Effect Of Titanium、Niobium、Cobalt And Zirconium On Microstructure And Mechanical Property Of High Temperature Alloy25cr37ni0.6Nb

High temperature alloys have greatly broadened their applications in allaspects since their advent in China over50years. High temperature alloysare leading important roles, especially in aerospace engines, industry gasturbines and naval powers. HR120(UNS08120) is a solid solutionstrengthening of high-temperature alloy, with great high temperaturestrength and excellent resistance to carbonization and sulfidation. As thisalloy widely used, this paper designed four alloys on the base of HR120alloy to meet the need to develop new products. Besides, the simulationsoftware JMatPro was employed to analyze the effect of differentalloying elements on the alloy precipitates, and optical microscopy (OM),Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy(EDS), room temperature tensile test, high temperature tensile and creepand other experimental methods were utilized to research the effect ofadding alloy elements Ti, Nb, Co and Zr, and increasing alloy element Nb,and solution temperature and time on the microstructure and mechanicalproperties of test alloys. The main conclusions are as follows:(1) According to the calculation results of the phase diagram: adding Cointo alloy, phase was increased and stabled, the formation of BCC（α-Cr）was inhibited. Adding Ti into alloy, σ,、’phase were precipitated,the precipitation of Cr23C6was delayed. Increasing the Nb content in thealloy, the number of σ phase was increased and precipitation of Cr23C6was inhibited.(2) With the increasing of solution temperature, the alloy grain grewbigger，room temperature strength was decreased, creep property wasreduced. When temperature at1180℃, the number of alloy precipitates was the maximum.(3) When solution time ranged from1h to1.5h, the number ofprecipitates was reduced, room temperature strength was decreased, creepperformance did not change significantly.(4) Adding Ti to blank sample(alloy E), room temperature and hightemperature performance were reduced. Improving the content of Nb ofalloy E, room temperature strength was slightly elevated. Adding Co toalloy E, creep performance was improved. Adding Zr to alloy E, alloyproperty did not change significantly.