In order to study the corrosion behaviors of candidate materials for superheater of supercritical boilers in high-temperature flue gas environment

three austenitic heat-resistant steels including S31042

S31035 and C-HRA-5 were exposed to laboratorial simulated coal-fired flue gas for hot corrosion tests. The tests were carried out at 650

675

700 and 725 °C. On the sample surface

there were three conditions including no coating

coating with real coal ash

and coating with corrosive simulated coal ash. The test duration was 500 h. The corrosion kinetic curves of the three materials were obtained through experimental research

and corrosion behaviors of the material were analyzed by XRD

SEM and EDS. Moreover

corrosion resistance of the three materials was compared. The results indicated that

the three materials had excellent resistance to oxidation and corrosion under the conditions of no coating and coating with real coal ash. Under the condition of coating with corrosive simulated coal ash

the material corrosion intensifies and the corrosion products are layered. The temperature effect was different under different coating conditions. S31042 had the best corrosion resistance

and the corrosion resistance of S31035 and C-HRA-5 materials was comparable.