Al—Li—Cu—Mg合金应力腐蚀性能及机理研究

利用恒应变速率方法研究了Al—Li—Cu—Mg合金的应力腐蚀开裂,包括时效条件及外加电位对应力腐蚀的影响,同时研究了试样表面相对氢浓度与外加电位及应力腐蚀时间的关系,实验结果表明,合金的应力腐蚀性能取决于时效条件,其中峰时效条件下最差,自然时效条件下最好,应力腐蚀敏感性及试样表面氢浓度与外加电位有关,阳极电位增加应力腐蚀敏感性,阴极电位低于临界电位时加速应力腐蚀,认为合金在应力腐蚀过程中阳极溶解与氢脆机制联合作用。

STRESS CORROSION PERFORMANCE OF Al-Li-Cu-Mg ALLOY

Studies were made of the influence of aging conditions and applied potentials on the stress corrosion cracking (SCC) susceptibility, for an Al-Li-Cu-Mg alloy by slow strain rate technique. The relationship between the relative hydrogen content on specimen surface and the applied potentials and elapsed time has also been examined. The SCC susceptibility was found to be dependent on aging conditions in which the peak aged condition gave the worst SCC resistance and the natural aged condition had the best one. The SCC susceptibility and sur- face hydrogen content are related to the applied potentials. The anodic potentials increase SCC susceptibility, while the cathodic ones below the critical accelerate SCC. It is considered that both the anodic dissolution and hydrogen embrittlement contribute to SCC.