304不锈钢两相流冲蚀腐蚀的实验研究

Experimental study on erosion-corrosion of 304 stainless steel under two-phase flow condition

通过液固两相流冲蚀腐蚀实验,辅以电化学测量方法,研究了不同冲角(45°,60°,90°)、冲蚀时间、流体性质(有无氯离子)等因素对304不锈钢冲蚀腐蚀的影响。实验结果表明,模拟海水(NaCl的质量分数为3. 5%)中的氯离子极大促进了颗粒对材料的冲蚀效果,45°冲角下氯离子对冲蚀腐蚀的促进作用最为显著,其次是90°和60°冲角。金相显微照片显示了冲蚀时间对样品表面形貌的影响。在3个不同冲角冲蚀腐蚀下,电化学测试表明,材料钝化膜随冲蚀腐蚀时间增加而变得不完整是不锈钢材料抗腐蚀性能下降的主要原因。

In this study,the erosion-corrosion of 304 stainless steel was investigated by liquid-solid twophase jet impingement experiment,combined with the electrochemical measurement.The influence factors of different impact angles(45°,60°,90°),erosion time and fluid properties(with or without chloride ion)on erosion-corrosion of 304 stainless steel were studied.The results show that the chloride ion in the simulated seawater(mass fraction of NaCl is 3.5%)can significantly promote the erosion of the material.Under 45°impact angle,the promoting effect of erosion-corrosion due to the chloride ion is the most significant,followed by 90°and 60°impact angles.The metallographic microscope image shows the effect of erosion time on the surface morphology of the sample.The electrochemical test shows that,at the three different impact angles,the material passivation film becomes incomplete with increasing erosion time.The incomplete passivation film is the main reason for the decrease in corrosion resistance of stainless steel material.