Intragranular corrosion behavior of 310S austenitic stainless steel in supercritical carbon dioxide environments
Jichun Zou, Shuai Chen, Zhao Shen, Xueli Zhao, Junxuan Gao, Zhihao Wang, Minghao Wang, Kaiyu Cai, Shen Li, Wanhuan Yang, Wanhuan Yang, Weihua Zhong, Wen Yang, Wen Yang
Abstract
The corrosion resistance of 310S austenitic stainless steel in supercritical carbon dioxide (S–CO 2 ) at 500 °C and 25 MPa was evaluated for potential use in small modular reactors (SMRs). Over 3200 h, 310S demonstrated excellent durability, with minimal corrosion-induced weight gain of 0.0490 mg/cm 2 . Combined with multi-scale characterization methods (GIXRD, SEM, EDS, TEM, SAED), it was found that increasing exposure time led to a notable rise in surface roughness, from 0.0102 μm to 0.4968 μm, due to Fe 3 O 4 particle formation and intragranular oxidation, resulting in a distinct dual-layered oxide structure with an inner FeCr 2 O 4 layer. A continuous SiO 2 interface layer, along with a ∼50 nm amorphous carbon layer, effectively prevented carburization within the substrate. These findings highlight 310S stainless steel's suitability for high-temperature S–CO 2 applications, offering a promising candidate material for SMR systems where oxidation and carburization resistance are essential.