Utilities worldwide are facing increased demand for additional electricity, reduced plant emissions and greater efficiency. Part of the solution is achieved by increasing boiler temperature, pressure and coal ash corrosion resistance of the materials of boiler construction. In this paper, a new nickel-base tube alloy, INCONEL alloy 740, meeting this challenge is characterized with emphasis on mechanical properties, coal ash and steam corrosion resistance as well as weldability. Microstructural stability as a function of temperature and time is addressed as well as some of the early methodology employed to arrive at the current chemical composition. Brief mention is made of certain current and future alloy characterization efforts and potential environmental benefits to be expected should the boiler technology utilizing INCONEL alloy 740 be adopted.

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