论文部分内容阅读
本文用DCB试样研究了LC4高强度铝合金在pH=6～6.5,35℃±1℃的3.5％NaCl溶液中应力腐蚀断裂机理。 文中分析了断口表面的特征,并且指出靠近裂纹尖端的断口表面上被一层薄的钝化膜所复盖。它是一种非常有效的防止氢进入金属的阻挡层。 用金相跟踪照相的方法得到的应力腐蚀断裂试验结果证实裂纹尖端前沿的塑性区大小取决于裂纹尖端的K_1,而不取决于其它因素。 用恒电位技术得到的IgV—ψ曲线,表明阴极极化作用会抑制裂纹扩展,而阳极极化作用会促进裂纹扩展速率。 作者论证了LC4铝合金在试验条件下的裂纹扩展不是由于氢脆引起的。
In this paper, the stress corrosion cracking mechanism of LC4 high strength aluminum alloy in 3.5% NaCl solution with pH = 6 ~ 6.5, 35 ℃ ± 1 ℃ was studied by DCB sample. In this paper, the characteristics of the fracture surface are analyzed, and the fracture surface close to the crack tip is covered with a thin passivation film. It is a very effective barrier against the ingress of hydrogen into the metal. The result of stress corrosion cracking test by metallographic tracking method confirms that the plastic zone size at the tip of the crack tip depends on K 1 at the tip of the crack and does not depend on other factors. The IgV-ψ curve obtained with potentiostatic technique shows that cathodic polarization suppresses crack propagation, whereas anodic polarization accelerates the crack propagation rate. The authors demonstrate that the crack growth of LC4 aluminum alloy under the experimental conditions is not caused by hydrogen embrittlement.