浸泡温度和时间对海洋结构钛合金耐腐蚀性能的影响

Effect of Immersing Temperature and Duration on Corrosion Resistance of Ti Alloy in Marine Field

为了掌握海洋领域用结构钛合金在服役过程中的腐蚀机制和耐腐蚀性能,研究了浸泡温度和腐蚀时间对近β钛合金Ti-5321腐蚀性能的影响。结果发现,钛合金的微观组织类型对其腐蚀行为存在显著的影响,相比于片层组织,具有等轴β晶粒组织的合金具有更加优异的耐腐蚀性能。随着温度的上升,合金腐蚀电流密度逐渐下降,当温度在40~60℃之间时,腐蚀电流密度几乎不变。这是因为当达到一定温度时,合金表面会快速形成氧化物薄膜,导致腐蚀速率下降。当合金所处温度不变时,随着服役时间的延长,腐蚀电流密度减小,其原因是由于钛合金表面形成了致密的TiO_(2)薄膜,起到了降低合金腐蚀速率的作用。

In order to master the corrosion mechanisms and corrosion resistance of nearβtitanium alloy Ti-5321 used in marine field,the effects of corrosion temperature and time on corrosion performance were investigated.It was found that the microstructures of alloy have a significant impact on its corrosion behavior.Compared with lamellar structure,the equiaxedβgrains microstructure had better corrosion resistance.With the temperature increasing,the corrosion current density of the alloy gradually decreased.When immersed at 40~60℃,the corrosion current density remained stable.This was due to the formation of oxide film at the surface,leading to decreased corrosion rate.When the temperature was unchanged,the corrosion current density decreased with the immersing time prolonging.This was also due to the formation of a dense TiO_(2) film on the surface,which played a role in reducing corrosion rate of the alloy.