Microstructural investigation of GTD 111DS materials in the heat treatment conditions

Lifetime extension prediction of the rejuvenated first stage gas turbine blades

“…In order to extend the lifespan of turbine run buckets cast from DS GTD-111 superalloys, the RHT protocol in vacuum furnace (1204°C (2 h) + 1121°C (2 h) + 843°C (4 h)) previously discussed by Chang-Sung Seok et al [15], and Warren Miglietti et al [16], was implemented. These blades are heat treated first at 1204°C to homogenise the substrates microstructures by dissolving the coarsened γ′ precipitates and the nucleated detrimental topologically close packed (TCP)-phases as well.…”

Study of microstructure degradation and rejuvenation evolution for F-class gas turbine blade

“…The sample blades are made from GTD111 DS superalloy as substrates, thermal barrier coatings on the external surface and aluminide coating on the internal cooling channel surface. The nominal chemical composition (by wt-%) of GTD111 DS is given as follows (wt-%): 13.6% Cr, 9.14% Co, 4.9% Ti, 2.97% Al, 3.44% W, 1.6% Mo, 2.87% Ta, 0.09% C, 0.01% B and balance nickel [15]. The plate specimens for metallographic observation are cut from shank, aerofoil leading, trailing edges and platform, respectively.…”

“…Previously, many studies toward microstructure and properties recovery of thermally exposed superalloys by HIPcombined rejuvenation heat treatment have been conducted [7,8]. In recent years, HIP-combined rejuvenation heat treatment have been widely applied in lifetime extension of turbine blades, referring to most of equiaxed cast superalloys such as Udimet 500, Rene 80, Nimonic 263, Mar M247, IN738, IN939, GTD 111, Hastelloy X and FSX 414 [9][10][11][12][13][14], and a few direction-ally solidified superalloys such as GTD111 (DS) and DD6(SX) [15,16]. It is well known that HIP can effectively eliminate creep voids and the implementation of rejuvenation heat treatment can restore microstructure of even overaged blades to a nearly 'as-new' condition [5,17].…”