Abstract
HR-120TM alloy is a Ni-Fe-Cr alloy designed to have high strength at elevated temperature and resistance to attack in carburizing and sulfidizing environments. Applications for this alloy include components to be assembled in combustion turbines for power generation. Some of these components can be manufactured by ring-rolling procedures followed by heat treating operations. Typically, HR-120TM alloy is heat-treated in a temperature range of 1175 to 1230°C in order to promote microstructure homogenization and dissolution of heavy precipitates. An inconvenience of such heat-treating temperature range is related to excessive grain-size coarsening of wrought parts. This work presents the results of a series of heat-treatment procedures performed on seamless rings produced by ring-rolling considering industrial conditions. Lower heat-treatment temperatures are considered for evaluation of mechanical and microstructural properties. It is reported that an excellent combination of mechanical properties and microstructural characteristics is obtained when alloy is exposed to 1050°C for soaking periods above 30 minutes.
