Comparison of the high temperature chloride induced corrosion between a Duplex steel and a Ni based alloy

摘要

The Duplex steel 1.4462 and the Ni based alloy Centralloy ET45 micro were tested in an HCl containing atmosphere with a low oxygen pressure at 680 °C for 72 h. The composition of the gas atmosphere was 3.8 vol.% HCl, 1.9 vol.% CO_2, 0.3 vol.% CO, 2.8 vol.% H_2, 0.02 vol.% H_2S, bal. N_2. The calculated oxygen partial pressure is 10~(-24) bar and the chlorine partial pressure is 10~(-13) bar. Thermodynamic considerations show that the phases Cr_2O_3, FeCl_2 and metallic Ni are stable in this gas atmosphere at 680 °C.