Abstract Scope |
This paper describes the advanced alloy design program (AADP) and improvement of a 6th generation single crystal superalloy, TMS-238, using this AADP. Creep rupture life prediction equations for five different creep conditions, 800 °C /735 MPa, 900 °C /392 MPa, 1000 °C /245 MPa, 1100 °C /137 MPa, and 1150 °C /137 MPa, were obtained with excellent determination coefficients from 0.95 to 0.98. Using the AADP, we successfully developed three alloys, TMS-238mod-A, TMS-238mod-B, and TMS-23mod-C, which have 10 °C to 22 °C higher temperature capabilities than those of the TMS-238 alloy. The AADP successfully predicted that the creep life was maximized when the volume fraction of g' phase was approximately 65% at low-temperature and high-stress conditions, such as 900 °C/392 MPa, compared to that of approximately 60% under high-temperature and low-stress conditions, such as 1100 °C/137 MPa. This prediction enables us to precisely optimize the creep property. Moreover, the prediction equation of the weight change after 1100°C/1h oxidation was also updated. The determination coefficient of this equation was R2=0.90. |