Q235钢板局部腐蚀声发射信号特性研究  

Research on acoustic emission signal characteristics of local corrosion on Q235 steel

作　　者：于洋[1] 杨平[1] 杨理践[1] 梁春宴 

机构地区：[1]沈阳工业大学信息科学与工程学院,沈阳110870 [2]中国能源建设集团沈阳电力机械总厂有限公司,沈阳110026

出　　处：《声学学报》2015年第4期546-554,共9页Acta Acustica

基　　金：中国辽宁省教育厅创新团队项目(LT2010082)资助

摘　　要：为解决腐蚀声发射源特征提取和识别的难题,直接从理论上证明了腐蚀声发射监测的有效性并推导出声发射信号特征。气泡破裂声发射信号幅值近似与气泡半径平方和液位高度成正比,频率与气泡半径成反比;钢板及其腐蚀产物开裂声发射信号幅值与开裂位置局部应力强度成正比,频率与裂纹扩展速度成正比,与裂纹扩展距离成反比。用低频和高频两套声发射系统,同时长时间监测Q235钢板在10%FeCl_3·6H_2O、10%FeCl_3·6H_2O加0.01 mol/L HCl混合液、5%CuSO_4·5H_2O溶液中的腐蚀情况,辅以监测钢板及钢板腐蚀产物开裂作为验证实验。通过对声发射信号的参数及谱分析,得出不同声发射源可以通过撞击数及功率谱在频域的分布来有效区分。实验结果与理论分析相吻合,研究结果对腐蚀声发射监测技术具有重要指导意义。To solve the problem of corrosion acoustic emission （AE） source feature extraction and recognition, the AE detection validation and the amplitude-frequency characteristics were derived in theory. The amplitude of AE signal generated by bubble burst is proportional to its radius square and the liquid level, while the AE signal frequency is inversely proportional to the bubble radius. The AE signal amplitude of the steel and the steel corrosion product cracking is proportional to the local stress, and the AE signal frequency is proportional to the crack propagation velocity and inversely proportional to the crack propagation distance. Three Q235 specimens were separately immersed in the solution of 10%FeCla.6H20, 10%FeC13.6H20 with 0.01 mol/L HCL and 5%CuSO4-5H20. The AE systems with high frequency and low frequency were used to detect the whole corrosion process AE signals. The AE signals of Q235 steel and the steel corrosion products cracking were detected as the verification experiment. The AE signals from different sources could be distinguished by AE hits count and the power spectrum. It is coincident with theoretical analysis. These conclusions have significant guidance for the corrosion detection and evaluation by on-line acoustic emission detecting.

关 键 词：声发射信号 声发射源 裂纹扩展 应力强度 信号幅值 成反比 声发射系统 声发射监测 特征提取 腐蚀产物 

分 类 号：TG174.3[金属学及工艺—金属表面处理]