JPS6335759A - Geothermal turbine rotor material - Google Patents
Geothermal turbine rotor materialInfo
- Publication number
- JPS6335759A JPS6335759A JP17872186A JP17872186A JPS6335759A JP S6335759 A JPS6335759 A JP S6335759A JP 17872186 A JP17872186 A JP 17872186A JP 17872186 A JP17872186 A JP 17872186A JP S6335759 A JPS6335759 A JP S6335759A
- Authority
- JP
- Japan
- Prior art keywords
- rotor
- toughness
- strength
- geothermal
- steel
- 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.)
- Pending
Links
- 239000000463 material Substances 0.000 title claims abstract description 37
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 7
- 229910000851 Alloy steel Inorganic materials 0.000 claims abstract description 6
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 6
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 6
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 5
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 5
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 4
- 229910052742 iron Inorganic materials 0.000 claims abstract description 3
- 239000011651 chromium Substances 0.000 claims description 17
- 238000010791 quenching Methods 0.000 claims description 13
- 230000000171 quenching effect Effects 0.000 claims description 13
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 8
- 238000005496 tempering Methods 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 4
- 239000011572 manganese Substances 0.000 claims description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 2
- 239000011733 molybdenum Substances 0.000 claims description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims 1
- 230000007797 corrosion Effects 0.000 abstract description 13
- 238000005260 corrosion Methods 0.000 abstract description 13
- 229910052758 niobium Inorganic materials 0.000 abstract description 7
- 239000000203 mixture Substances 0.000 abstract description 3
- 230000002829 reductive effect Effects 0.000 abstract description 3
- 229910000831 Steel Inorganic materials 0.000 description 31
- 239000010959 steel Substances 0.000 description 31
- 238000001816 cooling Methods 0.000 description 9
- 239000010955 niobium Substances 0.000 description 9
- 229910001563 bainite Inorganic materials 0.000 description 8
- 230000007423 decrease Effects 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 7
- 238000005336 cracking Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000007789 gas Substances 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 238000005242 forging Methods 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 2
- 239000003129 oil well Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910001149 41xx steel Inorganic materials 0.000 description 1
- 229910003294 NiMo Inorganic materials 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 235000003599 food sweetener Nutrition 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000003765 sweetening agent Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Turbine Rotor Nozzle Sealing (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、Ｈ２Ｓ、 ＣＯ，等の不凝結ガスを有する腐
食性の高い蒸気を使用する蒸気タービンのロータに適用
されるロータ材に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotor material applied to a rotor of a steam turbine that uses highly corrosive steam containing non-condensable gases such as H2S and CO.
地熱蒸気の温度は、２５０℃以下であり、この温度範囲
は、火力蒸気タービンにおいては、低圧タービンの領域
に入る。第１表に現在使用されているロータ材の化学成
分を示す。The temperature of geothermal steam is 250° C. or lower, and this temperature range falls within the range of low-pressure turbines in thermal steam turbines. Table 1 shows the chemical composition of rotor materials currently used.
一般に低圧ロータ材としてはＮ ｉＭｏＶ 鋼（ＡｓＴ
ＭＡ ４７０ ｃｌａｓｓ ２．５及び４）、Ｎ ｉ
ＣｒＭｏ’／鋼（ＡｓＴＭＡ４７０ ｃｌａｓｓ ５．
６及び７）が使用されている。その理由は、ＮｉＭｏ’
Ｖ ｔＮは、２．５％以上、ＮｉＣｒＭｏＶ鋼について
は五２５〜４チと、Ｎ１の含有量が高いためである。す
なわちＮ１の含有量が高いと焼入性が大巾に改善され、
ロータ中心部まで充分に焼きが入ることと、Ｎ１が母地
に固溶し、母地の靭性を高めるため大型ロータの中心ま
で強度も高く、靭性が高くなるからである。In general, NiMoV steel (AsT
MA 470 class 2.5 and 4), Ni
CrMo'/Steel (AsTMA470 class 5.
6 and 7) are used. The reason is NiMo'
This is because the V tN is 2.5% or more, and the NiCrMoV steel has a high N1 content of 525 to 4%. In other words, when the N1 content is high, the hardenability is greatly improved,
This is because the rotor is sufficiently hardened to the center, and N1 is dissolved in the base material, increasing the toughness of the base material, resulting in high strength and toughness up to the center of the large rotor.
火力蒸気タービンでは、厳重な給水処理を施した給水よ
シ発生した蒸気すなわち、清浄な蒸気を使用している。Thermal steam turbines use clean steam generated from feed water that has undergone strict water treatment.
しかしながら、一方塊熱蒸気は、不凝結ガスとして、Ｈ
，ＳＳＣ’０２等を含有しており、又地熱蒸気は、湿シ
度が高く、ロータの大部分は、Ｈ２Ｓ％ＣＯ，が溶は込
んだｐＨの低い湿分にさらされることになる。Ｈ２Ｓが
、溶けこんだ水溶液中特にｐＨの低い酸性域の場合、従
来高強度鋼に硫化物応力腐食割れが発生し易く、特に、
Ｎ１が１チを越すと、その感受性が高くなることが酸性
油井配管及びメタンガスタンクに使用された材料の経験
及び研究により明らかにされている。However, on the other hand, lump hot steam is treated as a non-condensable gas by H
, SSC'02, etc., and the geothermal steam has a high degree of humidity, and most of the rotor is exposed to low pH moisture in which H2S%CO is dissolved. When H2S is dissolved in an aqueous solution, especially in an acidic region with a low pH, sulfide stress corrosion cracking is likely to occur in conventional high-strength steel, and in particular,
Experience and research on materials used in acid oil well piping and methane gas tanks has shown that susceptibility increases when N1 exceeds 1 inch.
地熱蒸気中の湿分中のＨ２Ｓは、酸性油井及び事故を起
したメタンガス中のＨ３Ｓ濃度よりも大１陥に低いが、
ロータという回転体では、大きな信頼性が、要求され、
Ｎ１が入った上述の火力。The H2S in the moisture in geothermal steam is one order of magnitude lower than the H3S concentration in the acid oil well and the methane gas that caused the accident.
A rotor, a rotating body, requires great reliability.
The above-mentioned firepower includes N1.
蒸）Ｃタービン低圧ロータ用ＮｉＭｏＶ ｓ４及びＮＩ
ＣｒＭｏＶ 鋼の採用を控える場合が多い。NiMoV s4 and NI for steam) C turbine low pressure rotor
CrMoV steel is often avoided.
したがって、地熱タービンロータとしては、Ｎｉの少な
いＣｒＭｏＶ ｍ（Ａｓ ＴＭＡ ４７０ｃｌａｓｓ
８ ）が、使用される場合が多い。Therefore, as a geothermal turbine rotor, CrMoV m (As TMA 470class
8) is often used.
ＣｒＭｏＶ鋼は、クリープ破断強度が高いので、高圧ロ
ータ材として使用されるが、靭性は低く、２ ｍ Ｖノ
ツチシャルピー試験における脆性−延性４移温度（脆性
破面率が５０チになる温度、以下ＦＡＴＴという。）は
８０℃を越えており、このままでは、低圧ロータとして
の性能を要する地熱クービンロータとしては、採用でき
ない。CrMoV steel has high creep rupture strength, so it is used as a high-pressure rotor material, but its toughness is low, and the brittle-ductile 4 transition temperature (temperature at which the brittle fracture area ratio becomes 50 degrees, below) in the 2 m V notch Charpy test. FATT) exceeds 80°C, and as it is, it cannot be used as a geothermal Kubin rotor, which requires performance as a low-pressure rotor.
したがって、熱処理を変更し、ＦＡＴＴを８０℃以下と
し、地熱タービンロータとしている。Therefore, the heat treatment was changed and the FATT was set to 80° C. or less, resulting in a geothermal turbine rotor.
すなわち、高圧ロータの焼入処理は、９５０〜９８０℃
、強制空冷として、組織を、上部ベイナイト又は、上部
ベイナイト＋フェライトとし、次に焼戻し処理を行ない
クリープ強度を高くしているのに対して、地熱ロータの
焼入処理は、８５０℃〜９５０℃、水冷として、組織を
、下部ベイナイト又は、下部ベイナイト＋マμテンサイ
ドとし、次に焼戻し処理を行ない室温強度及び靭性を確
保している。In other words, the quenching treatment of the high-pressure rotor is performed at 950 to 980°C.
For forced air cooling, the structure is made into upper bainite or upper bainite + ferrite, and then tempered to increase the creep strength, whereas the geothermal rotor is hardened at 850°C to 950°C. For water cooling, the structure is made into lower bainite or lower bainite + martenside, and then tempered to ensure room temperature strength and toughness.
ＣｒＭｏＶ鋼は、焼入処理の変更すなわち焼入温度の低
下によシ組織の粗大化を防止し、また冷却を水冷とし、
冷却速度を早め、下部ベイナイト又は、下部ベイナイト
＋マμテンサイドを得、焼戻しをすることによシ、組織
の軸かい焼戻し下部ベイナイト又は、焼戻し下部ベイナ
イト＋マｌＶｆンサイトにすることＫより窩い靭性（Ｆ
ＡＴＴ（８０℃）を得、地熱タービンロータとじて採用
されている。CrMoV steel prevents the coarsening of the structure by changing the quenching process, that is, lowering the quenching temperature, and uses water cooling for cooling.
By accelerating the cooling rate to obtain lower bainite or lower bainite + martenside, and then tempering, the structure becomes axially tempered lower bainite or tempered lower bainite + martinite, which has a more porous toughness. (F
ATT (80℃) and is used as a geothermal turbine rotor.
しかし、ＣｒＭｏＶ鋼は、Ｎ１ の入った低圧ロータ材
と異なり、焼入性が悪く、大型のロータ、及びさらに高
強度が要求される場合には靭性が低下するため、地熱タ
ービンロータとして信頼性が低下する。又、現状のロー
タにおいても、さらに靭性の高い材料が得られれば、さ
らに信頼性の高い地熱タービンロータとして実用化でき
る。However, unlike low-pressure rotor materials containing N1, CrMoV steel has poor hardenability, and its toughness decreases when used in large rotors or when even higher strength is required, making it unreliable as a geothermal turbine rotor. descend. Furthermore, if a material with even higher toughness can be obtained for the current rotor, it will be possible to put it into practical use as a more reliable geothermal turbine rotor.
本発明は、現有のＣｒＭｏＶ 鋼地熱タービンロータよ
シも靭性が優れ、又さらに、大型化、高強度化した場合
にも、十分な靭性を有する地熱タービンロータ材を提供
しようとするものである。The present invention aims to provide a geothermal turbine rotor material that is superior in toughness to the existing CrMoV steel geothermal turbine rotor and has sufficient toughness even when the rotor is made larger and has higher strength.
本発明者は、さきにＣｒＭｏＶ鋼の高温強度を有し、又
低温強度及び靭性の優れたいわゆる高低圧一体型ロータ
材を開発すべく研究を重ねた結果、２１／４ ＣｒＭｏ
ＶＮｂ 鋼を、高低圧一体型蒸気タービン用ロータ材（
特開昭６０−２４５７７２号）として提案した。ただし
、本ロータ材は、高温強度と低温強度及び低温靭性を共
有させようとするものであυ、高温強度への配慮がある
ため、成分設計的には、高温強度の必要性がない地熱タ
ービンロータとして用うる場合には、さらに改善の余地
がある。また、２１／４ ＣｒＭｏｖＮｂ鋼は、主とし
て火力蒸気タービン材料として開発されたもので、腐蝕
性を有するＨ、Ｓ。As a result of repeated research to develop a so-called high-low-pressure integrated rotor material that has the high-temperature strength of CrMoV steel and also has excellent low-temperature strength and toughness, the present inventor has developed a 21/4 CrMoV steel.
VNb steel is used as rotor material for high and low pressure integrated steam turbines (
It was proposed as JP-A No. 60-245772). However, this rotor material is intended to share high-temperature strength, low-temperature strength, and low-temperature toughness υ, and since there is consideration for high-temperature strength, it is suitable for geothermal turbines that do not require high-temperature strength in terms of component design. When used as a rotor, there is room for further improvement. In addition, 21/4 CrMovNb steel was mainly developed as a material for thermal power steam turbines, and has corrosive properties such as H and S.
ＣＯ，等の地熱蒸気に対する耐腐蝕性及び耐応力腐蝕割
れ性を考慮した改善が必要である。Improvements are required that take into consideration corrosion resistance against geothermal steam such as CO, and resistance to stress corrosion and cracking.
〔問題点を解決するための手段〕
本発明は、上述の蒸気タービン用ロータ材である２ １
／４ ＣｒＭｏＶＮｂ鋼を地熱タービン用として、つぎ
のように改良したものである。[Means for Solving the Problems] The present invention provides the above-mentioned rotor material for a steam turbine.
/4 CrMoVNb steel has been improved as follows for use in geothermal turbines.
（１）■の範囲を低目とする。(1) Set the range of ■ as low.
■は、２１／４ ＣｒＭｏＶＮｂ鋼の場合、高温強度を
増加させる元素として非常に重要な元素である。２１／
４ ＣｒＭｏＶＮｂ鋼ではコノためＶの範囲は（Ｌ１〜
α３５チとしており、高温強度を高めるためには１ｌＬ
２〜（Ｌ５５％のＶにし、焼入温度を、９５０℃以上と
し、ＶＣを十分に固溶した場合、焼戻し時に、安定した
緻密なり、 ｃ、 （ｖｃ ）を析出させることが最も
望ましい。しかし、２１／４ ＣｒＭｏＶＮｂ鋼の場合
、靭性への配慮があり、焼入温度を９３０℃に低下して
いるが、高温強度への配慮もあシ、大きくは低下してい
ない。一方、地熱タービンロータにおいては、高温強度
は必要なく焼入温度は、さらに低くし、細粒の状態で、
焼入を実施したほうが、靭性は上昇する。この場合、高
温強度を目標として、Ｖをｌ１ｌ−以上に高めると、未
固溶のＶＣが残り固溶のＣの濃度を下げるため、焼入性
は、低下し、又未固溶のＶＣは、室温の強度には寄与せ
ず、靭性を低下させる。したがって、本発明ではＶの量
を０．０５％以上ＣＬ１％未満とした。なお上記目的の
だめの焼入温度としては８５０〜９３０℃が非常に好ま
しい。(2) is a very important element in the case of 21/4 CrMoVNb steel as an element that increases high temperature strength. 21/
4 In CrMoVNb steel, the range of V is (L1 ~
α35 is used, and in order to increase high temperature strength, 1L
2~(L55% V, quenching temperature at 950°C or higher, and sufficient VC as a solid solution, it becomes stable and dense during tempering, and it is most desirable to precipitate c, (vc). However, In the case of 21/4 CrMoVNb steel, the quenching temperature has been lowered to 930°C due to consideration of toughness, but consideration has also been given to high-temperature strength and the decrease has not been significant.On the other hand, geothermal turbine rotor In this case, high-temperature strength is not required, and the quenching temperature is lowered to a fine grain state.
Toughness increases when quenching is performed. In this case, when high-temperature strength is targeted and V is increased to 11l- or higher, undissolved VC remains and the concentration of solid-dissolved C is lowered, resulting in a decrease in hardenability. , does not contribute to room temperature strength and reduces toughness. Therefore, in the present invention, the amount of V is set to 0.05% or more and less than 1% CL. Note that the quenching temperature for the above purpose is very preferably 850 to 930°C.
（２） Ｎｂ の範囲を低目とする
Ｎｂの固溶度は、低く、焼本温度の９００℃程度では、
約ｎ、ｏｏ３％であり結晶粒倣細化及び室温強度の上昇
という点では、この値よりわずかに多く添加しておけば
よい。多量の添加は、多量の未固溶の炭化物（ＮｂＣ）
’を増し、固溶したＣの低下による焼入性の低下及び未
固溶炭化物による靭性の低下につながるため好ましくな
い。したがって、Ｎｂの含有量はＣＬＯＯ５〜Ｑ、０５
％とした。(2) The solid solubility of Nb is low, and at the firing temperature of about 900℃,
It is about n,oo 3%, and it is sufficient to add slightly more than this value in terms of grain pattern refinement and increase in room temperature strength. Addition of a large amount causes a large amount of undissolved carbide (NbC)
', which leads to a decrease in hardenability due to a decrease in solid-dissolved C and a decrease in toughness due to undissolved carbide, which is undesirable. Therefore, the Nb content is CLOO5~Q,05
%.
（３） Ｎｉの低下
２１／４ ＣｒＭｏＶＮｂ鋼においては、Ｎ１はｃＬ１
〜１．５ ％となっている。しかしながら、腐食性を有
する地熱蒸気に対する耐食性及び耐応力腐食割れの点を
考慮して、Ｎ１は１チ以下とした。(3) Decrease in Ni 21/4 In CrMoVNb steel, N1 is cL1
~1.5%. However, in consideration of corrosion resistance against corrosive geothermal steam and resistance to stress corrosion cracking, N1 was set to 1 inch or less.
（４） Ｃｒの範囲拡大
Ｃｒは、２１／４ ＣｒＭｏＶＮｂ鋼では、１．８〜′
Ｌａｌとしているが、焼入温度を低下し、また７％Ｎｂ
を低下すれば、汲小１チでも十分にｃｒの焼入性の改善
効果が期待でき、優れた室温強度及び靭性が得られる。(4) Expansion of Cr range Cr is 1.8~' for 21/4 CrMoVNb steel.
Lal, but the quenching temperature was lowered and 7%Nb
By lowering the Cr hardenability, even a small amount of 1 inch can be expected to sufficiently improve the hardenability of Cr, and excellent room temperature strength and toughness can be obtained.
また、ｃｒを上昇し、さらに焼入性を改善できる。Further, it is possible to increase cr and further improve hardenability.
２１／４ ＣｒＭｏＶＮｂ ｆ１４では、クリープ破断
強度の改善が飽和するとして、最高を２．８チとしたが
、焼入性改善のためにはさらにＣｒを増してもよい。た
だし、五５チ以上になるとその効果は飽和し、これ以上
のＣｒは必要ない。For 21/4 CrMoVNb f14, the maximum value was set at 2.8 inches, assuming that the improvement in creep rupture strength is saturated, but Cr may be further increased to improve hardenability. However, when the amount exceeds 55 cm, the effect is saturated and no more Cr is needed.
そこでＣｒの範囲を拡大し、１〜五５チとした。Therefore, the range of Cr was expanded to 1 to 55 inches.
以上の改良によ）、８５０℃〜９５０℃で焼入し、その
後焼戻して、使用できる室温強度及び靭性が優れ、また
地熱蒸気中における耐食性及び耐応力腐食割れ性の優れ
た地熱タービン用ロータ材が得られる。Through the above improvements), a rotor material for geothermal turbines that is quenched at 850°C to 950°C and then tempered has excellent usable room temperature strength and toughness, as well as excellent corrosion resistance and stress corrosion cracking resistance in geothermal steam. is obtained.
すなわち本発明は、炭素（Ｌｆ５〜ｃＬ３％、シリコン
α３−以下、マンガン１．２チ以下、ニッケ／Ｉ／Ｑ、
１〜１％、クロム１〜Ｎ５％、 モ！Ｊ７”ｆ’ン０．
５〜１．５％、バナヅウＡ（ＬＯ３％以上Ｑ、１チ未満
、ニオビューム［Ｌｏｏ：ｓ〜（ＬＯ３％、残部鉄およ
び付随的不純物よシなる低合金鋼で、焼入れ焼戻し処理
を施こしてなることを特徴とする地熱蒸気タービン用ロ
ータ材である。That is, the present invention uses carbon (Lf 5 to cL 3%, silicon α3 or less, manganese 1.2 or less, nickel/I/Q,
1-1%, chromium 1-5%, Mo! J7"f'n0.
5 to 1.5%, Banazu A (LO3% Q, less than 1 inch, Niobium [Loo:s ~ (LO3%, balance iron and incidental impurities, low alloy steel, quenched and tempered) This is a rotor material for geothermal steam turbines, which is characterized by:
以下、本発明のロータ材の組成及びその含有量を限定し
た理由について説明する。The composition of the rotor material of the present invention and the reason for limiting its content will be explained below.
炭素（Ｃ）：Ｃは、焼入性を増大させ、耐力や靭性を確
保するためには、必要不可欠な元素であり、本発明ロー
タ材に必要な耐力や靭性を発現させるためには、ｌｌｌ
Ｌｌｓｔｓ以上必要であるが、あまシ多ｆｆ１Ｋ添加す
るとかえって靭性を害し、また加工性が悪くなるので、
その含有量を１１．１５〜（Ｌ５チとした。Carbon (C): C is an essential element in order to increase hardenability and ensure yield strength and toughness.
Although it is necessary to add more than Llsts, adding too much ff1K will actually harm the toughness and worsen the workability.
Its content was set at 11.15~(L5chi).
シリコン（８１） ： ８１は溶鋼の脱酸剤として、有
効な元素であるが、多く添加すると脱酸による生成物で
あるＳｉｎ、が鋼中に残存し、鋼の清浄度を害し靭性を
低下させるので、［Ｌ３−以下とした。Silicon (81): 81 is an effective element as a deoxidizing agent for molten steel, but if it is added in large quantities, Sin, a product of deoxidation, will remain in the steel, impairing the cleanliness of the steel and reducing its toughness. Therefore, it was set to [L3- or less].
マンガン（Ｍｕ） ： Ｍｎは溶鋼の脱酸剤として有効
であシ、また焼入性を増大させて、強度を高めるのに有
効な元素である。しかし、あまシ多く添加すると靭性及
び延性を害するのでその含有量を最大１．２チどした。Manganese (Mu): Mn is an effective element as a deoxidizing agent for molten steel, and is also effective in increasing hardenability and strength. However, adding a large amount of sweetener impairs toughness and ductility, so the content was set at a maximum of 1.2.
ニッケＡ／（Ｎｉ）：Ｎｉは、鋼の焼入れ性を増大させ
て強度を高めるのに有効な元素である。Nickel A/(Ni): Ni is an element effective in increasing the hardenability of steel and increasing its strength.
特に靭性向上に有効である。しかしＮ１が１チをこすと
、地熱蒸気中の耐食性及び耐応力腐食割れ性に対する信
頼性が落ちてくるので、その含有量を１１〜１％とした
。It is particularly effective in improving toughness. However, if N1 exceeds 1 inch, the reliability of corrosion resistance and stress corrosion cracking resistance in geothermal steam decreases, so the content was set at 11 to 1%.
クロム（Ｃｒ） ： Ｃｒは通常のロータ用低合金鋼の
添加元素として最も重要な元素である。Chromium (Cr): Cr is the most important element added to ordinary low alloy steel for rotors.
Ｃｒｔ’ｌｆ４に添加すると、耐食性を改善し、焼入性
を増大させて、室温における強度及び靭性を向上させる
。そのため、上述した理由によシＣｒの含有量を１〜五
５チとした。When added to Crt'lf4, it improves corrosion resistance, increases hardenability, and improves strength and toughness at room temperature. Therefore, for the above-mentioned reason, the Cr content was set to 1 to 55.
モリブデン（Ｍｏ） ： Ｍｏは、Ｃｒと同様に通常の
ロータ用低合金鋼の添加元素として、重要な元素である
。Ｍｏを鋼に添加すると、焼入性を増大し、また、焼戻
し時の焼戻し軟化抵抗を大きくして、室温の強度の増大
に有効である。またＭＯは０．５チ程度以上添加すると
、鋼の焼戻し脆性を阻止する元素として、非常に有効な
元素である。しかし、あまり多く添加するとその効果は
飽和しかえって靭性を害する。そこでロータ材が大型化
した場合の質量効果（焼入性）を考慮して、ＭＯの含有
量は０５〜１．５優とした。Molybdenum (Mo): Like Cr, Mo is an important element as an additive element in ordinary low-alloy steel for rotors. Adding Mo to steel increases hardenability, increases resistance to temper softening during tempering, and is effective in increasing strength at room temperature. Furthermore, when MO is added in an amount of about 0.5 mm or more, it is a very effective element for inhibiting temper brittleness of steel. However, if too much is added, the effect will be saturated and the toughness will be adversely affected. Therefore, in consideration of the mass effect (hardenability) when the rotor material becomes larger, the MO content was set to 0.05 to 1.5.
パナジューム（Ｖ）：ＶはＭＯと同様に常温における強
度を向上するのに有効な元素である。Panadium (V): Like MO, V is an element effective in improving strength at room temperature.
地熱タービンロータにおいては、上述したように、高温
強度は必要なく、また必要以上に添加すると焼入性を害
し、靭性も害する。このためＶの含有量は［ＬＯ３−以
上［１１４未満とした。As mentioned above, geothermal turbine rotors do not require high-temperature strength, and adding more than necessary impairs hardenability and toughness. Therefore, the V content was set to be [LO3- or more] [less than 114].
ニオビューム（Ｎｂ） ： ＮｂはＶと同様に室温の強
度の上昇、結晶粒の微細化による靭性の向上に有効でち
る。一方、上述したように本発明のロータ材の焼入温度
は、８５０℃〜９３０℃と低目に取るためＮｌ）の固溶
度は低くせいぜいα００３−程度である。したがって強
度の向上には０．００３％あればよく、また結晶粒微細
化の点でも、固溶度よシも若干高目でもよい。−したが
って、Ｎｂの含有量は（ＬＯＯ３−〜（ＬＯ５％とした
。Niobium (Nb): Like V, Nb is effective in increasing strength at room temperature and improving toughness by making crystal grains finer. On the other hand, as mentioned above, since the quenching temperature of the rotor material of the present invention is low, 850° C. to 930° C., the solid solubility of Nl) is low, at most about α003−. Therefore, 0.003% is sufficient to improve the strength, and the solid solubility may also be slightly higher in terms of crystal grain refinement. - Therefore, the Nb content was set to (LOO3-~(LO5%).
その他：Ｐ、Ｓ、Ｃｕなどは不純物元素として、避けら
れないものであり、これらは、できるだけ低い方が望ま
しい。Others: P, S, Cu, etc. are unavoidable impurity elements, and it is desirable that these be as low as possible.
以下に本発明の実施例を示す。 Examples of the present invention are shown below.
ｓｏｋｇ真空溶解炉で、５０ゆの鋼塊を製作し、この鋼
塊を１２００℃の温度範囲で鍛伸し、６０鱈角棒を得た
。この場合の鍛造比は３であシ、大型ロータの場合の鍛
造比と、はぼ一致する。A 50 yen steel ingot was produced in a sokg vacuum melting furnace, and this steel ingot was forged in a temperature range of 1200°C to obtain a 60 cod square bar. The forging ratio in this case is 3, which is almost the same as the forging ratio in the case of a large rotor.
木材を１２００℃で２時間加熱し、試験に供した。The wood was heated at 1200° C. for 2 hours and subjected to the test.
この角棒の化学分析結果を第２表に示す。The chemical analysis results of this square bar are shown in Table 2.
第２表に示す実施例のうち、Ｓ１〜憲３までが本発明の
ロータ材でｉ、Ａ４、ム５が比較例のロータ材である。Among the examples shown in Table 2, S1 to Ken3 are rotor materials of the present invention, and i, A4, and M5 are rotor materials of comparative examples.
なおム４は、ＣｒＭｏＶ ｆ：Ａ高圧ロータの成分で、
現在地熱タービンロータとして使用されておシ、憲５は
、特開昭６０−２４５７７２の高低圧一体型蒸気タービ
ン用ロータ材である。Note that 4 is a component of the CrMoV f:A high-pressure rotor,
Ken 5, which is currently used as a geothermal turbine rotor, is a rotor material for a high and low pressure integrated steam turbine disclosed in Japanese Patent Application Laid-Open No. 60-245772.
これ等の角棒から切り出した試験片に、ロータ中心部（
１５５０φ径ロータ）に相当する熱処理を実施した。な
お、焼戻し処理によυ、地熱タービンローりの設計に必
要な強度すなわち、［ＬＺｆｉ酎圧６耐〜７３ｋｇ／Ｉ
ＩＩＩｌｓニナルヨウニ調整した。The center of the rotor (
A heat treatment corresponding to a 1550φ diameter rotor was performed. In addition, the tempering process increases the strength required for the design of geothermal turbine rollers, that is, [LZfi pressure 6 to 73 kg/I]
IIIls were adjusted accordingly.
熱処理は、次の通りである。The heat treatment was as follows.
予備熱処理、溶体化処理：１０１０℃×２５時間、徐冷
（１５００℃ロータ空冷時の中心担当）
焼戻し＝７２０℃Ｘ２５時間、炉冷
最終熱処理、焼入処理：９１０℃×１０時間、冷却速度
８０℃／時間（８００℃〜３００℃間）焼戻し処理：Ｘ
℃Ｘ２５時間、炉冷
Ｘ℃：４１ ６５１℃、４２ ６６３℃、Ａ３６６５℃
、扁４６６０℃、４５ ６６０℃地熱タービンロータに
おいては要求される特性は、靭性であシ、５０ｋｇ溶解
材と大型ロータとの差が問題となるが、次の処理を実施
して、大型ロータの中心部担当の組織を得て、靭性を比
較した。Preliminary heat treatment, solution treatment: 1010°C x 25 hours, slow cooling (center in charge when air cooling the rotor at 1500°C) Tempering = 720°C x 25 hours, furnace cooling Final heat treatment, quenching treatment: 910°C x 10 hours, cooling rate 80 °C/hour (between 800 °C and 300 °C) Tempering treatment: X
°C x 25 hours, furnace cooling X °C: 41 651 °C, 42 663 °C, A3665 °C
The characteristics required for a geothermal turbine rotor of 4660℃ and 45660℃ are toughness, and the difference between 50kg melted material and a large rotor poses a problem. The tissues in charge of the center were obtained and their toughness was compared.
１）鍛造比を大型ロータ担当とした。1) The forging ratio was assigned to a large rotor.
１）１２００℃に２時間加熱し、現実のロータの熱扱い
を再現した。この処理により、結晶粒は、粗大化する。1) It was heated to 1200°C for 2 hours to reproduce the heat treatment of a real rotor. This treatment coarsens the crystal grains.
１１１）熱処理は、大型ロータ中心部相当した。111) The heat treatment was applied to the center of a large rotor.
第３表に各村の機械的性質を示す。Table 3 shows the mechanical properties of each village.
第３表から明らかなように各村ともに（Ｌ２％耐力は、
６５ ｋｇｆ／ｍ”〜７３ゆｆ／■２の間に入っておシ
、地熱タービンロータとして十分な強度を有している。As is clear from Table 3, in each village (L2% yield strength is
It has a strength of between 65 kgf/m'' and 73 kgf/m2, which is sufficient for use as a geothermal turbine rotor.
なお、一般の低圧ロータでは伸びは１６％以上、絞シが
４５％以上要求されるが、各村の伸び・絞シは、この値
を十分に満足している。一方、衝撃特性であるが、低圧
ロータのＦＡＴＴは、８０℃以下であシ、大型になる程
よυ低いＦＡＴＴが要求される。Note that a general low-pressure rotor is required to have an elongation of 16% or more and a reduction of 45% or more, but the elongation and reduction of each village fully satisfy these values. On the other hand, regarding impact characteristics, the FATT of a low-pressure rotor must be 80°C or less, and the larger the rotor, the lower the FATT required.
比較材４は、現状のＣｒＭｏＶ 鋼地熱タービンロータ
であるが、ＦＡＴＴは、７４℃と要求ぎりぎりであり、
地熱タービンロータが大型化した場合、若干信頼性の点
で問題があり、改善が必要である。Comparison material 4 is the current CrMoV steel geothermal turbine rotor, but the FATT is 74°C, which is just below the required level.
When geothermal turbine rotors become larger, there are some reliability problems that need improvement.
一方、本発明材は、Ｉ＆１５℃、煮２３０℃、ム３２５
℃とＦＡＴＴは低下し、靭性は大巾に改善されている。On the other hand, the material of the present invention was heated at I & 15℃, boiled at 230℃,
°C and FATT are reduced, and toughness is greatly improved.
第２表によれば、Ａ１とＡ２は、Ｃｒが約ｔ５％である
がＣが１２チの１１のほうがＣＩＩＬ２７チの４２より
大巾に改善されている。Ｃを低減すると、焼入時のＮｂ
の固溶度が増すため、強度を微細なＮｂＣで持つために
、靭性も高くなる。したがって本発明材においては、Ｃ
の低いほうが望ましい。Ａ３は、Ｃｒを２．２６チにし
たものであるが、Ｃｑ６が同等のＡ２より、ＦＡＴＴは
やや低目となっており、Ｃｒの焼入性硬化という点で、
やや優れている。Ａ５は、■が本発明材ム３より高くな
っているが、ＦＡＴＴが高くなっており、本発明材のＶ
の低減効果は一著しいことを示している。すなわち、地
熱タービンロータの大型化及び高強度化においては、本
発明材の如く、低目にするほうが望ましいことが分かる
。According to Table 2, A1 and A2 have a Cr of about t5%, but the C of 11 with 12 chips is much improved over 42 with CIIL 27 chips. When C is reduced, Nb during quenching
Since the solid solubility of NbC increases and the strength is provided by fine NbC, the toughness also increases. Therefore, in the material of the present invention, C
The lower the value, the better. A3 has 2.26 inches of Cr, but has a slightly lower FATT than A2 with the same Cq6, and in terms of hardenability of Cr,
Slightly better. A5 has a higher ■ than the inventive material M3, but has a higher FATT and the V of the inventive material.
This shows that the reduction effect is quite remarkable. That is, it can be seen that in order to increase the size and strength of the geothermal turbine rotor, it is preferable to use a material with a low thickness like the material of the present invention.
本発明の地熱タービン用ロータは、従来のＣｒＭｏＶ
鋼地熱タービンロータ材、２１／４ ＣｒＭｏＶＮｂ鋼
高低圧一体型蒸気タービン用ロータ材よりも靭性が優れ
ており、信頼性が高く、より高強度化、より大型化の地
熱タービン用として適している。The geothermal turbine rotor of the present invention is a conventional CrMoV rotor.
Steel geothermal turbine rotor material, 21/4 CrMoVNb steel has superior toughness and reliability than rotor material for high and low pressure integrated steam turbines, and is suitable for higher strength and larger geothermal turbines.
Claims (1)
ガン１．２％以下、ニッケル０．１〜１％、クロム１〜
３．５％、モリブデン０．５〜１．５％、バナジユーム
０．０３％以上０．１％未満、ニオビユーム０．００３
〜０．０３％、残部鉄および付随的不純物よりなる低合
金鋼で、焼入れ焼戻し処理を施こしてなることを特徴と
する地熱蒸気タービン用ロータ材。Carbon 0.15-0.3%, silicon 0.3% or less, manganese 1.2% or less, nickel 0.1-1%, chromium 1-1%
3.5%, molybdenum 0.5-1.5%, vanadium 0.03% or more and less than 0.1%, niobyum 0.003
1. A rotor material for a geothermal steam turbine, characterized in that it is made of a low alloy steel comprising ~0.03%, the balance being iron and incidental impurities, and subjected to a quenching and tempering treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17872186A JPS6335759A (en) | 1986-07-31 | 1986-07-31 | Geothermal turbine rotor material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17872186A JPS6335759A (en) | 1986-07-31 | 1986-07-31 | Geothermal turbine rotor material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6335759A true JPS6335759A (en) | 1988-02-16 |
Family
ID=16053407
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17872186A Pending JPS6335759A (en) | 1986-07-31 | 1986-07-31 | Geothermal turbine rotor material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6335759A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114262846A (en) * | 2021-12-13 | 2022-04-01 | 通裕重工股份有限公司 | Flywheel rotor material and flywheel rotor quenching and tempering heat treatment process |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5230716A (en) * | 1975-09-05 | 1977-03-08 | Toshiba Corp | Turbine rotor for geothermal power generation and its production |
| JPS5440225A (en) * | 1977-09-06 | 1979-03-29 | Kobe Steel Ltd | Low alloy steel for rotor shaft |
| JPS54107416A (en) * | 1978-02-10 | 1979-08-23 | Hitachi Ltd | Heat-resistant low alloy steel casting and its heating treatment |
| JPS5550430A (en) * | 1978-10-06 | 1980-04-12 | Hitachi Ltd | Turbine rotor for geothermal electric power generation |
| JPS5947361A (en) * | 1982-09-08 | 1984-03-17 | Kawasaki Steel Corp | Medium-alloy cr steel for environment of geothermal fluid |
| JPS605853A (en) * | 1983-06-22 | 1985-01-12 | Toshiba Corp | Material for rotor of turbine for geothermal-power generation |
| JPS60245772A (en) * | 1984-05-21 | 1985-12-05 | Mitsubishi Heavy Ind Ltd | Low alloy steel for rotor of integrated high and low pressure type steam turbine |
| JPS61143523A (en) * | 1984-12-17 | 1986-07-01 | Toshiba Corp | Manufacture of rotor for geothermal energy turbine |
-
1986
- 1986-07-31 JP JP17872186A patent/JPS6335759A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5230716A (en) * | 1975-09-05 | 1977-03-08 | Toshiba Corp | Turbine rotor for geothermal power generation and its production |
| JPS5440225A (en) * | 1977-09-06 | 1979-03-29 | Kobe Steel Ltd | Low alloy steel for rotor shaft |
| JPS54107416A (en) * | 1978-02-10 | 1979-08-23 | Hitachi Ltd | Heat-resistant low alloy steel casting and its heating treatment |
| JPS5550430A (en) * | 1978-10-06 | 1980-04-12 | Hitachi Ltd | Turbine rotor for geothermal electric power generation |
| JPS5947361A (en) * | 1982-09-08 | 1984-03-17 | Kawasaki Steel Corp | Medium-alloy cr steel for environment of geothermal fluid |
| JPS605853A (en) * | 1983-06-22 | 1985-01-12 | Toshiba Corp | Material for rotor of turbine for geothermal-power generation |
| JPS60245772A (en) * | 1984-05-21 | 1985-12-05 | Mitsubishi Heavy Ind Ltd | Low alloy steel for rotor of integrated high and low pressure type steam turbine |
| JPS61143523A (en) * | 1984-12-17 | 1986-07-01 | Toshiba Corp | Manufacture of rotor for geothermal energy turbine |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114262846A (en) * | 2021-12-13 | 2022-04-01 | 通裕重工股份有限公司 | Flywheel rotor material and flywheel rotor quenching and tempering heat treatment process |
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