基于声发射技术的不锈钢应力腐蚀过程研究

摘要

In this paper, the corrosion process of the 304 stainless steel in the acidic NaCl solution is studied by using the electrochemical noise(EN) and acoustic emission(AE) techniques. The AE signals in the corrosion process are clustered based on the K-Means clustering algorithm, and the AE signal characteristics are analyzed through the wavelet packet. It is shown that the stress corrosion cracking(SCC) occurs easily in the experimental system, and the corrosion forms are developed gradually from the localized corrosion to the general corrosion. The AE signal characteristics of the pitting corrosion, the crack and the bubble break-up are quite different during the corrosion process. The AE test results are found to be consistent with the EN test results.%文章研究了304不锈钢试件在酸性NaCl溶液中进行慢应变速率拉伸试验过程中的电化学噪声和声发射特征，提出了基于K-Means 聚类算法的声发射信号聚类分析，并对各聚类信号进行小波包特征提取。研究结果表明：在测试体系中，304不锈钢很容易发生应力腐蚀，其腐蚀形态由局部腐蚀逐渐发展成为全面腐蚀；腐蚀过程中表征点蚀、裂纹和气泡破裂的声发射信号特征差异十分明显；声发射检测结果与电化学噪声检测结果基本一致。