High Temperature Oxidation Behavior of F55 Super Duplex Stainless Steel at 800-1000℃ in 1.013×105 Pa O2
The oxidation behavior of F55 duplex stainless steel in 1.013 x 105 Pa pure oxygen at 800,900,1000℃ has been studied by means of thermal gravimetric analyzer,optical microscope,scan-ning electron microscope(SEM)and X-ray diffraction(XRD).The results show that the oxide scales are mainly composed of Cr2O3 and Cr-Mn oxides at the designed temperatures.The oxidation kinetics curves follow parabolic law,and the oxidation mass gain increases with the increase of temperature.During the oxidation process,the α phase on the surface of the alloy changes into y phase due to the outward diffu-sion of Cr,while the α phase in the matrix undergoes eutectoid reaction to form σ+γ and other phases.Cr in the σ phase generated by the eutectoid reaction preferentially diffuses to the surface of the alloy to participate in the oxidation reaction.
F55 duplex stainless steelhigh temperature oxidationphase changeeutectoid reaction