Compatibility study between CLF-1 steel and HCCB TBM Helium gas medium for engineering qualification

Focusing on engineering qualification, a compatibility test between CN HCCB-TBM structural material CLF-1 steel and cooling gas medium (He + 30 ppm H 2 ) is presented in this study. The CLF-1 specimens are contacted with a mixed gas at a temperature of 823 K and pressure of 8 MPa for >3000 h. Tensile tests, Charpy impact tests, microstructure analysis, and surface observations are performed on samples after the heating and compared with those of the as-received specimen. Compared results indicate that although a corrosion layer is observed on the surface of the samples under SEM, the tensile and Charpy impact tests show a limited impact on YS, UTS, and DBTT by the mixed gas.