Abstract

Study of some characteristics describing the oxidation of a {m, m�?�?�?�?�?�?�?�?}-based {30Cr, 1C, 15Ta} containing alloy during heating up to high temperature and the oxide scales behavior during post-{isothermal stage} cooling. part 3: {m, m�?�?�?�?�?�?�?�?}={Fe, Ni}

Author(s): Ga�?�?�?�?�?�?�?«l Pierson, Kevin Duretz, Thierry Schweitzer, Elodie Conrath, Patrice Berthod

An alloy based on iron and nickel in equal parts, rich in chromium and containing a dense TaC network in itsmicrostructure was tested in oxidation at high temperature in dry synthetic air. The thermogravimetry tests were performed at 1000, 1100 and 1200°C during 40 hours. The mass gain files were plotted versus temperature and exploited to specify the oxidation start during heating and spallation start during cooling temperatures as well as the successive parts of mass gain achieved during heating and during the isothermal stage. The mass gain kinetic at 1000°C is quite parabolic and the rate rather low. The mass gain curves obtained at 1100 and 1200°C are in contrast affected by the occurrence ofmas gain jumps. The oxidation kinetic during the heating and the isothermal stage are closer to the one of the NiCo-based alloy previously studied than to the CoFe-based one. Concerning the behaviour of the oxide scale during the post-isothermal stage cooling the behaviour of this FeNi-based alloys is similar to the two others alloysÂ’ one, as is to say severe spallation also occurred here. Metallographic characterizationwill be soon undertaken for the three alloys.