[Example] A 20 kg ingot obtained by melting alloys having the chemical compositions shown in Tables 1 and 2 in a high frequency vacuum melting furnace, forged, cold rolled, and subjected to solution heat treatment at 1200 ° C. From the above, each test piece was prepared, and a measurement test of creep rupture strength and Charpy impact value after aging was performed.
【００３３】[0033]
【表１】 [Table 1]
【００３４】[0034]
【表２】 [Table 2]
【００３５】No.1〜28は本発明例、Ａ〜Ｊは比較例であ
る。なお、比較例Ｅ、Ｆは特開昭60-100640号公報に開
示される従来合金、比較例Ｇ、Ｈは特開昭61−174350号
公報に開示される従来合金、比較例Ｉは特開昭64−5535
2 号公報に開示される従来合金、比較例Ｊは特開昭61−
276948号公報に開示される従来合金である。Nos. 1 to 28 are examples of the present invention, and A to J are comparative examples. Comparative Examples E and F are conventional alloys disclosed in JP-A-60-100640, Comparative Examples G and H are conventional alloys disclosed in JP-A-61-174350, and Comparative Example I is JP-A-6-174350. 64-6535
The conventional alloy disclosed in Japanese Patent Laid-Open No. 2 and Comparative Example J are disclosed in JP-A-61-
It is a conventional alloy disclosed in Japanese Patent No. 276948.
【００３６】クリープ破断試験は、外径６mm、標点間距
離30mmの試験片を用いて、700 ℃で行い、103 時間のク
リープ破断強度を求めた。時効後のシャルピー衝撃試験
は、700 ℃、100 時間の条件で時効処理した供試材から
作製した厚さ５mm×幅10mm×長さ55mmの２mmＶノッチ形
成試験片を用いて、０℃で行った。The creep rupture test was conducted at 700 ° C. using a test piece having an outer diameter of 6 mm and a gauge length of 30 mm, and the creep rupture strength for 10 3 hours was obtained. The Charpy impact test after aging was carried out at 0 ° C. using a 2 mm V notch forming test piece having a thickness of 5 mm, a width of 10 mm and a length of 55 mm, which was prepared from a test material aged at 700 ° C. for 100 hours. .
【００３７】表３および表４に、クリープ破断強度と時
効後のシャルピー衝撃値を示す。Tables 3 and 4 show the creep rupture strength and the Charpy impact value after aging.
【００３８】[0038]
【表３】 [Table 3]
【００３９】[0039]
【表４】 [Table 4]
【００４０】図１は、クリープ破断強度に及ぼすAl含有
量の影響を示す図である。図２は、時効後シャルピー衝
撃値（靱性）に及ぼすAl含有量の影響を示す図である。
図３は、表３および表４の結果から、本発明例と比較例
の合金についてクリープ破断強度を比較した例を示す図
である。FIG. 1 is a graph showing the effect of Al content on creep rupture strength. FIG. 2 is a diagram showing the influence of the Al content on the Charpy impact value (toughness) after aging.
FIG. 3 is a diagram showing an example in which the creep rupture strengths of the alloys of the present invention example and the comparative example are compared from the results of Tables 3 and 4.
【００４１】図１から、0.5 ％を超えるAl添加によっ
て、クリープ破断強度の改善効果が顕著になることがわ
かる。しかし、Al含有量が３％を超えると、クリープ破
断強度の向上は飽和し、Al含有量が本発明範囲内の合金
と差がなくなる。その上、図２に示すとおり、靱性が大
きく低下する。From FIG. 1, it can be seen that the effect of improving the creep rupture strength becomes remarkable by adding Al in excess of 0.5%. However, when the Al content exceeds 3%, the improvement in creep rupture strength saturates, and there is no difference between the Al content and the alloys within the range of the present invention. Moreover, as shown in FIG. 2, the toughness is greatly reduced.
【００４２】図３に示すとおり、本発明例合金は、Al含
有量が 0.5％を超えるがTi含有量が0.2 ％未満である比
較例Ｅ、Ｆや、Ti含有量が 0.2％以上であるがAl含有量
が0.5 ％未満である比較例Ｇ〜Ｊに対して、非常に高い
クリープ破断強度を示すことが明らかである。これは、
本発明で定める組成においては、適正なTi含有量がα−
Cr相の析出を促進していること、また適正なAl含有量に
よりγ′相が析出して高温強度向上に大きく寄与してい
ること、このAlがさらにα−Cr相の固溶限を狭め、α−
Cr相の析出を一層促進していることによる。As shown in FIG. 3, the alloys of the present invention have Comparative Examples E and F in which the Al content exceeds 0.5% but the Ti content is less than 0.2%, and the Ti content is 0.2% or more. It is clear that for Comparative Examples G to J having an Al content of less than 0.5%, a very high creep rupture strength is exhibited. this is,
In the composition defined in the present invention, the proper Ti content is α-
It promotes the precipitation of Cr phase, and that the appropriate Al content causes the γ'phase to precipitate and contributes greatly to the improvement of high temperature strength.This Al further narrows the solid solution limit of the α-Cr phase. , Α-
This is because the precipitation of the Cr phase is further promoted.
【００４３】[0043]
【発明の効果】本発明の高クロムオーステナイト耐熱合
金は、苛酷な高温環境下においても優れたクリープ破断
強度を有する合金である。本合金は高クロムでもあるの
で、苛酷な高温腐食環境下での耐食性にも優れている。
この合金製単管は、従来合金製の二重管よりもコスト的
に有利で、しかも信頼性の高いものとなる。The high chromium austenitic heat resistant alloy of the present invention is an alloy having excellent creep rupture strength even in a severe high temperature environment. Since this alloy is also high chromium, it has excellent corrosion resistance in severe high temperature corrosive environments.
This alloy single pipe is more cost effective and more reliable than the conventional alloy double pipe.
【図１】クリープ破断強度に及ぼすAl含有量の影響を示
す図である。FIG. 1 is a diagram showing the influence of Al content on creep rupture strength.
【図２】時効後のシャルピー衝撃値に及ぼすAl含有量の
影響を示す図である。FIG. 2 is a diagram showing the influence of Al content on the Charpy impact value after aging.
【図３】実施例に示す各鋼種のクリープ破断強度を比較
した例を示す図である。FIG. 3 is a diagram showing an example in which creep rupture strengths of steel types shown in Examples are compared with each other.
Claims (1)
Si：1.0 ％以下、Mn：2.0 ％以下、Cr：28〜38％、Ni：
35〜60％、Ti:0.2〜1.0 ％、Ｎ：0.05％以下、Al：0.5
％を超え３％以下及びNb:0〜1.0 ％を含有し、さらに
Ｂ:0.001〜0.01％及びZr：0.01〜0.1 ％の１種以上、M
o:0.5〜3.0 ％及びＷ:1.0〜6.0 ％の１種以上、Mg：０
〜0.05％及びCa:0〜0.05％の１種以上を含有し、残部は
Fe及び不可避的不純物からなる高温強度と耐食性に優れ
た高クロムオーステナイト耐熱合金。1. By weight%, C: more than 0.02% and 0.10% or less,
Si: 1.0% or less, Mn: 2.0% or less, Cr: 28 to 38%, Ni:
35-60%, Ti: 0.2-1.0%, N: 0.05% or less, Al: 0.5
%, 3% or less and Nb: 0 to 1.0%, and further, one or more of B: 0.001 to 0.01% and Zr: 0.01 to 0.1%, M
One or more of o: 0.5-3.0% and W: 1.0-6.0%, Mg: 0
~ 0.05% and Ca: 0 ~ 0.05% of one or more, the balance is
High-chromium austenite heat-resistant alloy consisting of Fe and inevitable impurities with excellent high-temperature strength and corrosion resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12640794A JPH07331390A (en) | 1994-06-08 | 1994-06-08 | High chromium austenitic heat resistant alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12640794A JPH07331390A (en) | 1994-06-08 | 1994-06-08 | High chromium austenitic heat resistant alloy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07331390A true JPH07331390A (en) | 1995-12-19 |
Family
ID=14934396
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12640794A Pending JPH07331390A (en) | 1994-06-08 | 1994-06-08 | High chromium austenitic heat resistant alloy |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07331390A (en) |
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| FR2845098A1 (en) * | 2002-09-26 | 2004-04-02 | Framatome Anp | NICKEL-BASED ALLOY FOR ELECTRIC WELDING OF NICKEL ALLOYS AND WELDED STEEL STEELS AND USE THEREOF |
| JP2006291261A (en) * | 2005-04-07 | 2006-10-26 | Daido Steel Co Ltd | High strength fine wire, and method for producing the same |
| JP2008528806A (en) * | 2005-01-25 | 2008-07-31 | ハンチントン、アロイス、コーポレーション | Coated welding electrode with reduced ductility crack resistance and welds made therefrom |
| WO2009154161A1 (en) | 2008-06-16 | 2009-12-23 | 住友金属工業株式会社 | Heat-resistant austenitic alloy, heat-resistant pressure-resistant member comprising the alloy, and process for producing the same |
| EP2206796A1 (en) | 2008-12-25 | 2010-07-14 | Sumitomo Metal Industries Limited | Austenitic heat resistant alloy |
| WO2011071054A1 (en) | 2009-12-10 | 2011-06-16 | 住友金属工業株式会社 | Austenitic heat-resistant alloy |
| WO2013073423A1 (en) | 2011-11-15 | 2013-05-23 | 新日鐵住金株式会社 | Seamless austenite heat-resistant alloy tube |
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1994
- 1994-06-08 JP JP12640794A patent/JPH07331390A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2845098A1 (en) * | 2002-09-26 | 2004-04-02 | Framatome Anp | NICKEL-BASED ALLOY FOR ELECTRIC WELDING OF NICKEL ALLOYS AND WELDED STEEL STEELS AND USE THEREOF |
| EP1408130A1 (en) * | 2002-09-26 | 2004-04-14 | Framatome ANP | Nickel based alloy for electrical welding of nickel alloys and steels, welding wire and its use |
| JP2008528806A (en) * | 2005-01-25 | 2008-07-31 | ハンチントン、アロイス、コーポレーション | Coated welding electrode with reduced ductility crack resistance and welds made therefrom |
| JP2006291261A (en) * | 2005-04-07 | 2006-10-26 | Daido Steel Co Ltd | High strength fine wire, and method for producing the same |
| JPWO2009154161A1 (en) * | 2008-06-16 | 2011-12-01 | 住友金属工業株式会社 | Austenitic heat-resistant alloy, heat-resistant pressure-resistant member made of this alloy, and manufacturing method thereof |
| US8801877B2 (en) | 2008-06-16 | 2014-08-12 | Nippon Steel & Sumitomo Metal Corporation | Austenitic heat resistant alloy, heat resistant pressure member comprising the alloy, and method for manufacturing the same member |
| EP2287349A4 (en) * | 2008-06-16 | 2017-07-26 | Nippon Steel & Sumitomo Metal Corporation | Heat-resistant austenitic alloy, heat-resistant pressure-resistant member comprising the alloy, and process for producing the same |
| WO2009154161A1 (en) | 2008-06-16 | 2009-12-23 | 住友金属工業株式会社 | Heat-resistant austenitic alloy, heat-resistant pressure-resistant member comprising the alloy, and process for producing the same |
| JP4431905B2 (en) * | 2008-06-16 | 2010-03-17 | 住友金属工業株式会社 | Austenitic heat-resistant alloy, heat-resistant pressure-resistant member made of this alloy, and manufacturing method thereof |
| EP2206796A1 (en) | 2008-12-25 | 2010-07-14 | Sumitomo Metal Industries Limited | Austenitic heat resistant alloy |
| US8313591B2 (en) | 2008-12-25 | 2012-11-20 | Sumitomo Metal Industries, Ltd. | Austenitic heat resistant alloy |
| US8808473B2 (en) | 2009-12-10 | 2014-08-19 | Nippon Steel & Sumitomo Metal Corporation | Austenitic heat resistant alloy |
| WO2011071054A1 (en) | 2009-12-10 | 2011-06-16 | 住友金属工業株式会社 | Austenitic heat-resistant alloy |
| KR20140091061A (en) | 2011-11-15 | 2014-07-18 | 신닛테츠스미킨 카부시키카이샤 | Seamless austenite heat-resistant alloy tube |
| WO2013073423A1 (en) | 2011-11-15 | 2013-05-23 | 新日鐵住金株式会社 | Seamless austenite heat-resistant alloy tube |
| WO2013118585A1 (en) | 2012-02-08 | 2013-08-15 | 新日鐵住金株式会社 | Double pipe and welded structure utilizing same |
| WO2017037851A1 (en) * | 2015-08-31 | 2017-03-09 | 株式会社日立製作所 | Cr-BASED TWO-PHASE ALLOY AND PRODUCT USING SAID TWO-PHASE ALLOY |
| WO2019131954A1 (en) * | 2017-12-28 | 2019-07-04 | 日本製鉄株式会社 | Austenite-based heat-resistant alloy |
| CN111542639A (en) * | 2017-12-28 | 2020-08-14 | 日本制铁株式会社 | Austenitic heat-resistant alloy |
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