The effects of material surface characteristics on the morphology and size of calcium carbonate crystals nucleating under cold wall pipe flow conditions were studied. We found that high surface energy materials could accelerate the conversion of crystals from vaterite to calcite, and the crystal size increased. Aragonite was found to be absent throughout the experiment. The deposition of calcium carbonate crystals is a layer-over-layer formation process. In the initial deposition period, the crystals are large and continue to grow until covering the material surface. At subsequent stages, the crystals forming on the existing fouling become much smaller. Studying the influence of material surface on the morphology and size of calcium carbonate crystals is important both for the reasonable selection of industrial materials and for the synthesis of calcium carbonate crystals with certain morphology and size.

To ensure the safety of supercritical CO₂ pipelines and address the limitations of full-scale fracture tests, such as high risk and substantial investment, software for evaluating the crack arrest toughness of CO₂ pipelines containing impurities was developed based on the Battelle Two-Curve Model (BTCM) in this study. The software is programmed in Python (v.3.12.4), with a graphical user interface (GUI) built using PyQt6 (v.6.10.0) and a three-tier architecture design. It integrates the resistance curve model and the decompression wave model. To determine the thermodynamic state of the fluid, a large property database covering pure components and various mixtures is embedded, incorporating state equations such as PR, HEOS, and GERG-2008. The software can generate pressure drop curves, decompression curves, and resistance curves. The pressure plateau can be quickly identified by examining the pressure drop curve. Whether the pipeline can achieve self-crack arrest can be rapidly judged by comparing the positional relationships between the decompression curve and the resistance curve. To verify the accuracy of the software’s calculation results, comparisons were conducted with previous decompression wave experimental data, full-scale burst test data of a CO₂ pipeline, and the international HLP model. The calculation error of the software is within 10%. The development and application of this software provide a convenient, efficient, and accurate practical tool for the calculation of crack arrest toughness and crack arrest evaluation of supercritical CO₂ pipelines.