Solution and Aging of MAR-M246 Nickel-Based Superalloy

Abstract

Solution and aging heat-treatments play a key role for the application of the superalloys. The aim of this work is to evaluate the microstructure of the MAR-M246 nickel-based superalloy solutioned at 1200 and 1250°C for 330 min and aged at 780, 880 and 980°C for 5, 20 and 80 h. The c¢ solvus, solidus and liquidus temperatures were calculated with the aid of the JMatPro software (Ni database). The as-cast and heattreated samples were characterized by SEM/EDS and SEM-FEG. The c¢ size precipitated in the aged samples was measured and compared with JMatPro simulations. The results have shown that the sample solutioned at 1250°C for 330 min showed a very homogeneous c matrix with carbides and cubic c¢ precipitates uniformly distributed. The mean c¢ size of aged samples at 780 and 880°C for 5, 20 and 80 h did not present significant differences when compared to the solutioned sample. However, a significant increasing in the c¢ particles was observed at 980°C, evidenced by the large mean size of these particles after 80 h of aging heat-treatment.

The Evolution of Cast Microstructures on the HAZ Liquation Cracking of Mar-M004 Weld

“…In contrast, the B could be detected in other zones of the solidification products. The results also indicated that M 3 …”

“…Commercial Ni-based superalloys are widely applied for making critical components in gas turbine engines, which require excellent mechanical and anti-corrosion properties at elevated temperature [1][2][3][4]. Mar-M004, a cast Ni-based superalloy, is strengthened primarily by Ni 3 (Al, Ti) γ precipitates, which are responsible for the stable mechanical properties during long-term applications at elevated temperature [5].…”

Isothermal short‐term oxidation behavior of MAR‐M246 nickel‐based superalloy at 800°C and 1000°C

“…Figure 3a illustrates the microstructure of MAR‐M246 superalloy in the as‐cast state, showing a dendritic microstructure containing carbides of different sizes and morphologies in the interdendritic region. EDS analyses of the carbides in the as‐cast sample were presented in a previous article, [ 20 ] which described the presence of Ti, Cr, Mo, Ta, and W as the main elements in this phase. Figure 3b shows γ' precipitates inside the dendrites.…”

Avaliação do comportamento mecânico em fluência e de oxidação da superliga MAR-M246 convencional e modificada pela substituição do Ta pelo Nb

“…De acordo com os resultados apresentados neste estudo, ambas as ligas apresentaram características microestruturais iniciais semelhantes em termos de fases existentes, o que deve estar relacionado à menor variação da composição química entre elas e às similaridades químicas entre Nb e Ta. Tais semelhanças foram previstas por simulações termodinâmicas (BALDAN et al, 2017) e comprovadas por esta pesquisa (Figuras 13 a 22, Tabelas 6 a 8). Além disso, os resultados deste estudo concorda com as evidências destacadas por outros autores de que a substituição total de Ta por Nb não influencia significativamente o conteúdo quantitativo dos elementos nas fases em que participam (AZEVEDO E SILVA et al, 2013;BALDAN et al, 2013aBALDAN et al, , 2013b.…”

“…Entretanto, as amostras revestidas exibiram uma maior perda de massa por destacamento (spalling) dos revestimentos de barreira térmica, a qual a barreira de duas camadas baseada em Ni-20Cr/ZrO2-5CaO sofreu um severo destacamento. Kadioglu e Sehitoglu (1996) Fonte: Adaptado de (BALDAN et al, 2017).…”