Microstructural aspects of the failure analysis of nickel base superalloys components

Failure Investigation of a Furnace Tube Support

“…The HRA drives its resistance because of the combinational effects of Fe-Ni-Cr ''HP'' or Fe-Cr-Ni ''HK.' ' The majority of the reported deterioration in hightemperature operating components are creep damage [1][2][3][4][5], microstructural degradation [6][7][8], high-temperature fatigue [9][10][11], creep fatigue [12][13][14], sigma-phase embrittlement [15][16][17][18][19], carburization [20][21][22], hydrogen damage, graphitization, thermal shock, erosion, liquid metal embrittlement, and high-temperature corrosion of various types. Generally, virtually all failures are the result of microstructural changes at high temperature.…”

Metallurgical failure analysis for a blade failed in a gas-turbine engine of a power plant

“…The application of both optical microscopy, scanning electron microscopy (SEM), and electron probe micro-analysis (EPMA) has been quite useful in characterizing microstructures of failed turbine blades during recent years [11][12][13]. Most superalloys used in turbine blades derive their strength from gamma prime precipitates formed within the individual grains during the manufacturing process [1].…”

Microstructure and Mechanical Properties of an Austenitic Heat-Resistant Steel after Service at 570 °C and 25.4 MPa for 18 Years

“…However, the steam tubes in power plants made of such stainless steels usually have to face extreme conditions such as high temperature, stress and corrosion. During exposure under these special conditions, steels are doomed to undergo microstructural evolution, leading to mechanical properties degeneration (Ref [8][9][10]. Such microstructural evolution during high-temperature and long-term service in austenite heatresistant steels mainly involves the following aspects: (1) growth of austenite grain size; (2) ripening of precipitates such as carbides and nitrides; and (3) formation and growth of rphase (Ref [8][9][10][11][12][13][14][15].…”