新型航空T-31钛合金导管连接件在模拟服役环境中的抗腐蚀性能研究

使用自行研制的航空导管连接件腐蚀试验系统,研究了新型航空T-31钛合金导管连接件在模拟服役环境中的气密性、油压气密性以及应力腐蚀、表面腐蚀等综合性能.对这种钛合金导管连接件在高温盐水溶液浸泡与烘烤循环条件下的表面腐蚀及应力腐蚀行为进行了评价;初步探讨了在模拟服役环境中,这种钛合金发生腐蚀的机理.并比较研究了导管材料1Cr18Ni9Ti与连接件钛合金在6%NaCl水溶液中的电偶腐蚀敏感性.研究发现,T-31钛合金导管连接件在模拟服役环境中只在应力集中处发生轻微孔蚀,在试验应力水平下,无应力腐蚀倾向,具有良好的耐蚀性能;并证明,腐蚀介质通过钛合金阳极化膜层小孔渗入基体对基体造成轻微腐蚀,试验应力水平未造成孔蚀发生处裂纹形核;电偶腐蚀试验进一步说明1Cr18Ni9Ti / T-31电偶对有很小的电偶腐蚀电流,用它们制备的导管及导管连接件能安全地进行偶接.

Study on Corrosion Resistance of Aircraft Conduit Connector of T-31 Titanium Alloy at Simulated Service Environment

Corrosion resistance,airproof and oilproof property of aircraft conduit connector of T-31 titanium alloy were studied at simulated service environment by a conduit connector corrosion experiment system. The behaviors of surface corrosion and stress corrosion of the connectors were evaluated and the corrosion mechanism was investigated. The slight pitting was found just at stress focus place. The stress corrosion sensitivity of the connector was not observed at experiment stress level. It was proved that corrosion medium infiltrated the hole of anodic oxidation film and made the alloy corrosion slightly. The susceptibility of galvanic corrosion of stainless steels 1Cr18Ni9Ti contacted with titanium alloy T-31 in 6% NaCl solution was studied. It was showed that the galvanic corrosion current of galvanic couple was very low. It was demonstrated that the stainless steels 1Cr18Ni9Ti could be used to make the aircraft conduit to be connected with the connector made with T-31.