TiAI合金阴极腐蚀过程中氢的作用

金属间化合物ＴｉＡ１在各种溶液和熔盐中阴极充氢时，当阴极电流大于临界值后就将发生严重的腐蚀现象这种阴极腐蚀速率随阴极电流增大而线性增加。在恒电住下阴极腐蚀速率远比１０极溶解速率要高在酸性溶液中阴极腐蚀速率最高，碱性溶液中次之，盐溶液中最小；酸中阴极腐蚀机理和碱及盐中的不同，腐蚀产物也不同加入氢复合毒化剂能促进阴极腐蚀。熔盐中阴极腐蚀速率随充氢时间增长而增大

THE EFFECT OF HYDROGEN IN THE CATHODIC CORROSION OF Ti Al Liu Lun(The Center of Testing ,Tianjin Normal University)

The titanium aluminide TiAl can undergo severe corrosion during cathodically charging with hydrogen in various aquevus solusions. The phenomena and mechanism of the cathodic corrosion are investigated. The results show that the rate of the cathodic corrosion under a constant potential is much higher than that of the anodic dissolution under the same potential condition. The rate of the cathodic corrosion under a constant current increases linearly with increasing of the current, and takes the maximum value in the 0.5 M H 2 SO 4 solution, the minimum one in the Na 2 SO 4 _solution, the former is ten times highger than the latter. Local hydride fomation disrupting the surface film during the cathodic polarization is the key step. The mechanism of dissolution of the alloy during cathodic polarization in the H 2SO 4, however, is different from that in the NaOH and Na 2SO 4 solutions. Experiment shows that hydrogen dissolved in the specimen can accelerate the cathodic corrosion.