Although different forms of renewable energy sources are in expansion, the oil and natural gas industry remains essential, maintaining its demand for more efficient methods for product transportation. The most productive and safe way is the flow through pipelines. However, pipeline usage directly involves several wear mechanisms, which contribute to pipeline degradation and, consequently, the need for repairs and maintenance shutdowns, implying in heavy financial impact in the entire industrial chain of supply. An economical and feasible solution to mitigate wear is to protect equipment with metallic coatings. Through this technique, engineers can keep the more noble—and expensive—metals only in regions where their chemical and mechanics proprieties are needed. Various processes may be industrially used for coating, presenting different levels of productivity, quality, and required investment. Among the arc welding processes, the most used for coating applications against wear and corrosion is the tungsten inert gas (TIG) process. The laser coating process, or laser metal deposition (LMD), a process concurrent to TIG, can apply such coatings with high precision and reproducibility, minimizing dilution, distortions, lack of fusion, and the formation of a large heat affected zones; however, results may vary. The present work evaluates two dilution-equivalent Inconel 625 coatings through rubber disk tribological testing, microhardness measurements, and worn surface analysis by scanning electron microscopy via energy dispersive x-ray analysis. Each coating was manufactured by one of the mentioned processes, LMD or TIG, with three replicates of each process to observe its repeatability. For the laser manufactured coating, microhardness values averaged to 247 HV, while TIG's average stayed at 218 HV. Volumetric loss due to wear testing behaved differently, with higher values about 16.3% more for TIG when compared to laser coating. The differences between microhardness values and volume losses are explained by crossing information from each coating's cross-section microscopy and worn surface, as well as each process parameterization and nature. In conclusion, LMD coating presented itself as the more efficient process; such a result, in parallel with the continuous advance in laser sources technology, makes a significant contribution to LMD consolidation as the pipeline coating process and a case study with a tribological comparison between two frequently applied processes.

中文翻译：

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通过激光金属沉积和钨惰性气体焊接工艺沉积的 Inconel 625 涂层的摩擦学比较

尽管不同形式的可再生能源正在扩张，但石油和天然气行业仍然必不可少，保持其对更有效的产品运输方法的需求。最高效和最安全的方式是通过管道流动。然而，管道使用直接涉及多种磨损机制，这些机制会导致管道退化，因此需要维修和维护停机，这意味着对整个供应链的财务影响很大。减轻磨损的经济可行的解决方案是用金属涂层保护设备。通过这种技术，工程师可以只在需要其化学和力学特性的地区保留更贵重的金属。工业上可以使用各种工艺进行涂层，呈现不同水平的生产力、质量和所需投资。在弧焊工艺中，最常用于抗磨损和腐蚀的涂层应用是钨惰性气体 (TIG) 工艺。激光涂层工艺或激光金属沉积 (LMD) 工艺是与 TIG 并行的工艺，可以以高精度和可重复性应用此类涂层，最大限度地减少稀释、变形、未熔合和大热影响区的形成；然而，结果可能会有所不同。目前的工作通过橡胶盘摩擦学测试、显微硬度测量和通过能量色散 X 射线分析的扫描电子显微镜分析磨损表面来评估两种稀释等效的 Inconel 625 涂层。每个涂层均由上述工艺之一制造，LMD 或 TIG，每个过程重复 3 次，以观察其可重复性。对于激光制造的涂层，显微硬度值平均为 247 HV，而 TIG 的平均值保持在 218 HV。由于磨损测试导致的体积损失表现不同，与激光涂层相比，TIG 的更高值高出约 16.3%。显微硬度值和体积损失之间的差异可以通过来自每个涂层的横截面显微镜和磨损表面的交叉信息以及每个过程参数化和性质来解释。总而言之，LMD 涂层本身是一种更有效的工艺；这样的结果，伴随着激光源技术的不断进步，