论文部分内容阅读
第三讲中已经提到交变载荷对应力腐蚀的影响。这一讲要举一些例子说明单向和交变载荷造成腐蚀开裂的异同。解释应力腐蚀和解释腐蚀疲劳的机理很相似。交变载荷的作用也是使金属的表面膜破裂,暴露出新鲜的金属与介质反应,导致最后破断。也可能由于氢吸附在金属表面并向金属中扩散引起裂纹传播。但是,如果认为应力腐蚀和腐蚀疲劳的机理完全一致那就错了。阳极溶解控制的应力腐蚀对介质有特殊的要求,体系一定要在活化钝化转变状态。如铁素体钢在硫酸和氯化物溶液中都不发生应力腐蚀,却会发
In the third lecture, the influence of alternating load on stress corrosion has been mentioned. This talk will give some examples of similarities and differences between corrosion and cracking caused by unidirectional and alternating loads. The mechanism for explaining stress corrosion and explaining corrosion fatigue is very similar. Alternating load is also the role of the metal surface film rupture, exposing the reaction of fresh metal and medium, resulting in the final rupture. It is also possible that cracks propagate due to hydrogen adsorbed on the metal surface and diffused into the metal. However, it is wrong to assume that the mechanisms of stress corrosion and corrosion fatigue are exactly the same. Anodic dissolution of the stress corrosion control of the media have special requirements, the system must be activated in the passivation change state. Such as ferritic steel in the sulfuric acid and chloride solution are not stress corrosion, but will send