不同流动体系中碳钢磨损腐蚀可比性的研究

Erosion-Corrosion Behavior of Carbon Steel in Different Simulated Flowing Apparatuses

采用管流式和旋转式两种流动模拟装置,研究了碳钢在单、双相流动海水中的磨损腐蚀。结果表明,在相同流速条件下,两种模拟装置所测得的碳钢流动腐蚀速度很难相同,流速不能准确描述流体流动对材料腐蚀的作用。而材料表面近壁处流体力学参数(表面切应力、传质系数)却与材料流动腐蚀本质相关。在保证动量、质量传递相似的条件下,从表面切应力、质量传递系数等参量入手,研究两种装置中实测的腐蚀速度的可比性和关联性是可行的。碳钢磨损腐蚀机理的研究表明:其腐蚀机制与流动模拟装置无关,在流动海水中溶解氧的传质是腐蚀的主要控制因素。

Erosioncorrosion behavior of carbon steel in single and two phases flowing seawater was studied by loop and rotating simulated flowing apparatuses. The results showed that at the same flow velocities the erosioncorrosion rates of carbon steel were very different in the two simulated apparatus, and flow velocity could not accurately describe the effect of fluid flow on the erosioncorrosion. However the nearwall hydrodynamic parameters at the interface of materials, such as surface shear stress and mass transfer coefficient, were correlated in nature with corrosion of carbon steel. It was feasible to deeply investigate the relationship of erosioncorrosion rate in different simulated flowing apparatuses by using nearwall hydrodynamic parameters concerned to corrosion rate under the conditions of same mass and momentum transfer. The study on erosion-corrosion mechanism showed that the mass transfer process of dissolved oxygen in flowing seawater was the dominated factor of corrosion, which was independent of simulated flowing apparatuses.