High temperature corrosion behavior of siliconized 310 stainless steel

Surface alloying of Si into AISI 310 austenitic stainless steel (SS) to inc rease its high temperature corrosion resistance was attempted by employing pack cementation process. High temperature corrosion resistances of AISI 31 0 SS with or without siliconization treatment were evaluated in air and in CO/CO2 gas mixtures at 700, 750 and 800 degrees C. The experimental results showed that the weight losses for both 310 SS and siliconized 310 SS in CO /CO2=10/1 reducing gas environment were less than those in air atmosphere a t the temperatures tested. Furthermore, siliconization treatment provided b etter high temperature corrosion resistance for 310 SS both in air and in r educing gas environment. Compositional and structural analyses showed that the oxides formed on 310 stainless steel were composed of an outer spinel o f Cr/Mn/Fe oxide and an inner layer of chromium oxide in air and reducing g as environments. For siliconized stainless steel, SiO2 was found in the oxi de layer after high temperature exposure in the gas environments tested. (C )2000 Elsevier Science S.A. All rights reserved.