Influence of flow conditions on the corrosion of AISI 304L stainless steel
Influence of flow conditions on the corrosion of AISI 304L stainless steel
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DOI：
10.1016/s0043-1648(03)00562-3
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发表时间：
2004-03
期刊：
影响因子：
5
通讯作者：
J. Wharton;R. Wood
中科院分区：
文献类型：
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作者：
J. Wharton;R. Wood
AISI 304L 不锈钢的流体动力学和电化学噪声测量 (ENM) 在内径 28 毫米的管道测试段中进行，适用于从层流到湍流的一系列流态。通过测试段的平均流速控制在0.04、0.07、0.11、0.36、1.8和2.7ms−1，分别相当于雷诺数1000、2000、3000、10000、50000和75000。采用标准流体动力学参数来表征和评估氧气的传质速率和通过湍流到金属/溶液界面的动量传递之间复杂的相互关系。对于 AISI 304L 不锈钢，点蚀通常以亚稳态凹坑的形式发生，这些凹坑要么在达到稳定之前重新钝化，要么生长成为稳定凹坑。在所有流动状态下，亚稳态点蚀都很明显。流体流动，无论是层流还是湍流，对亚稳态点蚀事件的成核速率几乎没有总体影响。相反，在过渡到湍流之前的层流过程中，稳定的凹坑生长最为明显，并且接近临界速度（~1.5ms−1）。
Hydrodynamic and electrochemical noise measurements (ENMs), of AISI 304L stainless steel, were made in a pipe test section of 28mm inside diameter for a range of flow regimes from laminar to turbulent. Mean flow velocities through the test section were controlled at 0.04, 0.07, 0.11, 0.36, 1.8 and 2.7ms−1, equivalent to Reynolds numbers of 1000, 2000, 3000, 10000, 50000 and 75000, respectively. Standard hydrodynamic parameters were employed to characterise and evaluate the complex interrelationship between the mass transfer rate of oxygen and momentum transfer through turbulence to the metal/solution interface. For AISI 304L stainless steel, pitting typically occurs in the form of metastable pits which either repassivated before achieving stability or grow to become stable pits. Metastable pitting was evident under all flow regimes. The fluid flow, whether laminar or turbulent, had little overall effect on the nucleation rates of metastable pitting events. Conversely, stable pit growth was most evident during laminar flow immediately before the transition to turbulent flow and close to the critical velocity (∼1.5ms−1).