EP1770182B1 - Acier coulé à haute résistance mécanique et résistant à la chaleur ainsi que son procédé de fabrication et ses applications - Google Patents

Acier coulé à haute résistance mécanique et résistant à la chaleur ainsi que son procédé de fabrication et ses applications Download PDF

Info

Publication number
EP1770182B1
EP1770182B1 EP06020264A EP06020264A EP1770182B1 EP 1770182 B1 EP1770182 B1 EP 1770182B1 EP 06020264 A EP06020264 A EP 06020264A EP 06020264 A EP06020264 A EP 06020264A EP 1770182 B1 EP1770182 B1 EP 1770182B1
Authority
EP
European Patent Office
Prior art keywords
steam
steam turbine
pressure
steel
heat resisting
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
Application number
EP06020264A
Other languages
German (de)
English (en)
Other versions
EP1770182A1 (fr
Inventor
Masahiko c/o Hitachi Ltd. Int. Prop. Group Arai
Hirotsugu c/o Hitachi Ltd. Int. Prop. Group Kawanaka
Hideo c/o Hitachi Ltd. Int. Prop. Group Yoda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Publication of EP1770182A1 publication Critical patent/EP1770182A1/fr
Application granted granted Critical
Publication of EP1770182B1 publication Critical patent/EP1770182B1/fr
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt

Definitions

  • the present invention relates to a high-strength heat resisting cast steel which has high creep rupture strength at temperatures of 620°C or above and good weldability, and which is suitable for use in high- and intermediate-pressure inner casings of an ultra super critical (USC) pressure steam turbine and respective casings of a main steam valve and a steam control valve used in the USC pressure steam turbine in which temperature and pressure of main steam are not lower than 620°C and 25 MPa, respectively. Also, the present invention relates to a method of producing that steel, a steam turbine casing, a main steam valve and its casing, and a steam control valve and its casing, each casing being made of that steel, as well as a steam turbine power plant using those components.
  • USC ultra super critical
  • Patent Document 1 JP,A 7-118812 discloses a casing made of 9%-Cr steel, but the disclosed casing has a variation in high-temperature strength.
  • the steam temperature is 600°C and the steam pressure is 25 MPa.
  • As rotor materials there are known 1Cr-1Mo-1/4V ferrite-base low-alloy forged steel and 11Cr-1Mo-V-Nb-N forged steel.
  • Patent Document 2 JP,A 62-180044
  • Patent Document 3 JP,A 2-290950
  • Patent Document 4 JP,A 4-371551
  • Patent Document 5 JP,A 9-59747
  • High Chromium ferritic heat resistant steels are disclosed in JP-A 9 921 308 , JP-A 5 263 196 , JP-A 7 286 246 , JP-A 7 286 247 and JP-A 2001 192 781 .
  • Patent Document 5 discloses the martensite steel as a material having higher high-temperature strength than the above-mentioned known casing materials.
  • the disclosed martensite steel is not sufficient in strength when used for the casing of the steam turbine with steam temperature of 620°C. This leads to the problem that the thickness of the casing must be increased and larger thermal stress is caused when the turbine is started and stopped.
  • Patent Document 5 discloses materials of the rotor and the casing, etc., it pays no consideration to a steam turbine and a thermal power plant system adapted for an increased level of temperature.
  • An object of the present invention is to provide a high-strength heat resisting cast steel which has high creep rupture strength at temperatures of 620°C or above, high toughness and good weldability, a method of producing the steel, a steam turbine casing, a main steam valve and its casing, and a steam control valve and its casing, each casing being made of that steel, as well as a steam turbine power plant using those components.
  • the present invention provides a high-strength heat resisting cast steel according to claim 1.
  • the present invention provides a steam turbine casing, a main steam valve and its casing, and a steam control valve and its casing, each casing being made of that steel. casing, and a steam control valve and its casing, each casing being made of that steel.
  • values of [W/(Mo + 0.5W)] and (Co/W) are not larger than the values represented by linear lines interconnecting a coordinate point A (1.1, 0.90), a coordinate point B (1.5, 0.55), and a coordinate point C (1.8, 0.55).
  • the high-strength heat resisting cast steel has good weldability with such properties that creep rupture strength at 620°C and 10 5 hours is 98 MPa or more, and impact absorbed energy at room temperature is 29.4 J or more.
  • the creep rupture strength at 620°C and 10 5 hours is 108 MPa or more, and the impact absorbed energy at room temperature is 31.4 J or more.
  • the method of producing the high-strength heat resisting cast steel comprises the steps of smelting, in an electric furnace, raw materials with the above-described composition; deaerating the smelted materials by vacuum ladle refining; and casting the deaerated materials into a sand mold.
  • the method of producing the high-strength heat resisting cast steel comprises the steps of annealing, at 1000 - 1150°C, the cast steel obtained after the above-described casting step; performing thermal normalizing of the annealed steel through steps of heating to 1000 - 1100°C and subsequent quick cooling; and performing two successive stages of heat treatment, i.e., primary tempering at 550 - 750°C and secondary tempering at 670 - 770°C.
  • the steam turbine casing, the main steam valve and its casing, and the steam control valve and its casing, according to the present invention, are produced by using the high-strength heat resisting cast steel which has the above-described composition and is produced by the above-described method.
  • the steam turbine power plant according to the present invention is constituted by the steam turbine casing, the main steam valve, and the steam control valve.
  • C is an element that is required to be 0.06% or more to obtain high tensile length.
  • the C content exceeds 0.16%, the metal structure becomes unstable when exposed to high temperatures for a long time, thus resulting in reduction of long-time creep rupture strength. For that reason, the C content is limited to 0.06 - 0.16%.
  • a preferable range is 0.08 - 0.14% and a more preferable range is 0.09-0.12%.
  • Mn is added as a deoxidizer. By adding 0.1% of Mn, the effect of the deoxidizer is achieved. Addition of Mn in excess of 1% reduces the creep rupture strength. In particular, a preferable range is 0.3 - 0.8% and a more preferable range is 0.4 - 0.7%.
  • Si is also added as a deoxidizer. Addition of Si can be reduced by employing the steel-making technology based on, e.g., the vacuum carbon deoxidation method, but Si is required to be added 0.1% or more. Also, because Si generates the harmful ⁇ ferrite structure, the addition of Si in excess of 1% must be avoided. Reducing the Si content has the effect of preventing generation of the harmful ⁇ ferrite structure. Accordingly, when Si is added, the Si content is required to be held 1% or less. In particular, a preferable range is 0.6% or less and a more preferable range is 0.2 - 0.6%.
  • Cr is effective in improving high-temperature strength and high-temperature oxidation.
  • addition of Cr in excess of 11% causes the generation of the harmful ⁇ ferrite structure, and excessive addition of Cr causes reduction of toughness.
  • the Cr content is less than 10%, oxidation resistance against high-temperature and high-pressure steam is not sufficient.
  • the Cr range is 10.0 - 11.0%.
  • Ni is an element that suppresses generation of ⁇ ferrite and gives toughness. Therefore, the Ni content is required to be 0.1% at minimum. However, addition of Ni in excess of 1% reduces the creep rupture strength at temperatures of 620°C or above. For that reason, the Ni content is limited to 0.1 - 1.0%. In particular, a preferable range is 0.2 - 0.8% and a more preferable range is 0.3 - 0.7%.
  • W is effective in noticeably increasing the high-temperature and long-time strength. If the W content is less than 1.9%, the effect of increasing the strength is not sufficient as heat resisting cast steel when the steel is used at temperatures of 620°C or above. On the other hand, if the W content exceeds 3.0%, toughness is reduced. In particular, a preferable range is 1.95 - 2.7% and a more preferable range is 2.0 - 2.5%.
  • Mo is added to increase the high-temperature strength.
  • W is contained in excess of 1.9% as in the cast steel of the present invention
  • addition of Mo in excess of 0,6% reduces toughness and fatigue strength. Accordingly, the Mo content is limited to 0,6% or less. Thus the Mo range is 0.2 - 0.6%.
  • V is effective in increasing the creep rupture strength. If the V content is less than 0.05%, the reslting effect is not sufficient. Conversely, if the V content exceeds 0.3%, ⁇ ferrite is generated to reduce the fatigue strength. In particular, a preferable range is 0.10 - 0.25% and a more preferable range is 0.12 - 0.23%.
  • Nb is a very effective element to increase the high-temperature strength.
  • excessive addition of Nb generates coarse eutectic NB carbides, particularly in a large-sized steel ingot, thus causing precipitation of ⁇ ferrite that reduces the high-temperature strength and the fatigue strength.
  • the Nb content is required to be held less than 0.15%.
  • the Nb content is less than 0.01%, the resulting effect is not sufficient.
  • a preferable range is 0.02 - 0.12% and a more preferable range is 0.04 - 0.10%.
  • Ta and Zr are effective in increasing low-temperature toughness. A sufficient effect is obtained by adding 0.15% or less of Ta and 0.1% or less of Zr solely or in combination. When Ta is added 0.1% or more, addition of Nb can be omitted.
  • Co noticeably increases the high-temperature strength when added 0.1% or more. Such effect is presumably attributable to the interaction with W. In other words, that effect is a phenomenon specific to the alloy of the present invention which contains 1.9% or more of W. On the other hand, excessive addition of Co over 2% reduces structure stability at high temperatures and hence reduces the creep rupture strength. Therefore, the Co content is limited to 0.1 - 2%. In particular, a preferable range is 0.1 - 1.6% and a more preferable range is 0.2 - 1.2%.
  • N has the actions of not only precipitating a nitride of V, but also increasing the high-temperature strength in the solid solution state based on the IS effect (interaction between an interstitial solid solution element and a substitutive solid solution element) in cooperation with Mo and W. Therefore, N is required to be added 0.01% at minimum. However, addition of N in excess of 0.08% reduces ductility. For that reason, the N content is limited to 0.01 - 0.08%. In particular, a preferable range is 0.015 - 0.075% and a more preferable range is 0.015 - 0.06%.
  • Al is added 0.0005% or more as a deoxidizer and a crystal grain reducing agent (refiner).
  • Al is a strong nitride-forming element and fixates N that effectively acts to prevent creep.
  • addition of Al in excess of 0.03% reduces the long-time creep strength at 10 4 hours or more in a high temperature range.
  • Al promotes precipitation of the Laves phase in the form of a brittle intermetallic compound made of mainly W, thus causing precipitation of the Laves phase at the crystal grain boundary and reduction of the creep rupture strength at the longer-time side.
  • the Laves phase is continuously precipitated along the crystal grain boundary. Accordingly, an upper limit of the Al content is set to 0.03%.
  • the Al range is 0.0005- 0.03 %.
  • B is effective in increasing the high-temperature strength by the action of strengthening the crystal grain boundary and the action of causing solid solution in M 23 C 6 to thereby prevent aggregation of M 23 C 6 -type carbides into coarser grains. That effect is obtained by adding 0.0005% of B at minimum. However, addition of B in excess of 0.01% impedes weldability. For that reason, the B content is limited to 0.0005 - 0.01%. In particular, a preferable range is 0.001 - 0.008% and a more preferable range is 0.002 - 0.007%.
  • the O content in excess of 0.010% reduces the high-temperature strength and toughness values, it should be kept 0.010% or less.
  • the O range is 0.004 - 0.010 wt.
  • At least one of Re, Nd and Sr is added as explained below.
  • Re noticeably increases the high-temperature strength by strengthening with the solid solution. Because excessive addition promotes embrittlement, Re is added 1.5% or less. In consideration of Re being a rare element, the preferable range is 1.5% or less and a preferable range is 1.2% or less from the practical point of view.
  • Nd increases the high-temperature strength by forming carbo-nitrides. Nd exhibits an effect even when added in small amount, and excessive addition promotes embrittlement. Therefore, Nd is added 0.5% or less. In consideration of Nd being a rare element, its range is 0.5% or less and a preferable range is 0.3% or less from the practical point of view.
  • Sr strengthens the old austenite grain boundary and increases the low-temperature toughness and strength, thus increasing especially the creep rupture strength.
  • excessive addition promotes formation of carbo-nitrides at the grain boundary and makes the grain boundary more brittle, which leads to reduction of the toughness and strength. Therefore, Sr is added 1.0% or less.
  • a preferable range is 0.8% or less and a more preferable range is 0.5% or less from the practical point of view.
  • the heat resisting cast steel preferably has the uniform tempered martensite structure.
  • the Cr equivalent expressed by the following formula (1) must be held 10 or less.
  • the Cr equivalent must be held 4 or more because the high-temperature creep rupture strength is reduced if the Cr equivalent is too low.
  • P and S are each preferably held 0.020% or less from the viewpoint of increasing the low-temperature toughness.
  • a preferable range of P is 0.015% or less
  • a preferable range of S is 0.015% or less
  • a more preferable range of P is 0.010% or less
  • a more preferable range of S is 0.010% or less.
  • Sb is preferably held 0.0015% or less
  • Sn is preferably held 0.01% or less
  • As is preferably held 0.02% or less from the viewpoint of the current level of the steel-making technology. More preferably, Sb is held 0.0010% or less, Sn is held 0.005% or less, and As is held 0.01% or less.
  • the casing material is required to have the creep rupture strength at 620°C and 10 5 hours of 98 MPa or more. Also, because thermal stress is caused at a relatively low material temperature when the turbine is started, the casing material is required to have the impact absorbed energy at room temperature of 29.4 J or more from the viewpoint of preventing brittle fracture. To ensure higher reliability, preferably, the creep rupture strength at 620°C and 10 5 hours is 108 MPa or more, and the impact absorbed energy at room temperature is 31.4 J or more.
  • the steel ingot is a large-sized mass having weight of about 50 tons, and the highly developed steel-making technology is required to produce a steel ingot including less defects.
  • the high-strength heat resisting cast steel according to the present invention can be produced in the satisfactory form through the steps of smelting, in an electric furnace, alloy raw materials with the objective composition, deaerating the smelted materials by vacuum ladle refining, and casting the deaerated materials into a sand mold. By sufficiently refining and deoxidizing the materials before the casting step, the cast steel can be obtained with less casting defects such as shrinkage. The above point is similarly applied to the production of the main steam valve and the steam control valve.
  • a large-sized steel ingot adapted for, e.g., the steam turbine casing, which can be used in steam at 620°C or above, through the steps of annealing, at 1000 - 1150°C, the heat resisting cast steel obtained as described above; performing thermal normalizing of the annealed steel through steps of heating to 1000 - 1100°C and subsequent quick cooling, and successively performing primary tempering at 550 - 750°C and secondary tempering at 670 - 770°C. If the annealing temperature and the normalizing temperature are 1000°C or below, carbo-nitrides cannot be obtained in the state of sufficient solid solution. Conversely, if those temperatures are too high, coarser crystal grains are caused.
  • the steam turbine casing capable of being used in steam at 620°C or above is realized in which the creep rupture strength at 620°C and 10 5 hours is 98 MPa or more, and the impact absorbed energy at room temperature is 29.4 J or more.
  • the present invention can provide the ferrite-base heat resisting cast steel having high creep rupture strength at 620°C and high toughness at room temperature, which can be used for casings of an ultra super critical (USC) pressure steam turbine operated at temperatures until 650°C.
  • USC ultra super critical
  • the heat resisting cast steel of the present invention for the casings of the USC pressure steam turbine operated at temperatures until 650°C instead of the austenite heat resisting cast steel, those casings can be produced in accordance with the same design concept as that in the past. Further, since the heat resisting cast steel of the present invention has a smaller thermal expansion coefficient than the austenite heat resisting cast steel, other advantages are obtained in that quick start of the steam turbine can be more easily performed and the casings are less susceptible to damages caused by thermal fatigue.
  • Table 1 shows chemical composition (% by mass) of the heat resisting cast steel according to the present invention. Assuming a thick wall portion of a large-sized casing, a sample was prepared by smelting 200 kg of raw materials in a high-frequency induction melting furnace, and casting the smelted materials into a sand mold with a thickness of 200 mm, a width of 380 mm and a height of 440 mm at maximum, thereby obtaining a cast ingot.
  • samples No. 1-13 represent the steel of the present invention
  • samples No. 30-35 represent the known comparative steels.
  • any of the samples was subjected to annealing of 1050°C ⁇ 8 hours with subsequent furnace cooling, thermal normalizing performed through steps of heating and holding of 1050°C ⁇ 8 hours and subsequent air cooling, primary tempering through steps of heating and holding of 680°C ⁇ 7 hours and subsequent air cooling, and secondary tempering through steps of heating and holding of 710°C ⁇ 7 hours and subsequent air cooling.
  • Table 2 shows the test results of tensile strength at room temperature, V-notch Charpy impact absorbed energy at 20°C, creep rupture strength at 620°C ⁇ 10 5 hours, and weld cracks.
  • the creep rupture strength and the impact absorbed energy sufficiently satisfy the above-described characteristics (i.e., the creep rupture strength at 620°C ⁇ 10 5 hours ⁇ 98 MPa and the impact absorbed energy at 20°C ⁇ 29.4 J) which are required for the high-temperature and high-pressure turbine casing used at temperatures until 650°C.
  • the ferrite-base heat resisting cast steel having high creep rupture strength at 620°C and high toughness at room temperature can be obtained, and it can be suitably used for the casings of the ultra super critical (USC) pressure steam turbine operated at temperatures until 650°C, the main steam valve, and the steam control valve.
  • USC ultra super critical
  • the heat resisting cast steel of the present invention for the casings of the USC pressure steam turbine operated at temperatures until 650°C, the main steam valve, and the steam control valve instead of the austenite heat resisting cast steel, those casings can be produced in accordance with the same design concept as that in the past. Further, since the heat resisting cast steel of the present invention has a smaller thermal expansion coefficient than the austenite heat resisting cast steel, other advantages are obtained in that quick start of the steam turbine can be more easily performed and the casings are less susceptible to damages caused by thermal fatigue.
  • Fig. 13 is a cross-sectional view showing the structure of a high-pressure steam turbine using the high-strength heat resisting cast steel according to the present invention.
  • Fig. 14 is a cross-sectional view showing the structure of an intermediate-pressure steam turbine using the high-strength heat resisting cast steel according to the present invention.
  • the high-pressure steam turbine includes an inner casing 18, an outer casing 19 surrounding the inner casing 18, and a high-pressure rotor shaft 20 provided with high-pressure rotor blades 16 implanted to it and disposed inside those casings.
  • the intermediate-pressure steam turbine includes an inner casing 21, an outer casing 22 surrounding the inner casing 21, and an intermediate-pressure rotor shaft 24 provided with intermediate-pressure rotor blades 17 implanted to it and disposed inside those casings.
  • High-temperature and high-pressure steam obtained by a boiler passes through a main steam pipe and flows into a main steam inlet 28 through a flange and elbow 25 constituting a main steam section.
  • the steam is then introduced to the rotor blade in the double-flow first stage through a nozzle box 38.
  • Stator nozzles are disposed corresponding to the rotor blades.
  • a steam turbine power plant is constituted by the high-pressure steam turbine (HP) and the intermediate-pressure steam turbine (IP) which are connected in tandem.
  • HP has the double-flow first stage and includes eight stages in each side.
  • Stator nozzles are disposed corresponding to the rotor blades in both the sides.
  • Each rotor blade is of the saddle-like dovetailed type and has double tenons.
  • the IP is used to rotate a generator in cooperation with the HP by utilizing steam obtained by heating the steam, which is exhausted from the HP, to 625°C again by a reheater, and it is rotated at rotation speed of 3000 rpm.
  • the IP has an intermediate-pressure inner compartment (casing) 21 and an intermediate-pressure outer compartment (casing) 22, and further includes stator nozzle corresponding to the intermediate-pressure rotor blades 17.
  • the intermediate-pressure rotor blades 17 are constituted with two flow sections each including six stages and are arranged in substantially bilateral symmetry in the longitudinal direction of the intermediate-pressure rotor shaft 24.
  • the outer casings 19 and 22, the inner casings 18 and 21, and respective casings of a main steam valve and a steam control valve were each made of the sample No. 4 cast steel in Table 1 described above in connection with the first embodiment.
  • the inner casings were each produced through the steps of smelting, in an electric furnace, 50 tons of alloy raw materials with the objective composition, deaerating the smelted materials by vacuum ladle refining, and casting the deaerated materials into a sand mold.
  • the obtained trial cast steel was successively subjected to annealing of 1050°C x 10 hours with subsequent furnace cooling, thermal normalizing performed through steps of heating and holding of 1050°C ⁇ 10 hours and subsequent blast air cooling, primary tempering of 570°C ⁇ 12 hours, and secondary tempering of 730°C ⁇ 12 hours.
  • the trial casing satisfied the characteristics (i.e., the creep rupture strength at 620°C and 10 5 hours ⁇ 98 MPa and the impact absorbed energy at room temperature ⁇ 29.4 J) required for the casing of the high-temperature and the high-pressure turbine operated at 620°C and 25 MPa, and it caused no cracks in the above-described weld cracking test.
  • the ferrite-base heat resisting cast steel having high creep rupture strength at 620°C and high toughness at room temperature can be obtained, and it can be suitably used for, e.g., the casings of the ultra super critical (USC) pressure steam turbine operated at temperatures until 650°C.
  • USC ultra super critical
  • the heat resisting cast steel of the present invention for the casings of the USC pressure steam turbine operated at temperatures until 650°C instead of the austenite heat resisting cast steel, those casings can be produced in accordance with the same design concept as that in the past. Further, since the heat resisting cast steel of the present invention has a smaller thermal expansion coefficient than the austenite heat resisting cast steel, other advantages are obtained in that quick start of the steam turbine can be more easily performed and the casings are less susceptible to damages caused by thermal fatigue.
  • the steam turbine power plant of this embodiment further includes two low-pressure steam turbines (LPs) which are connected in tandem and have substantially the same structure.
  • LP low-pressure steam turbines
  • last-stage and other rotor blades are disposed in eight stages in each of the left and right sides and are arranged in substantially bilateral symmetry.
  • Stator nozzles are disposed corresponding to the rotor blades.
  • a low-pressure rotor shaft is made of forged steel having the fully tempered bainite structure of a super-clean material containing 3.75% of Ni, 1.75% of Cr, 0.4% of Mo, 0.15% of V, 0.25% of C, 0.05% of Si, and 0.10% of Mn, the balance being Fe.
  • Any of the rotor blades and the stator nozzles in stages other than the last stage is made of 12%-Cr steel containing 0.1% of Mo.
  • the last-stage rotor blade has an airfoil height of 43 inches.
  • An airfoil of the long blade having the airfoil height of 43 inches, against which high-speed steam impinges, is coated with an erosion shield formed by joining a stellite sheet made of a Co-base alloy by welding in order to prevent erosion caused by water droplets in the steam.
  • the 43-inch long blade is produced through a series of steps of smelting by the electroslag remelting process, forging, and heat treatment.
  • the long blade is made of martensite steel containing 0.08 - 0.18% by mass of C, 0.25% or less of Si, 0.90% or less of Mn, 8.0 - 13.0% of Cr, 2 - 3% of Ni, 1.5 - 3.0% of Mo, 0.05 - 0.35% of V, 0.02 - 0.20% of one or more of Nb and Ta in total, and 0.02 - 0.10% of N.
  • the long blade exhibits the tensile strength at room temperature of 120 kgf/mm 2 or more and has the fully tempered martensite structure.
  • the mechanical properties of the 43-inch long blade more preferably, the tensile strength is 128.5 kgf/mm 2 or more and the V-notch Charpy impact value at 20°C is 4 kgf-m/cm 2 or more.
  • the high-temperature and high-pressure steam turbine power plant comprises mainly a coal firing boiler, one HP, one IP, two LPs, a condenser, a condensing pump, a low-pressure feedwater heater system, a deaerator, a booster pump, a feedwater pump, and a high-pressure feedwater heater system. More specifically, ultra high-temperature and high-pressure steam generated in the boiler enters the HP in which motive power is produced. Then, the steam is reheated by the boiler and enters the IP in which motive power is produced. The steam exhausted from the IP enters the LP in which motive power is produced, followed by being condensed in the condenser.
  • the condensed water is sent to the low-pressure feedwater heater system and the deaerator by the condensing pump.
  • the feedwater deaerated in the deaerator is sent to the high-pressure feedwater heater system by the booster pump and the condensing pump.
  • the feedwater is returned to the boiler.
  • the feedwater is converted to high-temperature and high-pressure steam through an economizer, an evaporator and a superheater.
  • a tandem compound power plant may be constituted in which one HP, one IP, and one or two LPs are connected in tandem to rotate one generator, each of HP, IP and LP having similar structures to those described above.
  • the steam turbine power plant can be obtained which has high thermal efficiency and is suitable for use with, e.g., the steam turbine casings having the long-time creep rupture strength and toughness which are required under steam temperature condition of 620 - 650°C.
  • the heat resisting cast steel of the present invention for the casings of the USC pressure steam turbine operated at temperatures until 650°C, the main steam valve, and the steam control valve instead of the austenite heat resisting cast steel, those casings can be produced in accordance with the same design concept as that in the past. Further, since the heat resisting cast steel of the present invention has a smaller thermal expansion coefficient than the austenite heat resisting cast steel, other advantages are obtained in that quick start of the steam turbine can be more easily performed and the casings are less susceptible to damages caused by thermal fatigue.
  • Fig. 15 is a cross-sectional view showing the structure of a high- and intermediate-pressure integral steam turbine used in a steam turbine power plant with steam temperature of 620°C and output capacity of 600 MW.
  • the power plant of this third embodiment is of the tandem compound double-flow type, and the last-stage blade height in the LP is 43 inches.
  • a rotation speed of 3000 rpm is obtained by the high- and intermediate-pressure integral steam turbine (HP-IP) and one LP (C) or two LPs (D).
  • Components used in a high-temperature region are each made of main materials shown in Table 1, which constitute the steel of the present invention.
  • the steam temperature and pressure in the high-pressure section (HP) are 600°C and 250 kgf/cm 2 .
  • the steam temperature is heated to 600°C by a reheater and operation is performed at pressure of 45 - 65 kgf/cm 2 .
  • Steam having temperature of 400°C enters the low-pressure section (LP) and is sent to a condenser under vacuum of 722 mmHg at 100°C or below.
  • the high-pressure side steam turbine includes an inner casing 18 and an outer casing 19 surrounding the inner casing 18, whereas the intermediate-pressure steam turbine includes an inner casing 21 and an outer casing 22 surrounding the inner casing 21.
  • a high- and intermediate-pressure integral rotor shaft 23 provided with high-pressure rotor blades 16 and intermediate-pressure rotor blades 17 implanted to the rotor shaft is disposed inside those casings.
  • the high-pressure and high-temperature steam obtained by the boiler passes through a main steam pipe and flows into a main steam inlet 28 through a flange and elbow 25 constituting a main steam section.
  • the steam is then introduced to the rotor blade in the first stage through a nozzle box 38.
  • the rotor blades are disposed in eight stages on the high-pressure side in substantially a left half in Fig. 15 and six stages on the intermediate-pressure side in substantially a right half in Fig. 15 .
  • Stator nozzles are disposed corresponding to the rotor blades.
  • Each rotor blade is of the saddle- or nearly ⁇ -like dovetailed type and has double tenons.
  • the outer casings 19 and 22 and the inner casings 18 and 21, and respective casings of a main steam valve and a steam control valve were each made of the sample No. 4 cast steel in Table 1 described above in connection with the first embodiment.
  • those casings were each produced through the steps of smelting, in an electric furnace, 50 tons of alloy raw materials with the objective composition, deaerating the smelted materials by vacuum ladle refining, and casting the deaerated materials into a sand mold.
  • those casings also had the fully tempered martensite structure.
  • the trial casing satisfied the characteristics (i.e., the creep rupture strength at 620°C and 10 5 hours ⁇ 98 MPa and the impact absorbed energy at room temperature ⁇ 29.4 J) required for the casing of the high-temperature and the high-pressure turbine operated at 620°C and 25 MPa, and it caused no cracks in the above-described weld cracking test.
  • the ferrite-base heat resisting cast steel having high creep rupture strength at 620°C and high toughness at room temperature can be obtained, and it can be suitably used for, e.g., the casings of the ultra super critical (USC) pressure steam turbine operated at temperatures until 650°C.
  • USC ultra super critical
  • the heat resisting cast steel of the present invention for the casings of the USC pressure steam turbine operated at temperatures until 650°C instead of the austenite heat resisting cast steel, those casings can be produced in accordance with the same design concept as that in the past. Further, since the heat resisting cast steel of the present invention has a smaller thermal expansion coefficient than the austenite heat resisting cast steel, other advantages are obtained in that quick start of the steam turbine can be more easily performed and the casings are less susceptible to damages caused by thermal fatigue.
  • one or two low-pressure steam turbines are connected in tandem and have substantially the same structure as that in the second embodiment.
  • last-stage and other rotor blades are disposed in eight stages in each of the left and right sides and are arranged in substantially bilateral symmetry, thus enabling power generation with an output capacity of 1050 MW.
  • the last-stage rotor blade has an airfoil height of 43 inches and is made of the 12%-Cr steel as in the above-described case.
  • a low-pressure rotor shaft, the rotor blades and the stator nozzles in stages other than the last stage, and inner and outer casings are each produced in a similar manner.
  • An airfoil of the long blade having the airfoil height of 43 inches, against which high-speed steam impinges, is coated with an erosion shield formed by joining a stellite sheet made of a Co-base alloy by welding in order to prevent erosion caused by water droplets in the steam.
  • the 43-inch long blade is produced, as in the second embodiment, through a series of steps of smelting by the electroslag remelting process, forging, and heat treatment.
  • the long blade has the fully tempered martensite structure exhibiting the tensile strength at room temperature of 120 kgf/mm 2 or more, preferably 128.5 kgf/mm 2 or more, and the V-notch Charpy impact value at 20°C of 4 kgf-m/cm 2 or more.
  • the steam turbine power plant can be obtained which has high thermal efficiency and is suitable for use with, e.g., the steam turbine casings having the long-time creep rupture strength and toughness which are required under steam temperature condition of 620 - 650°C.
  • Fig. 16 is a cross-sectional view of a main steam valve and a steam control valve used in a steam turbine power plant, which are formed in an integral structure.
  • the main steam sent from the boiler to the high-pressure steam turbine and the high- and intermediate-pressure integral steam turbine in the steam turbine power plant of the second or third embodiment is supplied to a main steam valve 32 through a main steam inlet 34 and the amount of steam supplied through a steam outlet 35 is controlled by a steam control valve 33.
  • a casing of each of the main steam valve and the steam control valve was made of the sample No. 4 cast steel in Table 1 described above in connection with the first embodiment and was produced through the steps of smelting, in an electric furnace, alloy raw materials with the objective composition, deaerating the smelted materials by vacuum ladle refining, and casting the deaerated materials into a sand mold.
  • the obtained trial casing was subjected to heat treatment and a weld cracking test in a similar manner to those in the second embodiment.
  • the trial casing satisfied the characteristics (i.e., the creep rupture strength at 620°C and 10 5 hours ⁇ 98 MPa and the impact absorbed energy at room temperature ⁇ 29.4 J) required for the casing of the high-temperature and the high-pressure turbine operated at 620°C and 25 MPa, and it caused no cracks in the above-described weld cracking test.
  • the ferrite-base heat resisting cast steel having high creep rupture strength at 620°C and high toughness at room temperature can be obtained, and it can be suitably used for the respective casings of the main steam valve and the steam control valve in the ultra super critical (USC) pressure steam turbine operated at temperatures until 650°C.
  • the fourth embodiment can also provide similar advantages to those in the above-described embodiments.
  • Features, components and specific details of the structures of the above-described embodiments may be exchanged or combined within the scope of the present claims.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Control Of Turbines (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Claims (9)

  1. Acier coulé à haute résistance résistant à la chaleur, contenant 0,06 à 0,16 % en masse de C, 0,1 à 1 % de Si, 0,1 à 1 % de Mn, 10,0 à 11,0% de Cr, 0,1 à 1,0% % de Ni, 0,2 à 0,6% de Mo, 2,0 à 2,5% de W, 0,05 à 0,3% de V, 0,01 à 0,15 % d'un ou plusieurs parmi Nb, Ta et Zr au total, 0,2 à 1,2 % de Co, 0,01 à 0,08 % de N, 0,0005 à 0,01 % de B, 0,0005 à 0,03 % d'Al, et 0,004 à 0,01 % d'O, ainsi qu'au moins l'un parmi 1,5 % en masse ou moins de Re, 0,5 % ou moins de Nd, et 1,0 % ou moins de Sr, le reste étant du Fe et des impuretés inévitables, et dans lequel, dans des coordonnées orthogonales exprimées par la relation entre [W/(Mo + 0,5W)] et (Co/W), les valeurs de [W/(Mo + 0,5W)] et (Co/W) ne sont pas supérieures aux valeurs représentées par des lignes linéaires interconnectant un point de coordonnées A (1,1, 0,90), un point de coordonnées B (1,5, 0,55) et un point de coordonnées C (1,8, 0,55).
  2. Acier coulé à haute résistance résistant à la chaleur selon la revendication 1, dans lequel la résistance à la rupture en fluage à 620°C et 105 heures est de 98 MPa ou plus, et l'énergie absorbée de choc à la température ambiante est de 29,4 J ou plus.
  3. Procédé pour produire un acier coulé à haute résistance résistant à la chaleur, lequel procédé comprend les étapes consistant à :
    fondre, dans un four électrique, des matières premières ayant une composition contenant 0,06 à 0,16 % en masse de C, 0,1 à 1 % de Si, 0,1 à 1 % de Mn, 10,0 à 11,0 % de Cr, 0,1 à 1,0 % de Ni, 0,2 à 0,6 % de Mo, 2,0 à 2,5 % de W, 0,05 à 0,3 % de V, 0,01 à 0,15 % d'un ou plusieurs parmi Nb, Ta et Zr au total, 0,2 à 1,2 % de Co, 0,01 à 0,08 % de N, et 0,0005 à 0,01 % de B, 0,0005 à 0,03 % en masse d'Al, et 0,004 à 0,01 % d'O, ainsi qu'au moins l'un parmi 1,5 % en masse ou moins de Re, 0,5 % ou moins de Nd, et 1,0 % ou moins de Sr, le reste étant du Fe et des impuretés inévitables ;
    désaérer les matériaux fondus par raffinage en poche sous vide ; et
    couler les matériaux désaérés dans un moule en sable.
  4. Procédé pour produire un acier coulé à haute résistance résistant à la chaleur selon la revendication 1, lequel procédé comprend en outre les étapes consistant à :
    recuire, à 1000-1150°C, l'acier coulé ayant la composition selon la revendication 1 ;
    réaliser une normalisation thermique de l'acier recuit par l'intermédiaire d'étapes de chauffage à 1000-1100°C et de refroidissement rapide subséquent ; et
    réaliser successivement une trempe primaire à 550-750°C et une trempe secondaire à 670-770°C.
  5. Turbine à vapeur comprenant un arbre de rotor contenant des ailettes implantées, un carter intérieur contenant des buses de stator implantées correspondant auxdites ailettes et couvrant ledit arbre de rotor contenant lesdites ailettes implantées, et un carter extérieur recouvrant ledit carter intérieur, dans laquelle ledit carter intérieur est constitué de l'acier coulé à haute résistance résistant à la chaleur selon la revendication 1.
  6. Vanne de vapeur principale pour contrôler la fourniture et l'arrêt de la vapeur principale obtenue par une chaudière en regard d'une turbine à vapeur, dans laquelle un carter de ladite vanne de vapeur principale est fait en l'acier coulé à haute résistance résistant à la chaleur selon l'une quelconque des revendications 1 et 2.
  7. Vanne de contrôle de vapeur pour contrôler la quantité fournie de vapeur principale obtenue par une chaudière par l'intermédiaire d'une vanne de vapeur principale qui contrôle la fourniture et l'arrêt de la vapeur principale en regard d'une turbine à vapeur, dans laquelle un carter de ladite vanne de contrôle de vapeur est fait en l'acier coulé à haute résistance résistant à la chaleur selon l'une quelconque des revendications 1 et 2.
  8. Centrale à turbine à vapeur comprenant l'un quelconque parmi un ensemble d'une turbine à vapeur haute pression, d'une turbine à vapeur sous pression intermédiaire, et de deux turbines à vapeur basse pression connectées en tandem, et un ensemble d'une turbine à vapeur intégrale sous pression élevée et intermédiaire et d'une turbine à vapeur basse pression, dans laquelle au moins l'une parmi ladite turbine à vapeur haute pression, ladite turbine à vapeur sous pression intermédiaire, et la turbine à vapeur intégrale sous pression élevée et intermédiaire, est constituée de la turbine à vapeur selon la revendication 5.
  9. Centrale à turbine à vapeur comprenant l'un quelconque parmi un ensemble d'une turbine à vapeur haute pression, d'une turbine à vapeur sous pression intermédiaire, et de deux turbines à vapeur basse pression connectées en tandem, et un ensemble d'une turbine à vapeur intégrale sous pression élevée et intermédiaire et d'une turbine à vapeur basse pression, ladite centrale comprenant en outre une vanne de vapeur principale pour contrôler la fourniture et l'arrêt de vapeur principale obtenue par une chaudière et une vanne de contrôle de vapeur pour contrôler la quantité fournie de la vapeur principale par l'intermédiaire d'une vanne de vapeur principale, dans laquelle au moins l'une parmi ladite vanne de vapeur principale et ladite vanne de contrôle de vapeur est constituée de la vanne de vapeur principale et de la vanne de contrôle de vapeur selon les revendications 6 et 7.
EP06020264A 2005-09-29 2006-09-27 Acier coulé à haute résistance mécanique et résistant à la chaleur ainsi que son procédé de fabrication et ses applications Expired - Fee Related EP1770182B1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2005283199A JP4542491B2 (ja) 2005-09-29 2005-09-29 高強度耐熱鋳鋼とその製造方法及びそれを用いた用途

Publications (2)

Publication Number Publication Date
EP1770182A1 EP1770182A1 (fr) 2007-04-04
EP1770182B1 true EP1770182B1 (fr) 2011-12-14

Family

ID=37496517

Family Applications (1)

Application Number Title Priority Date Filing Date
EP06020264A Expired - Fee Related EP1770182B1 (fr) 2005-09-29 2006-09-27 Acier coulé à haute résistance mécanique et résistant à la chaleur ainsi que son procédé de fabrication et ses applications

Country Status (3)

Country Link
US (2) US20070071599A1 (fr)
EP (1) EP1770182B1 (fr)
JP (1) JP4542491B2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3263732B1 (fr) * 2015-02-27 2022-04-13 National Institute for Materials Science Acier ferritique résistant à la chaleur et son procédé de fabrication

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101514433A (zh) * 2007-03-16 2009-08-26 株式会社神户制钢所 低温冲击特性优异的汽车用高强度电阻焊钢管及其制造方法
JP5022887B2 (ja) * 2007-12-25 2012-09-12 株式会社東芝 蒸気弁装置および蒸気タービンプラント
US8943836B2 (en) * 2009-07-10 2015-02-03 Nrg Energy, Inc. Combined cycle power plant
JP4982539B2 (ja) 2009-09-04 2012-07-25 株式会社日立製作所 Ｎｉ基合金、Ｎｉ基鋳造合金、蒸気タービン用高温部品及び蒸気タービン車室
JP5562825B2 (ja) * 2010-12-28 2014-07-30 株式会社東芝 耐熱鋳鋼、耐熱鋳鋼の製造方法、蒸気タービンの鋳造部品および蒸気タービンの鋳造部品の製造方法
JP2012219682A (ja) * 2011-04-07 2012-11-12 Hitachi Ltd 蒸気タービン用ロータシャフトと、それを用いた蒸気タービン
CN102518869B (zh) * 2011-12-30 2013-11-06 中国人民解放军国防科学技术大学 截止阀
CN102829195A (zh) * 2012-09-05 2012-12-19 张丽智 通配紧凑型锻钢自密封截止阀
CN103256394A (zh) * 2013-05-17 2013-08-21 江苏星河阀门有限公司 阀杆不旋转仪表截止阀
CN104046919B (zh) * 2014-07-09 2015-12-30 南京赛达机械制造有限公司 一种高寿命汽轮机叶片及其生产工艺
JP6334384B2 (ja) 2014-12-17 2018-05-30 三菱日立パワーシステムズ株式会社 蒸気タービンロータ、該蒸気タービンロータを用いた蒸気タービン、および該蒸気タービンを用いた火力発電プラント
CN104831160B (zh) * 2015-03-26 2016-09-28 哈尔滨汽轮机厂有限责任公司 用于630℃超超临界汽轮机叶片的含Re钢材料及其制造方法
JP6991755B2 (ja) * 2017-07-03 2022-01-13 株式会社東芝 蒸気タービンのノズル板の製造方法
DE102017211295A1 (de) * 2017-07-03 2019-01-03 Siemens Aktiengesellschaft Dampfturbine und Verfahren zum Betreiben derselben
CN112626413A (zh) * 2020-11-28 2021-04-09 四川维珍高新材料有限公司 一种航空用机匣类产品及其生产工艺
WO2023286204A1 (fr) 2021-07-14 2023-01-19 日本製鉄株式会社 Acier ferritique résistant à la chaleur
CN116065096B (zh) * 2023-03-05 2023-08-04 襄阳金耐特机械股份有限公司 一种铁素体耐热铸钢

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6152353A (ja) * 1984-08-23 1986-03-15 Toshiba Corp 高クロム耐熱鋳鋼
US4735771A (en) * 1986-12-03 1988-04-05 Chrysler Motors Corporation Method of preparing oxidation resistant iron base alloy compositions
JPH0759740B2 (ja) * 1989-05-23 1995-06-28 新日本製鐵株式会社 靭性およびクリープ強度に優れたフェライト系耐熱鋼
JPH05263196A (ja) * 1992-03-19 1993-10-12 Nippon Steel Corp 高温強度ならびに靱性に優れたフェライト系耐熱鋼
JPH0770713A (ja) * 1993-07-07 1995-03-14 Japan Steel Works Ltd:The 耐熱鋳鋼
JPH0734202A (ja) * 1993-07-23 1995-02-03 Toshiba Corp 蒸気タービン用ロータ
JPH07286246A (ja) * 1994-04-18 1995-10-31 Nippon Steel Corp 高強度フェライト系耐熱鋼
JPH07286247A (ja) * 1994-04-18 1995-10-31 Nippon Steel Corp 高強度フェライト系耐熱鋼
JP3723924B2 (ja) * 1995-04-03 2005-12-07 株式会社日本製鋼所 耐熱鋳鋼およびその製造方法
JPH0959747A (ja) * 1995-08-25 1997-03-04 Hitachi Ltd 高強度耐熱鋳鋼，蒸気タービンケーシング，蒸気タービン発電プラント及び蒸気タービン
JP3368413B2 (ja) * 1996-04-25 2003-01-20 新日本製鐵株式会社 高Ｃｒフェライト系耐熱鋼の製造方法
JPH1136038A (ja) * 1997-07-16 1999-02-09 Mitsubishi Heavy Ind Ltd 耐熱鋳鋼
JPH1161342A (ja) * 1997-08-08 1999-03-05 Mitsubishi Heavy Ind Ltd 高Ｃｒフェライト鋼
JP2001152293A (ja) * 1999-11-22 2001-06-05 Sumitomo Metal Ind Ltd 高Ｃｒフェライト系耐熱鋼
JP3508667B2 (ja) * 2000-01-13 2004-03-22 住友金属工業株式会社 高温強度に優れた高Ｃｒフェライト系耐熱鋼およびその製造方法
JP3956602B2 (ja) * 2000-10-13 2007-08-08 株式会社日立製作所 蒸気タービン用ロータシャフトの製造法
JP4262414B2 (ja) * 2000-12-26 2009-05-13 株式会社日本製鋼所 高Ｃｒフェライト系耐熱鋼

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3263732B1 (fr) * 2015-02-27 2022-04-13 National Institute for Materials Science Acier ferritique résistant à la chaleur et son procédé de fabrication

Also Published As

Publication number Publication date
JP2007092123A (ja) 2007-04-12
EP1770182A1 (fr) 2007-04-04
US20110126540A1 (en) 2011-06-02
JP4542491B2 (ja) 2010-09-15
US20070071599A1 (en) 2007-03-29

Similar Documents

Publication Publication Date Title
EP1770182B1 (fr) Acier coulé à haute résistance mécanique et résistant à la chaleur ainsi que son procédé de fabrication et ses applications
US5749228A (en) Steam-turbine power plant and steam turbine
EP1067206B1 (fr) Aube de turbine à vapeur pour une centrale à vapeur
EP1770184B1 (fr) Acier martensitique coulé thermorésistant à haute résistance et procédé de sa fabrication
KR100414474B1 (ko) 고강도내열주강,증기터빈케이싱,증기터빈발전플랜트및증기터빈
US6129514A (en) Steam turbine power-generation plant and steam turbine
US6358004B1 (en) Steam turbine power-generation plant and steam turbine
EP1466993B1 (fr) Acier résistant à la chaleur et turbine à gaz et composants réalisées en cet acier
JP2006022343A (ja) 耐熱鋼とそれを用いた蒸気タービン用ロータシャフト及び蒸気タービン並びに蒸気タービン発電プラント
EP0759499B1 (fr) Installation de turbines à vapeur et turbine à vapeur
US5428953A (en) Combined cycle gas turbine with high temperature alloy, monolithic compressor rotor
JP3362369B2 (ja) 蒸気タービン発電プラント及び蒸気タービン
JP2001098349A (ja) 高強度マルテンサイト鋼
JPH09287402A (ja) 蒸気タービン用ロータシャフト及び蒸気タービン発電プラントとその蒸気タービン
JP2000161006A (ja) 蒸気タービン翼とそれを用いた蒸気タービン及び蒸気タービン発電プラント並びに高強度マルテンサイト鋼
JP3800630B2 (ja) 蒸気タービン発電プラント及び低圧蒸気タービンの最終段動翼とその製造法
JPH10317105A (ja) 高強度鋼，蒸気タービン長翼及び蒸気タービン
US6305078B1 (en) Method of making a turbine blade
JP3632272B2 (ja) 蒸気タービン用ロータシャフトとその製造法及び蒸気タービン発電プラントとその蒸気タービン
JPH07118812A (ja) 耐熱鋳鋼タービンケーシング及びその製造法
JP3362371B2 (ja) 蒸気タービン及び蒸気タービン発電プラント

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK YU

RTI1 Title (correction)

Free format text: HIGH-STRENGTH HEAT RESISTING CAST STEEL, METHOD OF PRODUCING THE STEEL, AND APPLICATIONS OF THE STEEL

17P Request for examination filed

Effective date: 20071004

17Q First examination report despatched

Effective date: 20071107

AKX Designation fees paid

Designated state(s): DE GB

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RIN1 Information on inventor provided before grant (corrected)

Inventor name: YODA, HIDEO C/O HITACHI, LTD., INT. PROP. GROUP

Inventor name: KAWANAKA, HIROTSUGU C/O HITACHI, LTD., INT. PROP.

Inventor name: ARAI, MASAHIKOC/O HITACHI, LTD., INT. PROP. GROUP

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602006026327

Country of ref document: DE

Effective date: 20120301

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20120917

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602006026327

Country of ref document: DE

Effective date: 20120917

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602006026327

Country of ref document: DE

Representative=s name: MERH-IP MATIAS ERNY REICHL HOFFMANN, DE

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602006026327

Country of ref document: DE

Representative=s name: MERH-IP MATIAS ERNY REICHL HOFFMANN, DE

Effective date: 20140716

Ref country code: DE

Ref legal event code: R081

Ref document number: 602006026327

Country of ref document: DE

Owner name: MITSUBISHI HITACHI POWER SYSTEMS, LTD., YOKOHA, JP

Free format text: FORMER OWNER: HITACHI, LTD., TOKYO, JP

Effective date: 20140716

Ref country code: DE

Ref legal event code: R081

Ref document number: 602006026327

Country of ref document: DE

Owner name: MITSUBISHI HITACHI POWER SYSTEMS, LTD., YOKOHA, JP

Free format text: FORMER OWNER: HITACHI, LTD., TOKYO, JP

Effective date: 20120111

Ref country code: DE

Ref legal event code: R082

Ref document number: 602006026327

Country of ref document: DE

Representative=s name: MERH-IP MATIAS ERNY REICHL HOFFMANN PATENTANWA, DE

Effective date: 20140716

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20150528 AND 20150603

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20200916

Year of fee payment: 15

Ref country code: DE

Payment date: 20200916

Year of fee payment: 15

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602006026327

Country of ref document: DE

Representative=s name: MERH-IP MATIAS ERNY REICHL HOFFMANN PATENTANWA, DE

Ref country code: DE

Ref legal event code: R081

Ref document number: 602006026327

Country of ref document: DE

Owner name: MITSUBISHI POWER, LTD., JP

Free format text: FORMER OWNER: MITSUBISHI HITACHI POWER SYSTEMS, LTD., YOKOHAMA-SHI, KANAGAWA, JP

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602006026327

Country of ref document: DE

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20210927

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20210927

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20220401