Combined Effect of Cold Working and Al Content on Oxidation Behavior of Ni-Base Alloys at 900 °C and 1000 °C

Journal article, 2025

Ni-base alloys are the most commonly used type of construction materials, especially in high-temperature applications. It is widely known that the high-temperature corrosion resistance of these types of materials depends on their chemical composition. Specifically, the Cr and Al content plays an important role. The formation of an alumina scale (aluminum oxide) is the most desired phenomenon because it provides the best protection against high-temperature oxidation among all known types of oxide scale. The effect of the Al content of Ni-base alloys on the transition from internal to external oxide scale formation has been widely investigated. It is also known that cold working can sufficiently affect the oxidation kinetics. However, there is a lack of knowledge about the synergetic effect of the Al content and cold working on the transition from internal to external scaling. Therefore, the objective of the present study is to explore the interaction between the Al content of the NiCrAl base alloy and its surface finish to evaluate the extent of a positive effect of cold working that could compensate for an insufficient Al content in the Al alloy from external Al2O3. To elucidate this effect, three commercially available Ni-base superalloys, namely IN 617, IN 602 CA, and IN 692 with different amounts of Al and different cold-worked surfaces, were investigated during air oxidation at 900 °C and 1000 °C up to 48 h. The results showed that cold grinding pronounced the formation of alumina scale in the case of alloys with insufficient Al content. The reasons for such an effect have been elucidated and are explained.