The ever-increasing demand for energy drives the need for inventing and designing improved materials. Coal based power plants continue to meet most of the energy requirements and the trend is expected to continue for the coming decade or so. Presently in India, most of the thermal power plants in existence are of sub-critical type, whose operating conditions are of 550°C and 22 MPa. The net efficiency of such power plants is less than 35%. Advanced Ultra Super Critical (AUSC) power plants aim to achieve steam conditions of 700-725°C and 25-35 MPa, thereby increasing the overall efficiency to 45-52%. This calls for materials that can sustain prolonged exposures at elevated temperatures and harsh environments. Materials meant for such applications have to endure the simultaneous imposition of stress, steamside and fireside corrosion and thermal fatigue. For Indian AUSC power plants, stainless steel 304HCu and alloy 617 are being considered as candidate materials for reheater and superheater applications, respectively. In recent years, microstructural modification through grain boundary engineering (GBE) has been shown to improve resistance to creep deformation, hot corrosion, oxidation and intergranular corrosion. I will present a critical review of literature on the role of microstructure on the creep deformation and hot corrosion. Based on the review, the gaps in understanding are identified and research plan is presented. The experimental research plan involves evaluating the creep deformation behavior and interaction of hot corrosion and creep for the above-mentioned materials. In the first part of the work, the GBE microstructure will be achieved in SS 304 HCu and alloy 617 through thermomechanical processing. Subsequently, the role of GBE microstructure on creep rupture response and hot corrosion and interaction of creep and hot corrosion will be evaluated and compared with those in the as-received condition. Preliminary creep rupture test results on SS 304HCu and alloy 617 were conducted and the results of the same will be discussed.