JP3503996B2 - Coated superalloy gas turbine parts - Google Patents
Coated superalloy gas turbine partsInfo
- Publication number
- JP3503996B2 JP3503996B2 JP21617894A JP21617894A JP3503996B2 JP 3503996 B2 JP3503996 B2 JP 3503996B2 JP 21617894 A JP21617894 A JP 21617894A JP 21617894 A JP21617894 A JP 21617894A JP 3503996 B2 JP3503996 B2 JP 3503996B2
- Authority
- JP
- Japan
- Prior art keywords
- corrosion
- superalloy
- coating film
- coating
- gas turbine
- 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
Description
【０００１】[0001]
【産業上の利用分野】本発明は耐蝕コーティング被覆さ
れた被覆超合金ガスタービン部品に関する。FIELD OF THE INVENTION This invention relates to coated superalloy gas turbine components having a corrosion resistant coating.
【０００２】[0002]
【従来の技術】発電用ガスタービンはエネルギー資源の
有効利用の点から注目され、ガスタービンの高効率化の
研究開発が盛んに行われている。ガスタービンにおいて
は、燃焼機出口ガス温度が高いほど発電効率が上昇する
ため、ガスタービン入口温度の高温化が推進されてい
る。しかしながら、燃料からの腐食成分、流入空気から
の海塩腐食粒子混入による著しい高温腐食や高温酸化
は、ガスタービンを構成する高温機器、部品の材料、特
に動翼、靜翼の材料にとっては極めて過酷な使用環境と
なっている。従って、それ等の材料は耐熱性の向上は勿
論のこと燃焼ガスに対する耐蝕性の向上も要求される。
上記のような過酷な使用環境下において、特に動翼、静
翼基材のみで対応するには限界に達しており、高温耐蝕
コーティングに関する研究がなされている。2. Description of the Related Art Gas turbines for power generation have been attracting attention from the viewpoint of effective use of energy resources, and research and development for improving the efficiency of gas turbines have been actively conducted. In the gas turbine, the higher the combustor outlet gas temperature is, the higher the power generation efficiency is, so that the gas turbine inlet temperature is being increased. However, the remarkable high temperature corrosion and high temperature oxidation due to the inclusion of corrosive components from fuel and corrosive particles of sea salt from the inflowing air are extremely severe for the materials of high temperature equipment and parts that compose the gas turbine, especially for the blades and blades. It has become a use environment. Therefore, these materials are required to have not only improved heat resistance but also improved corrosion resistance to combustion gas.
Under the harsh use environment as described above, it has reached a limit to be able to deal with only the moving blade and the stationary blade base material, and researches on high temperature anticorrosion coating have been made.
【０００３】 図９はガスタービン動翼に作用する各種
要因、すなわちガスタービン動翼が受ける各種の負荷、
環境状況を示す図である。この図において、ガスタービ
ン動翼４には動翼４を長手方向に貫通して空気冷却孔５
が設けてある。タービン入口温度が１０００℃を超える
現在、上記の空気冷却は必須の条件である。空気冷却孔
５を流れる冷却空気により、動翼４には燃焼ガスとの温
度差によって大きな熱応力を３ａが生じると共に、さら
にタービンの回転に伴う遠心力３ｂも重量される。同時
に、高温酸化３ｃや酸化腐食３ｄ、また燃焼灰によるエ
ロージョン３ｅ等が問題となっている。一般に、前者の
熱応力６ａ、遠心力３ｂは高温強度に優れた動翼の超合
金基材（以下単に基材と呼ぶ）１により持たせ、後者の
高温酸化３ｃ、酸化腐食３ｄ、エロージョン３ｅは高温
耐蝕コーティング被覆６によって分担させることが考え
られている。従って、図１０に示すように超合金基材１
の表面に耐蝕コーティング被覆６が施されている。FIG. 9 shows various factors that act on the gas turbine blade, that is, various loads that the gas turbine blade receives.
It is a figure which shows an environmental condition. In this figure, the gas turbine rotor blade 4 has an air cooling hole 5 penetrating through the rotor blade 4 in the longitudinal direction.
Is provided. At present, when the turbine inlet temperature exceeds 1000 ° C., the above air cooling is an essential condition. The cooling air flowing through the air cooling holes 5, with the 3a large thermal stress by a temperature difference between the combustion gas generated in the rotor blade 4, a centrifugal force 3b further in accordance with the rotation of the turbine is also Weight. At the same time, high temperature oxidation 3c, oxidative corrosion 3d, erosion 3e due to combustion ash, etc. have become problems. Generally, the former thermal stress 6a and centrifugal force 3b are given by a superalloy base material (hereinafter simply referred to as base material) 1 of a moving blade excellent in high temperature strength, and the latter high temperature oxidation 3c, oxidative corrosion 3d and erosion 3e are It has been considered to share by the high-temperature corrosion-resistant coating covering 6. Therefore, as shown in FIG.
An anticorrosion coating 6 is applied to the surface of the.
【０００４】 耐蝕超合金被覆については、各種公知の
文献が見られる。例えば、特公昭６０−１３０５６号
（被覆超合金）、特開昭５９−６３３０３号（被覆超合
金）、特公平１−５９３４８号（溶射被覆超合金製品と
製法）、特開昭５３−１１２２３４号（溶射被覆超合金
製品と製法）など多数の耐蝕超合金被覆について提案さ
れている。ガスタービン部品、特にガスタービン動翼４
の耐蝕コーティング技術については、ＭＣｒＡｌＹ（Ｍ
はＮｉ、Ｃｏ、Ｆｅおよびその複合材）合金を、減圧プ
ラズマ溶射、真空蒸着、スパッタリング等の物理的蒸着
法によるプロセスによりコーティングされている。現在
では、多種の合金被膜の形成できる点から減圧プラズマ
溶射法が多用されている。減圧プラズマ溶射法は、従来
の大気中プラズマ溶射法に比べて不活性ガスの減圧下で
の溶射施工が可能であり、溶射材料の酸化や窒化を防止
することができ予定通りの正常な被膜を形成できる。ま
た、減圧下でのプラズマジェットは超音速流となり、緻
密で密着性の高い被膜を形成でき被膜に生じる残留応力
は低い。高い残留応力は被膜の密着強度、被膜自体の引
張強度の低下を招くとともに、形成できる被膜厚さにも
大きな影響をおよぼすおそれがある。Various known documents are available for corrosion resistant superalloy coatings. For example, JP-B-60-13056 (coated superalloy), Japanese Open Sho 59-63303 (coated superalloy), JP fairness 1-59348 (spray coating superalloy article and production method), JP 53-112234 A number of corrosion-resistant superalloy coatings have been proposed such as No. (spray coating superalloy product and manufacturing method). Gas turbine parts, especially gas turbine rotor blades 4
For corrosion resistant coating technology of MCrAlY (M
Are coated with Ni, Co, Fe and their alloys) by a process such as physical vapor deposition such as low pressure plasma spraying, vacuum deposition, and sputtering. At present, the low pressure plasma spraying method is widely used because it can form various alloy coatings. Compared with the conventional atmospheric plasma spraying method, the low-pressure plasma spraying method enables spraying under a reduced pressure of an inert gas, can prevent oxidation and nitriding of the sprayed material, and can form a normal coating as planned. Can be formed. Further, the plasma jet under reduced pressure becomes a supersonic flow, a dense and highly adherent coating can be formed, and the residual stress generated in the coating is low. The high residual stress causes a decrease in the adhesion strength of the coating and the tensile strength of the coating itself, and may also have a great influence on the film thickness that can be formed.
【０００５】[0005]
【発明が解決しようとする課題】ところが、耐蝕コーテ
ィング被覆６材料であるＭＣｒＡｌＹ合金材料の靭性や
疲労強度などの機械的性質は、ガスタービン動翼材料で
あるＮｉ系超合金材料に比して必ずしも優れているとは
言い難い。その結果、コーティング被膜（以下単に被膜
と呼ぶ）の寿命特性は、耐酸化性、耐蝕性以外に被膜に
生じる熱応力３ａや被膜強度などの機械的特性以外よっ
ても大きな影響を受ける。[SUMMARY OF THE INVENTION However, the mechanical properties such as toughness and fatigue strength of the M Cr AlY alloy material is a corrosion-resistant coating covering 6 material, compared to the Ni-based superalloy material is a gas turbine blade material It is hard to say that it is excellent. As a result, the life characteristics of the coating film (hereinafter, simply referred to as a film) are greatly affected by the mechanical stress such as thermal stress 3a and film strength other than oxidation resistance and corrosion resistance.
【０００６】 図１１および図１２はＭＣｒＡｌＹ合金
の被膜２に生じた亀裂７が超合金基材１まで進展してい
る状態を示す。被膜２の特性によって超合金基材１単独
の場合に比して、コーティング材料としての強度が顕著
に低下するおそれがある。従って、被膜材料の選択にお
いては、被膜２の耐酸化性、耐蝕性は勿論、基材１との
マッチングを図り、コーティング部材の強度特性につい
ても十分検討する必要がある。しかしながら、被膜自体
の特性については被膜２からの試験片作成が困難なこと
もあり、必ずしも十分に明らかにされていないのが現状
である。また、基材１とのマッチングやコーティング部
材としての強度特性についても、限られた被膜材料に関
しては実験的検討はなされているものの、必ずしも体系
的な研究が行われているものとは言い難い。特に、基材
１よりも線膨脹係数が高いコーティング材料を用いた場
合、熱応力３ａ発生の原因となり、引張残留応力が発生
する。特に、基材１に比して被膜２の線膨脹係数が大き
いと、熱サイクルを受けたときに冷却過程での引張残留
応力が発生し、被膜２に割れや剥離等を生じる原因とな
っている。さらに、基材１よりも弾性係数Ｅが高いコー
ティング材料を用いた場合には、亀裂の発生およびその
進展は加速されるおそれがある。FIGS. 11 and 12 show MCrA 1Y alloy.
2 shows a state in which the crack 7 generated in the coating film 2 has propagated to the superalloy base material 1. Depending on the characteristics of the coating film 2, the strength as a coating material may be significantly reduced as compared with the case where the superalloy base material 1 is used alone. Therefore, in selecting the coating material, it is necessary to consider not only the oxidation resistance and corrosion resistance of the coating 2 but also the strength characteristics of the coating member by matching with the base material 1. However, the characteristics of the coating itself have not been sufficiently clarified at present, because it is difficult to prepare a test piece from the coating 2. Also, regarding the matching with the base material 1 and the strength characteristics as a coating member, it is hard to say that systematic research is necessarily performed, although experimental studies have been conducted on limited coating materials. In particular, when a coating material having a coefficient of linear expansion higher than that of the base material 1 is used, thermal stress 3a is generated, and tensile residual stress is generated. In particular, when the coefficient of linear expansion of the coating film 2 is larger than that of the base material 1, tensile residual stress occurs in the cooling process when subjected to a heat cycle, which causes cracks or peeling of the coating film 2. There is. Furthermore, when a coating material having an elastic modulus E higher than that of the base material 1 is used, crack generation and its development may be accelerated.
【０００７】 本発明は上記の事情に基づきなされたも
ので、耐蝕コーティング被膜材料であるＭＣｒＡｌＹ合
金材料の靭性や疲労強度などの機械的性質や熱物性と、
ガスタービン動翼材料である超合金基材材料の機械的性
質や熱物性との最適化とを図ることにより、被膜に生じ
る引張残留応力を低減させ、被膜に生じる亀裂の発生、
進展を防止する被覆超合金ガスタービン部品を提供す
る。[0007] The present invention has been made based on the above circumstances, the mechanical properties and thermal properties such as toughness and fatigue strength of M CrAlY alloy material is a corrosion-resistant coating film material,
By optimizing the mechanical properties and thermophysical properties of the superalloy base material that is a gas turbine blade material, the tensile residual stress generated in the coating is reduced, and the occurrence of cracks in the coating,
Provided is a coated superalloy gas turbine component that prevents progress.
【０００８】[0008]
【課題を解決するための手段】本発明の被覆超合金ガス
タービン部品は、Ｎｉ基、Ｃｏ基、Ｆｅ基の少なくとも
一種類を主成分とした耐熱合金からなる超合金基材と、
この超合金基材表面に耐高温腐食性、耐高温酸化性、耐
熱衝撃性および熱遮蔽を目的としてＡｌ系、Ｃｏ系、Ｎ
ｉ系、Ｆｅ系の少なくとも一種類を主成分するＭＣｒＡ
ｌＹ合金を用いて形成された耐蝕コーティング被膜層と
からなる被覆超合金ガスタービン部品において、前記耐
蝕コーティング被膜層の形成に用いられる耐蝕コーティ
ング被膜材料として、前記超合金基材よりも低い弾性係
数を有する耐蝕コーティング被膜材料を用いて被覆し、
前記耐蝕コーティング被膜層に亀裂が生じても前記超合
金基材への亀裂進展を抑制することを特徴とする。A coated superalloy gas turbine component of the present invention comprises a superalloy base material made of a heat-resistant alloy containing at least one of Ni-base, Co-base and Fe-base as a main component,
The high-temperature corrosion resistance to the superalloy substrate surface, high-temperature oxidation resistance, thermal shock resistance and Al system for thermal shield, Co-based, N
MCrA containing at least one of i-based and Fe-based
In coating a superalloy gas turbine component consisting of <br/> the formed corrosion-resistant coating film layer using a lY alloy, the resistance
As corrosion-resistant coating film material used to form the corrosion coating film layer was coated with a corrosion-resistant coating film material having a lower modulus of elasticity than that of the superalloy substrate,
Even if the corrosion-resistant coating film layer is cracked,
It is characterized in that crack growth on the gold base material is suppressed .
【０００９】[0009]
【作用】上記構成の本発明の被覆超合金ガスタービン部
品においては、コーティング被膜材料とガスタービン動
翼材料との材料選択の最適化が図られ、被膜に生じる引
張残留応力を圧縮残留応力に変換し、被膜の割れおよび
剥離を防止するとともに被膜に生じる亀裂の進展を防止
する。In the coated superalloy gas turbine component of the present invention having the above structure, the material selection of the coating film material and the gas turbine blade material is optimized, and the tensile residual stress generated in the film is converted into the compressive residual stress. It prevents cracking and peeling of the coating and prevents the development of cracks in the coating.
【００１０】[0010]
【実施例】（実施例１）図１は本発明による最適耐蝕コ
ーティング被膜材料の選択図を示す。この図において、
室温での市販ＭＣｒＡｌＹ合金の被膜材料（減圧プラズ
マ溶射により形成した被膜）の線膨脹係数α２と超合金
基材（以下単に基材と呼ぶ）の線膨脹係数α１として、
その比α ２ ／α１を縦軸に、市販ＭＣｒＡｌＹ合金被膜
材料の弾性係数Ｅ２と基材１の弾性係数Ｅ１として、そ
のＥ２／Ｅ１を横軸にとって示してある。すなわち、超
合金ガスタービン部品への最適な耐蝕コーティング被膜
材料としては、基材より被膜材料の線膨脹係数αおよび
弾性係数Ｅが低い領域IVに位置する被膜材料を用いる。
基材よりも線膨脹係数αを低くするのは、基材と被膜の
線膨脹係数αの差は熱応力発生の原因となるからであ
る。特に、基材に比して被膜の線膨脹係数がαが大きい
と、熱サイクルを受けたときに冷却過程において引張残
留応力が発生し、被膜の剥離の原因となる。従って、基
材より材料の線膨脹係数αを小さくすることによって、
被膜の割れ、被膜の剥離を防止できる。また、基材より
も被膜材料の弾性係数Ｅを小さくしてあるのは、基材よ
り弾性係数の小さな被膜に亀裂が生じても、基材にまで
それが進展しないようにするためである。これは、亀裂
先端の応力拡大係数Ｋ１が小さくなり、基材への亀裂進
展速度が減少することによる。従って、基材より被膜材
料の弾性係数Ｅを小さくするものである。EXAMPLES Example 1 FIG. 1 shows a selection diagram of the optimum corrosion-resistant coating film material according to the present invention. In this figure,
As the linear expansion coefficient alpha 1 of the linear expansion coefficient alpha 2 and the superalloy substrate of the film material commercially available MCrAlY alloy (film formed by vacuum plasma spraying) (hereinafter simply referred to as substrate) at room temperature,
The ratio alpha 2 / alpha 1 on the vertical axis, as the elastic coefficient E 1 of the modulus of elasticity E 2 and the substrate 1 commercially available MCrAlY alloy coating material is shown that E 2 / E 1 abscissa. That is, as the optimum corrosion-resistant coating film material for the superalloy gas turbine component, a coating material located in the region IV where the linear expansion coefficient α and elastic modulus E of the coating material is lower than that of the base material is used.
The linear expansion coefficient α is made lower than that of the base material because the difference in the linear expansion coefficient α of the base material and the coating film causes the generation of thermal stress. In particular, when the coefficient of linear expansion α of the coating is larger than that of the base material, tensile residual stress is generated in the cooling process when subjected to a thermal cycle, which causes peeling of the coating. Therefore, by making the linear expansion coefficient α of the material smaller than that of the base material,
It is possible to prevent cracking of the coating and peeling of the coating. Further, the elastic modulus E of the coating material is made smaller than that of the base material so that even if a coating film having a smaller elastic modulus than the base material cracks, it does not propagate to the base material. This is because the stress intensity factor K 1 at the crack tip becomes small and the crack growth rate to the substrate decreases. Therefore, the elastic modulus E of the coating material is smaller than that of the base material.
【００１１】 図２は図１に示すところに従い選択した
被膜材料によって、超合金基材１に耐蝕コーティング被
覆したときの基材１と被膜２との断面図である。基材１
に基材１よりも低い線膨脹係数αを有する被膜材料を用
いて被覆することが有効な理由は、図３に示す汎用の有
限要素法熱弾性解析プログラムによる残留応力解析結果
から明らかである。解析では、円盤状の基材１表面に物
性値（弾性係数Ｅ、線膨脹係数α）の異なる被膜２が形
成された場合を解析対象としている。また、拡散熱処理
温度（１３９３Ｋ）から、均一室温まで冷却したときに
発生する熱応力を求めて残留熱応力とした。図中には、
コーティングを施した円盤の中心軸上での板厚方向の残
留応力分布を示す。但し、横軸には円周方向（半径方
向）応力成分σｔ（σｒ）を無次元応力パラメータによ
り整理して示す。円盤径Ｒに比して基材板厚Ｔが小さい
ため、横軸方向応力成分σｔは無視し得る程度に小であ
る。この図から明らかなように、被膜２と基材１の接合
界面３においてσｔ（σｒ）が大きな値を示し、被膜２
が薄くなるほど被膜２に生じる最大応力は高くなる傾向
を示す。一方、接合界面３の基材１側に生じる応力は被
膜側とは逆符号であり、被膜２が厚くなるほど応力は高
くなる傾向を示す。また、被膜２に生じる残留応力は
（基材線膨脹係数α１−被膜線膨脹係数α２）＞０の場
合に圧縮応力、（基材線膨脹係数α１−被膜線膨脹係数
α２）＜０の場合に引張応力となる。特に、基材１と被
膜２の線膨脹係数α差は熱応力発生の原因となり、基材
１に比して被膜２の線膨脹係数αが大きいと熱サイクル
を受けたときに冷却過程で引張残留応力が発生し、被膜
２の割れや剥離が生じる原因となる。したがって、基材
１と被膜２の線膨脹係数αの差は、（基材線膨脹係数α
１−被膜線膨脹係数α２）＞０になるようにし、被膜２
には圧縮の残留応力を付加することが有効である。FIG. 2 is a cross-sectional view of the base material 1 and the coating film 2 when the superalloy base material 1 is coated with a corrosion resistant coating with the coating material selected according to that shown in FIG. Substrate 1
The reason why coating with a coating material having a linear expansion coefficient α lower than that of the substrate 1 is effective is clear from the residual stress analysis result by the general-purpose finite element method thermoelasticity analysis program shown in FIG. In the analysis, the case where the coating film 2 having different physical property values (elastic coefficient E, linear expansion coefficient α) is formed on the surface of the disk-shaped substrate 1 is an analysis target. Further, the thermal stress generated when cooled to the uniform room temperature was obtained from the diffusion heat treatment temperature (1393K) and was taken as the residual thermal stress. In the figure,
The residual stress distribution in the plate thickness direction on the central axis of the coated disk is shown. However, the horizontal axis indicates the circumferential (radial direction) stress component σ t (σ r ) organized by the dimensionless stress parameter. Since the substrate plate thickness T is smaller than the disc diameter R, the stress component σ t in the horizontal axis direction is small enough to be ignored. As is clear from this figure, σ t (σ r ) shows a large value at the bonding interface 3 between the coating 2 and the substrate 1, and the coating 2
As the thickness becomes thinner, the maximum stress generated in the coating 2 tends to increase. On the other hand, the stress generated on the base material 1 side of the bonding interface 3 has the opposite sign to that on the coating film side, and the thicker the coating film 2, the higher the stress tends to be. Further, the residual stress generated in the coating 2 - compressive stress in the case of (base line expansion coefficient alpha 1 coat linear expansion coefficient alpha 2)> 0, (base line expansion coefficient alpha 1 - coating line expansion coefficient alpha 2) < When 0, the tensile stress is obtained. In particular, the difference in the linear expansion coefficient α between the base material 1 and the coating film 2 causes the generation of thermal stress, and if the linear expansion coefficient α of the coating film 2 is larger than that of the base material 1, it is stretched during the cooling process when subjected to a thermal cycle. Residual stress is generated, which causes cracking and peeling of the coating film 2. Therefore, the difference between the linear expansion coefficient α of the base material 1 and the film 2 is (the linear expansion coefficient α of the base material).
1 -Coating film linear expansion coefficient α 2 )> 0, coating film 2
It is effective to add a compressive residual stress.
【００１２】また、基材１の表面に基材１よりも小さな
弾性係数Ｅを有する被膜材料を用いて被覆することが有
効な理由は、図４に示す汎用の有限要素法を用いた応力
拡大係数Ｋ1 の弾性解析結果から明らかである。図にお
いて、基材１の厚さＴに対する被膜厚さｔの比ｔ／Ｔ＝
０．２の場合について、形状と材料の機械的特性の関数
Ｆ1 値を計算した結果である。図中、被膜弾性係数Ｅ2
／基材弾性係数Ｅ1 ＝１．０の結果は、片側亀裂を有す
る均質基材のＦ1 である。ここで、基材１よりも被膜２
の弾性係数が低い場合（被膜の弾性係数Ｅ2 ／基材の弾
性係数Ｅ1 ＜１．０）には、亀裂先端の応力拡大係数Ｋ
1 が低くなることは明らかである。これは、基材１より
も弾性係数Ｅの低い被膜２に亀裂が生じても、基材１１
へ亀裂が進展する過程において亀裂進展速度が減速され
る傾向にあることを示している。この亀裂進展の減速傾
向は、被膜２と基材１との接合界面３に向うほど顕著と
なることから、負荷応力によっては亀裂の被膜内停止が
生じることを示している。一方、基材１よりも被膜２の
弾性係数が高い場合（Ｅ2 ／Ｅ1 ＞１．０）には、逆に
Ｆ1 値は接合界面に向けて急増し、亀裂進展速度は加速
される傾向にあることが分る。接合界面３を通過しても
しばらくの間はＦ1 値は高めの値を示すが、亀裂が十分
に長ければ被膜材料による影響がなくなり、均質素材Ｆ
1 値と一致する傾向を示す。このような傾向は、被膜厚
さ比によって若干異なるが被膜厚さが薄いもの程、被膜
２に生じた亀裂の進展速度の減速傾向、増速傾向共に顕
著となる。従って、基材１よりも被膜２の弾性係数Ｅが
低い状態、すなわち被膜弾性係数Ｅ2 ／基材弾性係数Ｅ
1 ＜１．０とすることが有効である。The reason why it is effective to coat the surface of the substrate 1 with a coating material having an elastic modulus E smaller than that of the substrate 1 is that stress expansion using a general-purpose finite element method shown in FIG. It is clear from the elastic analysis result of the coefficient K 1 . In the figure, the ratio of the film thickness t to the thickness T of the substrate 1 t / T =
It is a result of calculating the function F 1 value of the mechanical properties of the shape and the material in the case of 0.2. In the figure, the film elastic modulus E 2
The result for / substrate elastic modulus E 1 = 1.0 is F 1 for a homogeneous substrate with one-sided cracks. Here, the coating film 2 rather than the base material 1
When the elastic modulus of is low (the elastic modulus of the coating film E 2 / the elastic modulus of the base material E 1 <1.0), the stress intensity factor K at the crack tip is
It is clear that 1 will be lower. This is because even if the coating film 2 having the elastic modulus E lower than that of the base material 1 cracks, the base material 11
It shows that the crack growth rate tends to be slowed down in the process of the crack growth. This tendency of deceleration of crack growth becomes more remarkable toward the bonding interface 3 between the coating film 2 and the base material 1, so that it is indicated that the cracking stops within the coating film depending on the load stress. On the other hand, when the elastic modulus of the coating film 2 is higher than that of the base material 1 (E 2 / E 1 > 1.0), on the contrary, the F 1 value rapidly increases toward the bonding interface and the crack growth rate is accelerated. It turns out that there is a tendency. The F 1 value shows a high value for a while even after passing through the bonding interface 3, but if the crack is sufficiently long, the influence of the coating material disappears and the homogeneous material F
Shows a tendency to match 1 value. Although such a tendency is slightly different depending on the film thickness ratio, the thinner the film thickness is, the more prominent the deceleration tendency and the higher speed tendency of the crack growth rate in the coating film 2 are. Therefore, the elastic modulus E of the coating film 2 is lower than that of the base material 1, that is, the coating elastic modulus E 2 / base material elastic modulus E
It is effective to set 1 <1.0.
【００１３】図５は本発明の基材１と被膜２の接合界面
３から被膜２の表面に向けて、被膜材料の線膨脹係数α
を連続的に変化させた場合の基材１と被膜２の断面図で
ある。先に示した図３の残留応力解析結果から明らかな
ように、被膜２と基材１との界面３には大きな残留応力
を生じる。この残留応力は、被膜２の剥離や割れに大き
く影響をおよぼすため、本発明においては基材１と被膜
２の膨脹係数差α1 −α2 によって残留応力を少なくし
ている。すなわち、α1 −α2 ＝０に近い状態とするこ
とによって、被膜２の剥離や割れを少なくしている。FIG. 5 shows the linear expansion coefficient α of the coating material from the bonding interface 3 between the substrate 1 and the coating 2 of the present invention toward the surface of the coating 2.
FIG. 5 is a cross-sectional view of the base material 1 and the coating film 2 in the case where is continuously changed. As is clear from the result of residual stress analysis shown in FIG. 3, a large residual stress is generated at the interface 3 between the coating film 2 and the base material 1. Since this residual stress has a great influence on the peeling and cracking of the coating film 2, the residual stress is reduced by the expansion coefficient difference α 1 -α 2 between the base material 1 and the coating film 2 in the present invention. That is, peeling and cracking of the coating film 2 are reduced by setting the state close to α 1 −α 2 = 0.
【００１４】 図６は基材１と被膜２との界面３より被
膜２の方向に向けて、被膜材料の弾性係数Ｅを連続的に
変化させた場合の基材１と被膜２の断面図である。左記
に示した図４の応力拡大係数Ｋ１弾性解析結果から明ら
かなように、基材１よりも被膜２の弾性係数Ｅが低い場
合（Ｅ２／Ｅ１＜１．０）には、応力拡大係数Ｋ１は低
くなり、基材１よりも弾性係数Ｅの低い被膜２に亀裂が
生じても、被膜内への亀裂が進展する過程において亀裂
進展速度は減速される。上記の減速は界面３に向かうほ
ど顕著となる。従って、本発明によれば亀裂の発生時に
被膜内停止を図ることが可能である。[0014] Figure 6 is in the direction of the film 2 from the interface 3 of the base material 1 and the film 2, a cross-sectional view of a substrate 1 and the film 2 when the elastic modulus E of the coating material is continuously changed Is. As is clear from the stress intensity factor K 1 elasticity analysis result of FIG. 4 shown on the left, when the elastic modulus E of the coating film 2 is lower than that of the base material 1 (E 2 / E 1 <1.0), the stress The expansion coefficient K 1 becomes low, and even if a crack is generated in the coating film 2 having an elastic modulus E lower than that of the base material 1, the crack growth rate is reduced in the process of the crack propagation into the coating film. The deceleration described above becomes more prominent toward the interface 3. Therefore, according to the present invention, it is possible to stop the inside of the film when a crack occurs.
【００１５】（実施例２）図７は本発明において被膜材
料の複合化を図った場合の基材１と被膜２との接合界面
３の断面図である。基材表面に被覆する被膜材料として
は、基材１よりも弾性係数Ｅの低い被膜材料を用いて中
間層Ａを形成する。この中間層Ａの弾性係数をＥA とす
る。この中間層Ａの上にこれよりも線膨脹係数αが低い
被膜材料を用いて表面層Ｂを形成する。この表面層Ｂの
線膨脹係数をαB とする。このようにすることにより、
基材１と被膜材料との接合界面３からの亀裂発生を防止
することができるとともに、最表面層Ｂの被膜２に亀裂
が生じた場合においても、基材１よりも弾性係数Ｅが低
い中間層Ａにおいて亀裂の進展が停止し、基材１への亀
裂の進展を防止することができる。(Embodiment 2) FIG. 7 is a cross-sectional view of a bonding interface 3 between a base material 1 and a coating film 2 when the coating material is made composite in the present invention. As the coating material for coating the surface of the base material, a coating material having a lower elastic coefficient E than that of the base material 1 is used to form the intermediate layer A. The modulus of elasticity of the intermediate layer A to E A. The surface layer B is formed on the intermediate layer A using a coating material having a linear expansion coefficient α lower than that of the intermediate layer A. The coefficient of linear expansion of the surface layer B is α B. By doing this,
It is possible to prevent the occurrence of cracks from the joint interface 3 between the base material 1 and the coating material, and even when the coating film 2 of the outermost surface layer B is cracked, the elastic modulus E is lower than that of the base material 1. The growth of cracks in the layer A stops, and the growth of cracks in the base material 1 can be prevented.
【００１６】 なお、図８は基材表面に被覆する被膜材
料のＡｌ＋Ｃｒ＋Ｔａ（ａｔｍ％）量を２４．５（ａｔ
ｍ％）とすることを示す図である。この図において、市
販ＭＣｒＡｌＹ合金コーティング被膜材料２ａの４点曲
げ試験結果を示したが、一般にＡｌ＋Ｃｒ＋Ｔａ量が増
加するほど耐酸化性が向上される。しかしながら、金属
間化合物などの生成によって酸化が顕著となり、図に示
すようにＡｌ＋Ｃｒ＋Ｔａ（ａｔｍ％）量が増加するほ
ど、４点曲げ強度は低下する傾向にある。逆にＡｌ＋Ｃ
ｒ＋Ｔａ（ａｔｍ％）の含有量が少ないと、弾性係数低
下のために強度低下を生じる。従って、被膜材料として
適正なＡｌ＋Ｃｒ＋Ｔａ（ａｔｍ％）の含有量を選定す
れば、室温付近でも高強度、高延性の被膜を得ることが
できる。すなわち、本発明によれば基材表面に被覆する
被膜材料のＡｌ＋Ｃｒ＋Ｔａ（ａｔｍ％）量を２４．５
（ａｔｍ％）限定することができる。In FIG. 8 , the amount of Al + Cr + Ta (atm%) of the coating material for coating the surface of the substrate is 24.5 (at).
FIG. In this figure, the results of the 4-point bending test of the commercially available MCrAlY alloy coating film material 2a are shown. Generally, as the amount of Al + Cr + Ta increases, the oxidation resistance improves. However, the oxidation becomes prominent due to the formation of intermetallic compounds, etc., and as shown in the figure, as the amount of Al + Cr + Ta (atm%) increases, the four-point bending strength tends to decrease. On the contrary, Al + C
When the content of r + Ta (atm%) is small, the strength decreases due to the decrease in elastic modulus. Therefore, by selecting an appropriate content of Al + Cr + Ta (atm%) as a coating material, a coating having high strength and ductility can be obtained even at around room temperature. That is, according to the present invention, the amount of Al + Cr + Ta (atm%) of the coating material coated on the surface of the base material is 24.5.
(Atm%) can be limited.
【００１７】超合金基材表面に耐蝕コーティング被覆を
施工する雰囲気圧力を減圧下とし、連続して耐蝕コーテ
ィングを連続して施工被覆する際には、減圧プラズマ溶
射を行う。減圧プラズマ溶射は、従来の大気圧プラズマ
溶射と異なり不活性ガス減圧下に溶射を行うものであ
り、溶射材料の酸化、窒化を防止することができ清浄な
被膜形成が可能である。また、減圧下でのプラズマジェ
ットは超音速流となり、緻密で密着性の高い被膜を形成
でき、被膜に生じる残留応力は少い。Atmospheric pressure for applying the anticorrosion coating on the surface of the superalloy substrate is reduced, and when continuously applying and coating the anticorrosion coating, low pressure plasma spraying is performed. Unlike the conventional atmospheric pressure plasma spraying, the low pressure plasma spraying is performed under a reduced pressure of an inert gas, and can prevent oxidation and nitriding of the sprayed material and can form a clean coating film. Further, the plasma jet under reduced pressure becomes a supersonic flow, a dense and highly adherent coating can be formed, and the residual stress generated in the coating is small.
【００１８】従って、超合金ガスタービン部品への最適
な耐蝕コーティング被膜材料である基材よりも線膨脹係
数、弾性係数が低い領域IVの材料を使用して、上記減圧
プラズマ溶射により被膜形成を行うときは、良好な被膜
を得ることができる。Therefore, a material in the region IV having a coefficient of linear expansion and an elastic coefficient lower than that of the base material, which is an optimum corrosion-resistant coating film material for superalloy gas turbine parts, is used to form a film by the above-mentioned low pressure plasma spraying. In some cases, a good coating can be obtained.
【００１９】[0019]
【発明の効果】上記から明らかなように、本発明によれ
ば耐蝕コーティング被膜材料であるＭＣｒＡｌＹ合金材
料の靭性や疲労強度などの機械的性質や熱物性と、ガス
タービン動翼材料である超合金材料の機械的性質や熱物
性との最適化を図ることにより、コーティング被膜に生
じる残留応力を低減させ、被膜の割れおよび剥離を防止
することができる。また、コーティング被膜に生じる亀
裂の発生および進展を防止し、従来の被覆超合金ガスタ
ービン部品に比較して、長時間の被膜寿命を有する被覆
超合金ガスタービン部品とすることができる。As is apparent from the above, according to the present invention, the mechanical properties such as toughness and fatigue strength of the MCrAlY alloy material, which is a corrosion-resistant coating film material, and thermophysical properties, and the superalloy, which is a material for gas turbine rotor blades. By optimizing the mechanical properties and thermophysical properties of the material, it is possible to reduce the residual stress generated in the coating film and prevent the film from cracking and peeling. Further, it is possible to prevent the occurrence and development of cracks that occur in the coating film, and to provide a coated superalloy gas turbine component having a longer coating life than the conventional coated superalloy gas turbine component.
【図１】本発明の最適コーティング被膜材料の選択を示
した図。FIG. 1 is a diagram showing the selection of the optimum coating film material of the present invention.
【図２】本発明の超合金基材表面に耐蝕コーティング被
覆した時の超合金基材と耐蝕コーティング被膜の断面
図。FIG. 2 is a cross-sectional view of a superalloy substrate and a corrosion-resistant coating film when the superalloy substrate surface of the present invention is coated with the corrosion-resistant coating.
【図３】本発明の汎用の有限要素法熱弾性解析プログラ
ムによる残留応力解析結果を示す図。FIG. 3 is a diagram showing a residual stress analysis result by a general-purpose finite element method thermoelasticity analysis program of the present invention.
【図４】本発明の汎用の有限要素法を用いた最適コーテ
ィング被膜材料に関する応力拡大係数Ｋ1 の弾性解析結
果を示す図。FIG. 4 is a diagram showing an elastic analysis result of a stress intensity factor K 1 for an optimum coating film material using the general-purpose finite element method of the present invention.
【図５】本発明のコーティング被膜材料の線膨脹係数を
連続的に変化させた場合の超合金基材と耐蝕コーティン
グ被膜との断面図。FIG. 5 is a sectional view of a superalloy substrate and a corrosion-resistant coating film when the linear expansion coefficient of the coating film material of the present invention is continuously changed.
【図６】本発明のコーティング被膜材料の弾性係数を連
続的に変化させた場合の超合金基材と耐蝕コーティング
被膜の断面図。FIG. 6 is a sectional view of a superalloy substrate and a corrosion-resistant coating film when the elastic modulus of the coating film material of the present invention is continuously changed.
【図７】本発明の耐蝕コーティング被膜材料の複合化を
行った時の超合金材料と耐蝕コーティング被膜の断面
図。FIG. 7 is a sectional view of the superalloy material and the corrosion-resistant coating film when the corrosion-resistant coating film material of the present invention is compounded.
【図８】 耐蝕コーティング被膜材料のＡｌ＋Ｃｒ＋Ｔ
ａ（ａｔｍ％）量の最適含有量を示す図。[8] of the anti corrosion coating film material Al + Cr + T
The figure which shows the optimal content of a (atm%) amount.
【図９】ガスタービン動翼が受ける各種の負荷、環境を
示す図。FIG. 9 is a diagram showing various loads and environments that the gas turbine rotor blade receives.
【図１０】ガスタービン動翼への耐蝕コーティングを示
す図。FIG. 10 is a view showing a corrosion-resistant coating on a gas turbine blade.
【図１１】 ＭＣｒＡｌＹ合金被膜に生じた亀裂がＮｉ
系超合金材料基材まで進展している状態を示す図。FIG. 11: Cracks formed in the MCrAl Y alloy coating are Ni
The figure which shows the state which has advanced to the base superalloy material base material.
【図１２】図１１の亀裂の拡大図。FIG. 12 is an enlarged view of the crack of FIG. 11.
１………超合金基材 ２………耐蝕コーティング被膜 ３………接合界面 ３ａ……熱応力 ３ｂ……遠心力 ３ｃ……高温酸化 ３ｄ……酸化腐食 ３ｅ……エロージョン ４………ガスタービン動翼 ５………冷却空気孔 ６………耐蝕コーティング被覆 ７………亀裂 Ａ………中間層 Ｂ………表面層1 ... Superalloy substrate 2 ... Corrosion resistant coating 3 ... Bonding interface 3a ... Thermal stress 3b ... Centrifugal force 3c ... High temperature oxidation 3d ... Oxidation corrosion 3e ... Erosion 4 ... Gas Turbine blade 5 ... Cooling air hole 6 ... Corrosion resistant coating 7 ... Crack A ... Intermediate layer B ... Surface layer
───────────────────────────────────────────────────── フロントページの続き (72)発明者 石渡 裕 神奈川県横浜市鶴見区末広町２の４ 株 式会社東芝 京浜事業所内 (72)発明者 田村 雅貴 神奈川県横浜市鶴見区末広町２の４ 株 式会社東芝 京浜事業所内 (56)参考文献 特開 平５−132751（ＪＰ，Ａ) 特開 平５−148609（ＪＰ，Ａ) 特開 昭55−161041（ＪＰ，Ａ) 特開 昭61−143576（ＪＰ，Ａ) 特開 平６−57399（ＪＰ，Ａ) 特開 平１−195267（ＪＰ，Ａ) 特公 平４−47018（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.7，ＤＢ名) F01D 5/28,9/02,25/00 F02C 7/00 F23R 3/42 C23C 4/00 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yutaka Ishiwata 4-4, 2 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Keio Works, Toshiba Corporation (72) Inventor Masaki Tamura 4-4, Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa (56) References Japanese Patent Laid-Open No. 5-132751 (JP, A) Japanese Patent Laid-Open No. 5-148609 (JP, A) Japanese Patent Laid-Open No. 55-161041 (JP, A) Japanese Patent Laid-Open No. 61- 143576 (JP, A) JP-A-6-57399 (JP, A) JP-A-1-195267 (JP, A) JP-B-4-47018 (JP, B2) (58) Fields investigated (Int.Cl. 7 , DB name) F01D 5 / 28,9 / 02,25 / 00 F02C 7/00 F23R 3/42 C23C 4/00
Claims (4)
種類を主成分とした耐熱合金からなる超合金基材と、こ
の超合金基材表面に耐高温腐食性、耐高温酸化性、耐熱
衝撃性および熱遮蔽を目的としてＡｌ系、Ｃｏ系、Ｎｉ
系、Ｆｅ系の少なくとも一種類を主成分するＭＣｒＡｌ
Ｙ合金を用いて形成された耐蝕コーティング被膜層とか
らなる被覆超合金ガスタービン部品において、前記耐蝕コーティング被膜層の形成に用いられる 耐蝕コ
ーティング被膜材料として、前記超合金基材よりも低い
弾性係数を有する耐蝕コーティング被膜材料を用いて被
覆し、前記耐蝕コーティング被膜層に亀裂が生じても前
記超合金基材への亀裂進展を抑制することを特徴とする
被覆超合金ガスタービン部品。1. A superalloy base material made of a heat-resistant alloy containing at least one of Ni-base, Co-base, and Fe-base as a main component, and the superalloy base material surface has high-temperature corrosion resistance, high-temperature oxidation resistance, and heat resistance. impact resistance and Al system for thermal shield, Co-based, Ni
MCrAl containing at least one of Fe and Fe
In the corrosion-resistant coating film layer with or <br/> Ranaru coated superalloy gas turbine components formed by using a Y alloy, as a corrosion coating film material used for forming the corrosion-resistant coating film layer, from the superalloy substrate Is coated with a corrosion-resistant coating film material having a low elastic modulus, and even if the corrosion-resistant coating film layer is cracked,
A coated superalloy gas turbine component, characterized in that it suppresses crack growth into a superalloy substrate .
金基材界面より前記耐蝕コーティング被膜表面層に向け
て弾性係数が連続的に低下し、前記耐蝕コーティング被
膜層に亀裂が生じても前記超合金基材への亀裂進展を抑
制することを特徴とする請求項１記載の被覆超合金ガス
タービン部品。Wherein said corrosion-resistant coating film layer is lowered elastic coefficient continuously toward said superalloy substrate wherein the corrosion coating film surface layer than the interface, the corrosion coating to be
Even if cracks occur in the film layer, crack propagation to the superalloy substrate is suppressed.
Coated superalloy gas turbine component according to claim 1, characterized in that control.
種類を主成分とした耐熱合金からなる超合金基材と、こ
の超合金基材表面に耐高温腐食性、耐高温酸化性、耐熱
衝撃性および熱遮蔽を目的としてＡｌ系、Ｃｏ系、Ｎｉ
系、Ｆｅ系の少なくとも一種類を主成分するＭＣｒＡｌ
Ｙ合金を用いて前記超合金基材側から順に形成される中
間層および表面層を有する耐蝕コーティング被膜層とか
らなる被覆超合金ガスタービン部品において、前記中間層を形成するための耐蝕コーティング被膜材料
として前記超合金基材よりも弾性係数の低い耐蝕コーテ
ィング被膜材料を用い、前記中間層に亀裂が生じても前
記超合金基材への亀裂進展を抑制するとともに、 前記表面層を形成するための耐蝕コーティング被膜材料
として前記中間層よりも線膨脹係数の低い耐蝕コーティ
ング被膜材料を用い、前記中間層と前記表面層との界面
に生じる残留応力を低減すること を特徴とする被覆超合
金ガスタービン部品。3. A superalloy base material made of a heat-resistant alloy containing at least one of Ni-base, Co-base, and Fe-base as a main component, and the superalloy base material surface has high-temperature corrosion resistance, high-temperature oxidation resistance, and heat-resistance. impact resistance and Al system for thermal shield, Co-based, Ni
MCrAl containing at least one of Fe and Fe
Formed in sequence from the superalloy substrate side using Y alloy
Between layer and either a corrosion-resistant coating film layer <br/> Ranaru coated superalloy gas turbine component having a surface layer, the corrosion-resistant coating film material for forming the intermediate layer
As a corrosion-resistant coat with a lower elastic modulus than the superalloy substrate as
Even if the intermediate layer is cracked, the
Corrosion-resistant coating film material for forming the surface layer while suppressing crack growth to the superalloy substrate
As a corrosion-resistant coating having a linear expansion coefficient lower than that of the intermediate layer
Interface between the intermediate layer and the surface layer using a coating material
A coated superalloy gas turbine component, which is characterized by reducing residual stress generated in the steel.
圧溶射によって行ったことを特徴とする請求項１ないし
請求項３記載の被覆超合金ガスタービン部品。Wherein said claims 1 to cover superalloy gas turbine component of claim 3, wherein the formation of the corrosion-resistant coating film layer is characterized in that performed by vacuum spraying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21617894A JP3503996B2 (en) | 1994-09-09 | 1994-09-09 | Coated superalloy gas turbine parts |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21617894A JP3503996B2 (en) | 1994-09-09 | 1994-09-09 | Coated superalloy gas turbine parts |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0874504A JPH0874504A (en) | 1996-03-19 |
| JP3503996B2 true JP3503996B2 (en) | 2004-03-08 |
Family
ID=16684515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21617894A Expired - Fee Related JP3503996B2 (en) | 1994-09-09 | 1994-09-09 | Coated superalloy gas turbine parts |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3503996B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7854966B2 (en) | 2006-02-06 | 2010-12-21 | Hamilton Sundstrand Corporation | Coating process for fatigue critical components |
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1994
- 1994-09-09 JP JP21617894A patent/JP3503996B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0874504A (en) | 1996-03-19 |
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