论文部分内容阅读
2219铝合金可作为火箭燃料贮箱的主要结构材料,搅拌摩擦焊是其理想的焊接方法之一。目前对2219铝合金搅拌摩擦焊接头在酸性介质中的腐蚀问题鲜有报道。该文采用极化曲线和浸泡腐蚀实验对2219-T8铝合金搅拌摩擦焊接头在0.5mol/L NaCl溶液(pH 2)中的腐蚀行为进行了研究,并通过光学轮廓仪分析了腐蚀形貌、腐蚀深度和密度。结果表明:与母材相比,热影响区的腐蚀行为出现了分化,远缝区耐蚀性能下降,而近缝区耐蚀性能提高;热机械影响区和焊核区的耐蚀性能提高。由于母材和热影响区远缝区的腐蚀电位更负,对接头其他区域起到了阴极保护作用。与中性介质相比,酸性介质中主要的阴极反应为析氢反应,降低了接头各区的腐蚀电位和点蚀电位。
2219 aluminum alloy can be used as the main structural material of rocket fuel tank, friction stir welding is one of the ideal welding methods. At present, 2292 aluminum alloy friction stir welded joints in the acid medium corrosion rarely reported. In this paper, the corrosion behavior of 2219-T8 aluminum alloy friction stir welded joint in 0.5 mol / L NaCl solution (pH 2) was investigated by polarization curve and immersion corrosion test. The corrosion morphology, Corrosion depth and density. The results show that compared with the base metal, the corrosion behavior of the HAZ is differentiated, the corrosion resistance of the far zone is decreased, while the corrosion resistance of the near zone is enhanced, while the corrosion resistance of the HAZ and the weld zone is enhanced. Since the corrosion potential of the base material and the heat-affected zone in the far-seam area is more negative, cathode protection is provided to other areas of the joint. Compared with neutral medium, the main cathodic reaction in acidic medium is hydrogen evolution reaction, which reduces the corrosion potential and pitting potential of the joints.