应力腐蚀破裂过程中的声发射监测与分析

AE MONITORING AND ANALYSIS DURING STRESS CORROSION CRACKING

在慢应变速率条件下,对16MnR 钢的应力腐蚀过程进行了声发射监测,在应力腐蚀过程中利用声发射系统(3000/3004,USA)测定了声发射计数,计数率,总能量和总计数等参量。根据宽带连续检测所记录的声发射信号数据,得到了对应于不同声发射信号波形和频谱的情况。试验结果表明,16MnR 钢在20℃的3.5%NaCl 水溶液的应力腐蚀条件下所产生的声发射信号要比在空气中丰富。根据声发射数据和统计参量确定开裂点,同时可以描述应力腐蚀过程。根据典型声发射信号的波形和频谱特征,有可能判断应力腐蚀过程中声发射源的类型。上述声发射监测结果,经断口扫描电镜分析得到了验证。

Acoustic Emission(AE)monitoring was performed during stress corrosion cracking(SCC)process on 16MnR steel in the case slow strain rate.AE paremeters about event count,count rate,total energy and total count were measured during SCC process by used of AE 3000/3004 USAsystem.Information on AE frequency and waveform characteristics,which arc related to thedifferent AE sources,has been obtained by broadband detection and data recording of AE sign-als.The experiment results show that AE signals of 16MnR steel in corrosion cnvironment of3.5% NaCl solution at 20℃ are more abundant than that in air.The crack opening point can bedetermined by AE responses which can also be used to describe the SCC process.The kind of AE sources during the SCC process can be judged by the features of AE wave-form and frequency spectrum.The results of AE detection above mentioned have been verified by electron fractography an-alysis.