Enhancing Both the Mechanical Properties and Hydrogen Embrittlement Resistance of Pipeline Steel Simultaneously Through Cerium Microalloying

The deployment of high‐strength steels for hydrogen transportation pipelines, while economically and technically advantageous, intensifies the critical risk of hydrogen embrittlement. To address the key challenge of balancing strength with hydrogen embrittlement resistance, this study introduces a cerium microalloying strategy that simultaneously enhances both properties in ×80 pipeline steel. Tensile tests demonstrate that the addition of 170 ppm Ce enhances the yield strength and total elongation of ×80 pipeline steel from 587.6 MPa and 16.2% to 618 MPa and 19.5%, respectively. More significantly, the corresponding hydrogen embrittlement index is markedly reduced from 15.8% to 4.0%. Hydrogen permeation analysis reveals that Ce microalloying multiplies the density of irreversible hydrogen traps, thereby decreasing the effective hydrogen diffusion coefficient from 2.8 × 10 −5 to 6.6 × 10 −6 cm 2 /s. Thermal desorption spectrometry further quantifies this effect, showing a substantial increase in hydrogen desorption energy for both reversible and irreversible traps. The strategy successfully improves HE resistance without sacrificing mechanical integrity, which provides a critical theoretical foundation and a feasible material design approach for developing next‐generation pipeline steels with balanced performance.