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Mechanical Performance of Various INCONEL® 740/740H Alloy Compositions for Use
in A-USC Castings
The use of Ni-based superalloys as structural components of advanced
ultra-supercritical steam and CO2 turbines is becoming necessary due to the
increasing performance requirements of future power plant designs. Although
numerous Ni-based superalloys can respond to the demanding mechanical
performance, very few present a combination of high-strength and creep
resistance while maintaining good ductility and weldability. Furthermore, the
improved performance is often associated with wrought alloys while the
fabrication of large castings is the primary target for those applications. With
the comparatively lower mechanical properties of cast alloys, new designs based
on compositional changes are necessary to allow for the use of Ni-based
superalloys in A-USC castings. This lack of performance is primarily associated
with the large and inhomogeneous grain size as well as elemental segregation and
other casting anomalies. This investigation presents various alloys with
compositions within the range of INCONEL® 740/740H designed to overcome the
issues associated with the use of Ni-based superalloys in A-USC castings.
Modifications to the chemistry were based on thermodynamic simulations and
experimental results. Particular attention was given to reactive element
additions, element partitioning, ¦Ãʹ precipitate phase promoting elements and
grain boundary carbides. The effects of the various compositional changes on the
tensile and creep properties of INCONEL® 740/740H will be discussed.
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Hastelloy G -30 / UNS N06035 HASTELLOY C-2000 (FOR SPRINGS) Monel 404 (UNS N 04404)
Nimonic90 Nickel 2.4683 (Alloy 188) Haynes˘ 214 Haynes 556 / UNS R30556 / 1.4883 Haynes 230® - 2.4733 - alloy 230 Monel 401 Metal piping
Hastelloy N / UNS N10003 Hastelloy B Alloy 926 / 6Mo alloy a 286 uns ss28286 1.498 alloy 28 UNS N08028, alloy 20 UNS N08020
INCOLOY® alloy 330 Incoloy 901® - 2.4975 - Alloy 901 Incoloy 028 1.4563 / Sanicro28 Inconel 693® - Alloy 693 Inconel 706 INCONEL® 740/740H Alloy
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Hastelloy B-3 / UNS 10675 / 2.4600 Hastelloy C-4 / N06455 / 2.4610 Hastelloy X / N06002 / 2.4665 Monel 400 / UNS N04400 / 2.4360