摘要
采用慢应变速率试验法(SSRT)就应变速率、极化电位及时效条件的影响等研究了8090铝锂合金薄板在3.5%氯化钠溶中的应力腐蚀行为。其应力腐蚀敏感性随应变速率和极化电位而变化,且存在一个最敏感的应变速率(1×10^(-6)s^(-1))和一个发生应力腐蚀的临界电位(—800 mV,SCE)。8090合金薄板在欠时数状态下对应力腐蚀最敏感,峰时效状态下次之。而过时数状态下则不敏感。根据实验结果和断口形貌特征,认为8090合金薄板的应力腐蚀为阳极活性通道机制,但在强烈渗氢情况下,氢可能成为应力腐蚀的主导因素。
The stress corrosion cracking (SCC) behavior of the AI-Li 8090 alloy sheet has been evaluated by using the slow strain rate technique(SSRT). The 8090 sheet was exposed to 3.5%NaCI solution under potentiostatic conditions and tested at different tensile strain rate. The most susceptible strain rate (1×10^(-6)·s^(-1)) and a critical potential (—800mV, SCE)have been observed. Aging conditions have great influence on the susceptibility to SCC, with underaged temper being the most susceptible, peak-aged temper being less susceptible and overaged temper being non-susceptible. By synthesizing the results and the fractographie characteristics, a conclusion can be drawn that anodic dissolution is generally the main mechanism of SCC. However hydrogen embrittlement may play a dominant role in the cracking mechanism, when hydrogen heavily permeats into the materials.
出处
《中国腐蚀与防护学报》
CAS
CSCD
1992年第1期49-55,共7页
Journal of Chinese Society For Corrosion and Protection