Steam Turbine Materials for Ultrasupercritical Coal Power Plants

Viswanathan, R.; Hawk, J.A.; Schwant, R.; Saha, Deepak; Totemeier, T. C.; Goodstine, S.; McNally, M. J.; Allen, D.; Purgert, Robert

doi:10.2172/1081317

Cited by 17 publications

(14 citation statements)

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“…This kind of 18%Cr-9%Ni steel contains with about 0.7%Nb and it keeps higher allowable stress and creep rupture strength than TP304, TP321H and TP316H (Viswanathan, 2009). The chemical composition of TP347H steel for our research is as follows(in mass%): 0.07C, 0.35Si, 1.35Mn, 0.016P, 0.003S, 11.22Ni, 18.08Cr, 0.68Nb, bal.…”

Section: Tp347h Heat-resistant Steelmentioning

confidence: 99%

Advanced Austenitic Heat-Resistant Steels for Ultra-Super-Critical (USC) Fossil Power Plants

Chi¹,

Yu²,

Xie³

2011

Alloy Steel - Properties and Use

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Section: Tp347h Heat-resistant Steelmentioning

confidence: 99%

Advanced Austenitic Heat-Resistant Steels for Ultra-Super-Critical (USC) Fossil Power Plants

Chi¹,

Yu²,

Xie³

2011

Alloy Steel - Properties and Use

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“…This high-temperature performance is due to the presence of L1 2 ordered γ ′ precipitates from face-centered cubic (fcc) γ matrix with certain constrained lattice mis t. Ni-based superalloys are considered promising materials for increase in operating temperature and/or time in A-USC applications, many of these materials have recently been screened using long-term creep tests 2,3) . However, this screening has revealed that not all alloys have suf cient long-and short-term strength.…”

Section: Introductionmentioning

confidence: 99%

Morphology Evolution of γ′ Precipitates during Isothermal Exposure in Wrought Ni-Based Superalloy Inconel X-750

2017

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The morphological evolution of γ ′ precipitates and lattice mis t with isothermal aging were closely investigated in wrought Ni-based superalloy Inconel X-750. The γ ′ morphology dramatically changes in terms of shape, distribution, coalescence and coherency at the γ/γ ′ interface. These processes and their dependence on temperature are summarized as a γ ′ morphology map together with a time-temperature-precipitation (TTP) diagram through quantifying relevant morphological parameters. The lattice mis t was measured by X-ray diffraction and is positive; it decreases from 0.6% at room temperature to 0.1% at the aging temperature. These results suggest that the morphological changes of the γ ′ precipitates are attributable to very low lattice mis t, the interaction of the elastic eld, the volume fraction of the precipitates and incoherence in γ/γ ′ interface.

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“…1 Therefore, the goal of advanced ultrasupercritical steam conditions up to 37?5 MPa and 700uC with an efficiency of circa 50% has been proposed. 2,3 However, the ability to increase operating temperature is limited by material properties. 4 One application with such a limitation is superheater/reheater tubes and header pipes utilised in advanced ultrasupercritical steam boilers.…”

Section: Introductionmentioning

confidence: 99%

Structural stability and mechanical properties of phosphorus modified Ni–Fe based superalloy GH984

Wang

Zhao

Guo

et al. 2014

Materials Research Innovations

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GH984 is a Ni-Fe based superalloy that has been used as superheater tube material in high pressure boilers for more than 10 years, and is now being considered for use as superheater, reheater and header material for boilers in 700uC advanced ultrasupercritical (A-USC) coal fired power plants. In order to meet the requirements of 700uC A-USC boilers, the alloy composition must be optimised to enhance thermal stability and improve mechanical properties. In this paper, the influence of phosphorus (P) on the structural stability and mechanical properties of the GH984 alloy was investigated. The results show that P has no influence on the major precipitates, which are spherical c9, blocky MC and discrete M 23 C 6 at the grain boundary after standard heat treatment, except decreases in the size of M 23 C 6 . After the thermal exposure at 700uC for 1000 h, at the grain boundary, the morphology of M 23 C 6 changes from a blocky and irregular shape to a blocky and nodular shape, and the size decreases with the increase in P content. Additionally, the growth rate of M 23 C 6 increases with increasing the thermal exposure temperature from 700 to 800uC. The P content has no obvious influence on the tensile strength and ductility. However, at 700uC/350 MPa and 750uC/300 MPa, the rupture life obviously increases with increasing the P content due to the improvement of grain boundary strength when the content of P is lower than 0?034 wt-%. It can be concluded that the addition of P can increase the rupture life and improve the structural stability of GH984.

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Steam Turbine Materials for Ultrasupercritical Coal Power Plants

Cited by 17 publications

References 0 publications

Advanced Austenitic Heat-Resistant Steels for Ultra-Super-Critical (USC) Fossil Power Plants

Advanced Austenitic Heat-Resistant Steels for Ultra-Super-Critical (USC) Fossil Power Plants

Morphology Evolution of γ′ Precipitates during Isothermal Exposure in Wrought Ni-Based Superalloy Inconel X-750

Structural stability and mechanical properties of phosphorus modified Ni–Fe based superalloy GH984

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