Effects of temperature on oxidation behaviours of 35CrMo in high temperature flue gas environment

The pipelines made by alloy 35CrMo are widely used in the process of flue gas injection. Therefore, corrosion behaviours of alloy 35CrMo have been investigated at varied temperatures, namely 120 °C, 150 °C, 200 °C and 250 °C, with same experimental pressure of 9 MPa and flus gas environment. Scanning electron microscopy was employed to examine the morphologies and microstructures of the oxide films. The results indicated that moderate temperature stands an essential role in the reaction mechanism and aggressive effects. In addition to increase in the diffusion rate of both alloy ions and corrosive gas, temperature can also reform the morphology of oxides by resulting in larger oxide particles and thicker oxide films, plus the transmission from needle-like oxides to spherical oxides.