High-Temperature Corrosion of Aluminized and Chromized Fe-25.8Cr-19.5Ni Alloys in N_2/H_2S/H_2O-mixed

摘要

Alloys of Fe-25.8%Cr-19.5%Ni (SUS310 stainless steel) were either chromized or aluminized via pack cementation, andcorroded at 800 °C for 100 h in 1 atm of (0.9448 atm of N_2+0.031 atm of H_2O+0.0242 atm of H_2S)-mixed gases. The chromized layer consisted primarily of Cr_(1.36)Fe_(0.52) and some Cr_(23)C_6. Its corrosion resulted in the formation of Cr_2S_3 and some FeS and Fe_5Ni_4S_8. The aluminized coating consisted primarily of FeAI. Itscorrosion resulted in the formation of α-Al_2O_3, Al_2S_3, and Cr_2S_3. Aluminizing was more effective than chromizing in increasing the corrosion resistance of the substrate, due mainly to the formation of α-Al_2O_3.