COMPARISON OF BEHAVIOUR TO OXIDATION AT HIGH TEMPERATURE OF TWO SUPERALLOYS: INCONEL 713C AND IC-50

摘要

This paper focuses on the behaviour at air oxidation of the high alloys as IC-50 and 713C at high temperature. The specimens were oxidised in a thermogravimetric microbalance for 24 h at 900，1000, 1100, 1200 and 1300°C. The oxidation behaviour of IC-50 showed bimodal parabolic growth kinetics, that is, a parabolic growth rate for the first three hours of the test (initial stage of oxide film growth) with parabolic growth constant K_1 and another parabolic growth rate for longer test times with a parabolic growth constant K_2, where K_1 > K_2. However, alloy Inconel 713C showed parabolic growth kinetics, upon disregarding the initial stages of oxide formation. Therefore, in terms of high temperature oxidation, the alloy Inconel 713C showed good behaviour at all test temperatures, that is, low parabolic growth constants (Kp), compared to other alloys of the Ni-Cr-Al system. This behaviour of alloy Inconel 713C indicates formation of a continuous and non-porous film of Al_2O_3 which is highly resistant to high temperature oxidation.