Superalloys in modern power generation applications

Abstract

It is widely recognised that for the foreseeable future coal will remain an important energy source for generation of electric power in many areas of the world. However, it will be essential to develop generation technologies that include the capture and storage of emissions such as CO2 to combat the harmful effects of climate change. The key to the successful implementation of advanced generation technologies, the ultimate aim of which is the zero emission power plant, depends heavily on the availability of suitable materials. In this paper, the requirements for materials with improved high temperature performance will be considered in the context of three types of power generation system being developed to operate with greatly reduced emissions and with high levels of efficiency. The limitations of existing materials will be outlined and the need for materials with higher temperature capabilities and good fabricability will be discussed.

Characterisation of microstructure and creep properties of alloy 617 for high-temperature applications

“…These have been used to date in relatively short term applications such as turbine engines in the aerospace industry. Forecasted requirements for USC applications have set the targets at minimum creep strength of 100 MPa at 100000 h of service [1][2][3][4][5][6][7]. Since the microstructure of most of the candidate nickel base alloys has not been investigated after such long exposure periods of time, modelling activity has proven to be helpful in predicting the material microstructural response under simulated service conditions [8].…”

Electrodes With Various Amount of Nickel for Truck Frame Repairs

“…The amount of 2% Ni could be treated as optimal. The influence of nickel content in weld metal deposit on impact toughness was well analysed by many researchers [1][2][3][11][12][13][14][15]. Literature data on the fatigue properties of frames after welding with various amounts of nickel were not given so explicitly [3,12].…”

“…The chemical composition of welded metal deposit could be regarded as a very important factor influencing properties of weld metal deposit (WMD). The influence of nickel content in weld metal deposit on plastic properties was well analysed by many researchers in the last 15 years [1][2][3][11][12][13][14][15]. The influence of nickel on impact toughness of welds is presented below (fig.…”

High-temperature microstructural evolution and quantification for alloys IN740 and IN740H: comparative study

“…Such high temperature applications led the research focus on high creep resistance. Forecasted requirements in the power generation sector have set the targets to minimum creep strength of 100 MPa at 100000 h of service [1][2][3][4][5][6][7]. Two possible candidate materials for USC boiler applications are the high chromium Ni-base precipitation-hardenable superalloy IN740 and its modification, IN740H, both developed by Special Metals [5,7,[8][9][10][11][12][13][14][15].…”