Xia Lei, Li Yan, Ma Leilei, Zhang Hongmei, Li Na, Jiang Zhengyi
School of Material and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, China.
State Key Laboratory of Metal Material for Marine Equipment and Application, Anshan 114009, China.
Materials (Basel). 2020 Feb 9;13(3):791. doi: 10.3390/ma13030791.
With the introduction of O during oil and gas production, the erosion-corrosion rate of tubing steels increases; the objective of this report is to explore the reason for this. Erosion-corrosion experiments were performed in environments of CO and CO-O, respectively. Macrographs, microstructures, and the compositions of erosion-corrosion scales were investigated using a digital camera, scanning electron microscope (SEM), Kevex-SuperDry energy spectrometer (EDS) and X-ray diffraction (XRD). The results show that the erosion-corrosion products are composed of large FeCO particles and some amorphous product in the CO environment, while they are made up of FeCO, FeO, FeO, and bits of amorphous product in the CO-O environment. The interface between erosion-corrosion scales and the substrate of 3Cr steel is smooth, and Cr enrichment obviously exists in the erosion-corrosion products in the CO condition. However, the erosion-corrosion scale is loose and porous with little Cr enrichment in the CO-O environment, which makes the protectiveness of the erosion-corrosion scale weak, and pitting corrosion occurs. The addition of O may destroy the protective FeCO scale and Cr enrichment in the erosion-corrosion scale, which may be the main reason for the decline in the level of protectiveness of the erosion-corrosion scale, making it weak in terms of preventing the corrosive medium from diffusing to the substrate.
随着在石油和天然气生产过程中引入氧气，油管钢的冲蚀腐蚀速率增加；本报告的目的是探究其原因。分别在CO和CO-O环境中进行了冲蚀腐蚀实验。使用数码相机、扫描电子显微镜（SEM）、Kevex-SuperDry能谱仪（EDS）和X射线衍射仪（XRD）对冲蚀腐蚀产物的宏观形貌、微观结构和成分进行了研究。结果表明，在CO环境中，冲蚀腐蚀产物由大的FeCO颗粒和一些非晶态产物组成，而在CO-O环境中，它们由FeCO、FeO、FeO和少量非晶态产物组成。3Cr钢的冲蚀腐蚀产物层与基体之间的界面光滑，在CO环境下的冲蚀腐蚀产物中明显存在Cr富集。然而，在CO-O环境中，冲蚀腐蚀产物层疏松多孔，Cr富集很少，这使得冲蚀腐蚀产物层的保护性能较弱，从而发生点蚀。氧气的加入可能会破坏具有保护作用的FeCO产物层以及冲蚀腐蚀产物层中的Cr富集，这可能是冲蚀腐蚀产物层保护性能下降的主要原因，使其在阻止腐蚀介质扩散到基体方面能力较弱。
