This paper reviews the differences between two nickel based alloys, Alloy 740 and Alloy 740H. Microstructural evolution models are used to forecast the changes in volume fraction and interparticle spacing of both grain boundary and intra-granular precipitates in the alloys. These data are then employed in continuum damage mechanics models to forecast creep curves, and in fracture mechanics models to forecast Charpy impact energies/energy. The results reveal the key microstructural features that control secondary and tertiary creep rate as well as the time dependence of Charpy impact energy after high temperature exposure.
ViswanathanR. and BakkerW.: ‘Materials for ultrasupercritical coal power plants-boiler materials, part 1’, J. Mater. Eng. Perform., 2001, 10, 81–95. doi: 10.1361/105994901770345394
2.
GibbonsT. B.: ‘Superalloys in modern power generation applications', J. Mater. Sci. Technol., 2009, 25, 129–135. doi: 10.1179/174328408X355433
3.
SharmaA., BuhreB. J. J. P., RichardsonS., SperoC. and WallT.: ‘Fired supercritical boilers operational issues and coal quality impacts', Technical Note 20. CCSD. Cooperative Research Centre for Coal in Sustainable Development, Report, 2002.
4.
ViswanathanR.: ‘U.S. program on materials technology for ultra-supercritical coal power plants', J. Mater. Eng. Perform., 2005, 14, 281–292. doi: 10.1361/10599490524039
5.
ReedR. C.: ‘The superalloy fundamentals and applications', 2006, Cambridge, Cambridge University Press.
6.
ShingledeckerJ. P., SwindemanR. W., WuQ. and VasudevanV.K.: ‘Creep strength of high temperature alloys for ultra-supercritical steam boilers', 4th EPRI Conference on Advances in Materials Technology for Fossil Power Plants, 2007.
7.
DonachieM. J. and DonachieS. J.: ‘Superalloys a technical guide’, 2002, Materials Park, OH, ASM International.
8.
SandströmR., FarooqM. and ZurekJ.: ‘Basic creep models for 25Cr20NiNbN austenitic stainless steels', Mater. Res. Innov., 2013, 17, 355–359. doi: 10.1179/1433075X13Y.0000000120
9.
VujicS., BealC., SommitschC., FarooqM., SandströmR. and ZurekJ.: ‘Modelling and optimizing precipitation in creep resistant austenitic steel 25Cr–20Ni–Nb–N’, 7th Int. Conf. on Advances in Materials and Technology for Fossil Power Plants, 2013, 1163–1172.
10.
YinY. F. and FaulknerR. G.: ‘Continuum damage mechanics modelling based on simulation of microstructural evolution kinetics', J. Mater. Sci. Technol., 2006, 22, (8), 929–936. doi: 10.1179/174328406X102426
11.
DysonB.: ‘Use of CDM in marerials modelling and component creep life prediction’, J. Pressure Vessel Technol., 2000, 122, 281–296. doi: 10.1115/1.556185
12.
Di MartinoS. F., FaulknerR. G. and HoggS. C.: ‘Characterisation of microstructure and creep predictions of alloy IN740 for ultrasupercritical power plants', J. Mater. Sci. Technol., 2014, 31, (1), 48–58. doi: 10.1179/1743284714Y.0000000567
13.
RatkeL. and WoorheesP.W.: ‘Growth and coarsening, ostwald ripening in materials processing’, 2002, Berlin, Springer.
14.
RajR.: ‘Separation of cavitation-strain and creep-strain during deformation’, J. Am. Ceram. Soc., 1982, 65, C-46. doi: 10.1111/j.1151-2916.1982.tb10397.x
15.
CocksA. C. F. and AshbyM. F.: ‘On creep fracture by void growth’, Prog. Mater Sci., 1982, 27, 189–244. doi: 10.1016/0079-6425(82)90001-9
