An Assessment of Hot Isostatic Pressing and Reheat Treatment for the Regeneration of Creep Properties of Superalloys

Dennison, J.P.; Elliott, I.C.; Wilshire, B.

doi:10.7449/1980/superalloys_1980_671_677

Cited by 1 publication

(1 citation statement)

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“…Studies conducted since have led their authors to draw varied conclusions regarding the effectiveness of rejuvenation heat treatments and HIPing. Dennison et al studied the effects of HIP and heat treatment on creep life of Nimonic 105 and IN 100 by studying interrupted creep bars and concluded that rejuvenation was ineffective because damage in the form of oxidized surface cracking was not repaired [6]. A similar study on IN738 by McLean and Tipler showed that HIP and heat treatment were effective in extending creep life providing the surface damaged regions on the test bars were removed, but that the benefit was comparable to that achieved by heat treatment alone [7].…”

Section: Introductionmentioning

confidence: 99%

Practical Experience With the Development of Superalloy Rejuvenation

Liburdi¹,

Lowden²,

Nagy³

et al. 2009

Volume 4: Cycle Innovations; Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Marine

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Material degradation is one of the primary causes of gas-turbine hot section component retirement. This is characterized by microstructural aging and subsequent loss of creep strength. Under the same temperature conditions, the longer components remain in service, the more microstructural degradation occurs. This can be evaluated both through microscopy and stress-rupture tests, quantifying the material strength under high temperature, constant load creep conditions. In an effort to extend component life and reduce replacement part costs, material rejuvenation processes have been developed and implemented over the past few decades. In total over 35 commercial superalloy rejuvenation processes were studied and it was found that many alloys can be successfully rejuvenated but others pose a greater challenge. Issues of grain growth in forged turbine components and recrystallization in single crystal components impose limits on rejuvenation processes and are areas of ongoing development. The feasibility, successes and limitations of material rejuvenation are reviewed in this paper with a particular focus on the following superalloys: GTD111, IN738, and Nimonic 115. Examples of microstructure and stress-rupture life of turbine components in both the service-exposed and rejuvenated condition are presented. Component microstructure is shown to be restored, and the stress-rupture life following rejuvenation is returned to a condition fit for continued service.

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Section: Introductionmentioning

confidence: 99%