流动场作用下管道材料的腐蚀产物膜破损机理及冲蚀临界特性研究

The erosion-corrosion behaviors and its critical characteristics of 20# carbon steel and incoloy825 steel under the interaction of flow field and corrosion product film were investigated in NH4HS environment by using erosion-corrosion experiments, electrochemical measurement technology and CFD simulation technology. Through the systematic study of the influence of various factors on the characteristics of corrosion product film and erosion-corrosion behaviors of pipeline materials, the relationships among the characteristics of corrosion product film, factors and localized corrosion behaviors were built and the correlation of localized corrosion nucleation, growth of metals and damage behavior of corrosion product film in NH4HS solution system was further illustrated. This work was devoted to developing the erosion-corrosion theories of pipeline in the medium solution containing NH4HS, revealing the initial stage, development process of the damage behavior of corrosion product film of pipeline materials under flow field and its essential cause, elucidating the damage mechanism of corrosion product and influence mechanism of erosion- corrosion failure of pipeline under the interaction of flow field and corrosion product film. This will establish a theoretical basis and technical support for pipeline safety and engineering material selection, design and protection.

本项目利用冲蚀实验，电化学测试技术及CFD仿真技术，开展管道材料20#钢和incoloy825钢在NH4HS(硫氢化铵)环境介质中流动场-腐蚀产物膜交互作用下的冲蚀行为规律及其临界特性的研究。通过系统研究各因素对管道材料的腐蚀产物膜特性与冲蚀行为的影响，建立腐蚀产物膜特性、影响因素和局部腐蚀行为三者之间的关系，并进一步阐明在NH4HS介质体系下金属局部腐蚀形核、发展与腐蚀产物膜破损行为的相关性。发展在含NH4HS介质体系中的管道冲蚀理论，揭示流动场作用下管道材料腐蚀产物膜破损的起始、发展全过程及其本质原因，阐释腐蚀产物的破损机理及流动场/腐蚀产物膜的交互作用对管道冲蚀失效的影响机制，为管道的安全使用及工程选材、设计与防护奠定理论基础。

近年来，流体管道常承受流体劣质化、工况苛刻化、长周期运行，由此引发的管道腐蚀失效事故明显增多。冲蚀是威胁管道安全与使用寿命的主要失效形式之一，特别是含腐蚀性介质的多相流介质输送系统，涉及多相流动、冷却相变、传热传质等过程，在复杂流动环境下极易引发压力管道冲蚀穿孔。因此，开展多相流冲蚀研究对流体管道的防护具有重要意义。.本课题研究了模拟工况下各因素对碳钢和incoloy825钢在NH4HS和NH4Cl介质中的冲蚀行为及其电化学行为的影响，通过采用冲刷腐蚀实验，电化学技术及CFD技术手段深入分析了腐蚀产物膜与流动场间的交互作用，解析了流动场作用下管道材料腐蚀产物膜发生破损的内在原因，获得相关的科研成果。并基于以上技术，研究了冲蚀临界特性行为规律，获得了相关的数据。这为管道系统的冲蚀损伤防护提供了理论依据，该研究系统地认识了流动场作用下管道材料腐蚀产物膜破损-冲蚀失效机制，为管道的腐蚀防护工作及安全预测评价提供了相关借鉴。