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As an additive-manufacturing (AM) technique, powder-bed fusion (PBF) shows tremendous potential in both the research and industrial communities. Research on the post-treatment of PBF-prepared products is a hot topic. Hydrogen embrittlement (HE) resistance is a practical necessity, especially in microstructures. Here, the effect of annealing and hot isostatic pressing (HIP) on the properties of PBF technology-printed CoCrFeNiMn high-entropy alloys (HEAs) is investigated. The results show that these two post-thermal treatment approaches can release residual stress (from approximately 338 to 44 MPa) from PBF-printed samples, which is the main reason for declines in hardness (from approximately 211 to 194 HV). In addition, both annealing and HIP can reduce HE sensitivity, thus improving resistance to HE, with elongation increasing by 75.4% and 85.4% after annealing and HIP, respectively. In summary, both post-thermal treatments are of great significance to the development of HEAs with optimized structures and protection against HE, which can contribute to the development of these behaviors during application.

Buried pipelines are prone to deformation under surface displacement, pressure occupation, and/or other actions, resulting in stress concentration. Conducting regular stress detection is an important approach to reducing pipeline accidents. This study performed experiments on measuring the coercivity stress of X80 steel, the most commonly used material for high-pressure large-diameter gas transmission pipelines. The coercivity of the specimen under different stress combinations was measured using the DC-driven coercive force measurement system, and the variation of coercive force with biaxial stress was also analyzed. The modified coercive force-stress expression of the generalized Hooke’s law was proposed; the model for the coercive force-stress relationship of X80 steel under the biaxial stress state was established based on this expression. The study indicates that the coercive force method is reliable for accurately measuring the stress of pipeline steel and evaluating the safety margin of in-service pipelines.