January 2018: Dr Jianqiang Zhang, "(i) Minor alloying elements play big roles on corrosion resistance"
“Effects of Si, Al and Ti on corrosion of Ni-20Cr and Ni-30Cr alloys in Ar-20CO2 at 700 °C”
by T. D. Nguyen, JQ Zhang and D. J. Young
The increasing demand for higher power efficiency and the application of a novel oxy-fuel combustion technology in coal-fired power generation lead to higher operating temperatures, and Ni-base alloys are therefore required. However, corrosion behaviour of Ni-Cr binary alloys is not good in CO2-rich gas at high temperatures even by increasing the Cr content to 30 wt.%. The aim of this work is to investigate influences of minor alloying elements (Si, Al, Ti) on corrosion behaviour of Ni-20Cr and Ni-30Cr alloys in dry CO2 at 700 oC. These additions significantly increase the oxidation resistance by forming additional protective scale layers of SiO2, Al2O3 or TiO2.
Read the full paper, as published in Corrosion Science (Volume 130, January 2018, Pages 161-176).