Comparison of the Cyclic-Oxidation Behavior between AISI 304 and Low-Nickel Austenitic Stainless Steels

Abstract

The resistance to thermal cycling of two low nickel austenitic stainless steels 16-7 MnSi (16.4 Cr 7.5 Mn 1.6 Ni 0.8 Si 2.8 Cu 0.2 N bal. Fe), 17-10Mn (17 Cr 10.5 Mn 2.7 Ni 0.2 Si 1.9 Cu 0.16 N bal. Fe) has been investigated in air at 1023-1123 K and compared to a standard AISI 304 grade. At 1123 K generalised spallation occurred after 150 cycles and led to poor protective Fe-rich scale formation for these three grades. At 1023 K, 16-7 MnSi exhibited the best cyclic oxidation and oxide adhesion behaviour while the 17-10 Mn alloy showed the poorest with an important scale spallation. The higher Si content in 16-7 MnSi was beneficial at 1023 K in promoting a thin continuous protective SiO 2 scale under the chromia layer. The absence of this SiO 2 layer on 17-10 Mn resulted in thicker and less protective scales. The thermal cycles favoured partial spallation on 17-10 Mn and AISI 304, thus allowing the easier formation of a less protective scale formed by M 3 O 4 (M=Fe, Cr, Mn) and outer Fe-rich oxides and internal attacks. 16-7 MnSi offers good refractory properties and can be considered as an interesting substitute.