Inclusions are very often founded in the centre of thickness in hot-rolled pipeline steel. In this research, the role of these inclusions on hydrogen diffusion, accumulation and distribution in pipeline steel is studied using the electrochemical permeation and visualisation experiments. While the permeation experiment estimates the parameters of the diffusion process, the visualisation experiment reveals the diffusion pathway in the steel microstructure. Results from the permeation test allowed to show that the steel samples selected from the segregation zone at the mid-layer of thickness have higher permeability and effective diffusion coefficient than samples from the top-layer. Also, the hydrogen visualisation results permit to reveal an increased discharge of hydrogen around inclusions as represented by a pattern of superimposed white particles. Moreover, the calculated diffusion parameters also allowed us to establish that the density of hydrogen traps in mid-layer was lower than top-layer of the steel.

中文翻译：

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热轧管中扩散位点的可视化和氢陷阱的测量

夹杂物经常出现在热轧管线钢的厚度中心。本研究通过电化学渗透和可视化实验研究了这些夹杂物对管线钢中氢扩散、积累和分布的作用。渗透实验估计了扩散过程的参数，而可视化实验则揭示了钢微观结构中的扩散路径。渗透试验结果表明，从厚度中间层偏析区选取的钢样比顶层样品具有更高的渗透率和有效扩散系数。还，氢可视化结果可以揭示包裹体周围的氢排放增加，如叠加的白色颗粒图案所示。此外，计算的扩散参数还使我们能够确定中间层的氢陷阱密度低于钢的顶层。