Effect of Si Content on Oxidation Behavior of Quaternary Fe-20Ni-20Cr-ySi Alloys in Oxygen at 900℃
The oxidation behavior of Fe-20Ni-20Cr-ySi(y=0,1,3,5,mass fraction,％)alloys were studied in 1 atm O2 at 900℃ for 24 h.After oxidation,Fe-20Ni-20Cr alloy without Si addition formed a complex oxide scale on the surface with poor protectiveness.When the Si content increased from 1％to 3％,a transition from internal to external oxidation of Si occurred.Therefore,additions of Si can signifi-cantly improve the oxidation resistance of the austenitic Fe-20Ni-20Cr alloy.Both Fe-20Ni-20Cr-3Si and Fe-20Ni-20Cr-5Si formed an amorphous SiO2 layer on the Cr2O3/alloy interface,and this continuous amorphous SiO2 layer provided an effective barrier to prevent the outward diffusion of Fe,Ni and Cr,as well as the inward migration of oxygen.A comparison of the oxidation behavior of alloys with different Si contents indicated that Fe-20Ni-20Cr-3Si has the most excellent oxidation resistance properties.
Fe-Ni-Cr-Si alloysiliconhigh temperature oxidationoxidation kinetics
NETL
NSTL
万方数据
