With the development of modern industrial technology, there is an increasingly urgent need for the preparation of high-strength and high-performance coatings on the surface of traditional metal materials

In the present work, a series of Sm³⁺ doped transparent strontium aluminate glasses with the composition Al₂O₃-(3-x)SrO: xSm³⁺ (x = 0, 0.01, 0.03, 0.06, 0.1, 0.2) were fabricated by a containerless process using an aerodynamic levitation furnace. The structural characteristics, density, Vicker’s hardness, and thermal and spectroscopic behaviors of these glasses were investigated. All the glasses exhibit excellent thermal stabilities (T_g ≥ 792 °C) and the glass-forming ability is enhanced with the increasing content of Sm³⁺. The emission spectra recorded under an excitation of 404 nm show four emission transitions as a result of ⁴G_5/2 translated to the lower states of ⁶H_5/2, ⁶H_7/2, ⁶H_9/2, and ⁶H_11/2, and a bright orange-reddish luminescence can be observed in Al₂O₃-(3-x)SrO: xSm³⁺ glasses. The high thermal stability, good glass-forming ability and excellent hardness provide new options for the development of visible orange-reddish lasers and smart photoluminescent glass coating materials.

High-velocity oxygen fuel (HVOF)-sprayed amorphous alloy coatings usually have advantages of a dense structure that improve their resistance to corrosion, wear, and fatigue in the substrate. The flame flow characteristics and particle behaviors during the spray process have a significant influence on the amorphous coating structure and properties. In this study, a computational fluid dynamics model is enforced to analyze the flame flow and Fe-based amorphous alloy particle behavior in an HVOF spray process. The flame flow temperature, velocity characteristics, and the Fe₄₈Cr₁₅Mo₁₄C₁₅B₆Y₂ Fe-based amorphous alloy particles’ velocities, temperatures, flight trajectories, and mass concentration distribution characteristics are simulated. Moreover, the effects of the oxygen/fuel ratio, particle morphology parameter, particle-injection rate, and angle on the particle behavior are also investigated. Judging from the simulation results, the optimum amorphous alloy particle size varies between 20 and 30 μm, the shape factor is within the range of 0.9–1, the optimum O/F ratio is 3.4, the optimum injection angle is 45°, and the optimum injection rate is 10 m/s. With these conditions, most of the particles settled toward the centerline of the spray gun and are in a semisolid or solid state before affecting the substrate, giving the materials optimal coating structure and performance.

This paper presents a full-scale deep-water steel catenary riser fatigue test system. The proposed system can carry out fatigue tests on steel catenary risers, hoses, and subsea pipelines up to 21 m in length, ranging from 8 to 24 inches in diameter. The test system was realized by mechanical loading with loading control systems, and could carry out axial tension and compression, bending moment, torsion, and internal pressure to simulate all load types on deep-water steel catenary risers or subsea pipelines. The counterforce was sustained by a counterforce frame. Through mechanical simulation analysis, the authors determined the size of the counterforce frame and designed the connection form of the counterforce frame and loading system. According to the required loading capacity, the appropriate cylinder thickness and diameter were obtained through calculation. After the design and construction of the test system, the authors designed a fatigue test to confirm the loading capacity and accuracy of the test system. The authors performed full-scale testing to assess the fatigue performance of pipe-to-pipe mainline 5G girth welds fabricated to BS 7608. This test was designed according to the stress level of pipelines in the Lingshui 17-2 gas field, and the test results were compared with the calculation results of the S–N curve.