【作者】 宋曰海；

【导师】 郭忠诚；

【作者基本信息】 昆明理工大学 ， 材料学， 2003， 硕士

【摘要】 目前常用的保护钢铁设备的牺牲阳极材料有铝基合金、锌基合金和镁基合金三大类。牺牲阳极的性能主要由材料的化学成分和组织结构决定。铝基阳极比重小、电流效率高、发生电量大、对钢铁驱动电位适中、来源丰富。是一种迅速发展起来的新型牺牲阳极材料。锌基阳极比重大、发生电量小、对钢铁的驱动电位不高，且在高温条件下易于极化，一般用于电阻率较低的环境。镁基阳极电流效率低、对钢铁驱动电位大（易于过保护），只用于电阻率较高的土壤环境。 通过实验，根据在常温海水实验数据及性能测试结果，经过综合分析，确定了阳极材料合金元素最佳含量范围，测试了牺牲阳极材料的电化学性能，并分析了合金元素的作用。在铝合金中，镉的加入能促使锌均匀分布，减少锌、铜、铟偏析，改善阳极腐蚀状况，如镉量过高时，将析出新相，产生“过活化”作用，增大自腐蚀，加入量一般控制在0.01％左右。若添加0.5％-4％的镁可显著提高其电流效率，尤其存在微量锡时，效果更为明显，因为锡与镁之间具有匹配作用，锡的量应控制在0.01～0.1％之间。硅最显著的作用是改善铝合金的铸造性能，但对合金的抗蚀性和可焊性有损害。 通过正交实验法探索出Al-Zn-In-Cd牺牲阳极材料的最佳成分比，实验证明：Al-3.5Zn-0.02In-0.01Cd牺牲阳极材料的电化学性能各项指标均达到或超过国家标准，腐蚀产物容易脱落，表面溶解均匀，电位较负，较稳定，在0～20mA电流范围内，无钝化现象出现，阳极一直处于活化状态，组织分布较为均匀，由于In和Cd两者之间达到良好的匹配效果，表面溶解均匀，产物容易脱落，为最佳组成阳极材料。 实验表明：Al-Zn-In-Sn-Re、Al-Zn-In-Sn-Mg-Re牺牲阳极材料的电流效率都较高，金相组织分布较为均匀，Re含量越高，起始电位越高，电流效率越高，试样表面溶解均匀，为理想的牺牲阳极材料。Al-4Zn-0.03In-0.03Ti-1Mg，Al-7Zn-0.1Sn-0.03Ti-1Mg，Al-3Zn-0.03In-0.015Cd-1.25Mn，Al-7Zn-0.1Sn-0.015Cd几种阳极材料，Ti元素最显著的作用是用来细化固溶体型合金的固熔体组织。Al中加少量Ti就能形成TiAl₃，而具有高熔点的TiAl₃在合金结晶前就已形成了大量细小的晶粒而起到外来晶核的作用，使铝合金组织得到细化，从而使阳极溶解更均匀。 另外，添加少量Ti能防止铸造的热裂现象发生，减小阳极晶间腐蚀倾向。锡溶昆明理工大学硕士研究生学位论文摘要于铝中形成固溶体，其溶解度仅有0.07%左右，以Sno的方式进入铝表面氧化膜，破坏其钝性，可以降低铝电位。 研究了Zn一Al一Cd和Zn-AI一Mn两类阳极材料。合金元素Al的含量不宜过高，才和Cd配合较好效果，合金元素铝、锅细化了锌合金的晶粒，抑制了杂质的影响，从而使锌阳极的性能得到较大的改善，加入Mn元素可以活化金属，提高电流效率，此类合金阳极的电位和发生电流稳定，阳极极化小，电流效率高，溶解均匀，金相组织均匀，腐蚀产物疏松易脱落，锰含量越高，晶粒越细小。但Mn含量升高，电流效率有所降低，再增大，电流效率有升高，因而要控制在0.1%左右为最佳。更多还原

【Abstract】 At present, the sacrificial anode materials used for the protection of iron and steel, which are based of aluminum, zinc and magnesium alloy. The performance of sacrificial anode is determined by it’s chemical constitution and structure. The Al -based anode with low density, high current efficiency, much power generated, moderate potential applied to iron and steel, is a rapidly developed new sacrificial anode material. Zn-based anode with high density, less power generated, low potential, applied to iron and steel, ease to polarize at high temperature, is usually used in the environment of low electrical resistance. Mg-based anode with low current efficiency, high potential applied to iron and steel (ease to over-protect), is only used in soil environment of high electrical resistance.In this experimental according to data from salt water test of normal temperature and results of performance test, through comprehensive analysis, the premium content range of alloy of the sacrificial materials is determined. The electrochemical performance of sacrificial anode material is tested and the function of element in the alloy is analyzed. In Al alloy, the cadmium added can improve the uniform distribution of Zn, decrease segregation of Zn, between the corrosion condition of anode, but if the content of Cd is high, It will segregate new phase, produce the effect of" over-activation ", increase self-corrosion, usually the content of Cd is 0.01 percent. Mg(0.5~0.4 percent) can notably increase it’s current efficiency, especially there is little Sn, the influence is more obvious, because Sn and Mg have good matching function. The content of Sn is usually 0.01-0.1 percent. The most important effect of Si is to better the cast performance of Al alloy, but have detrimental effect on the performance of anti-corrosion and weld of the alloy.By orthogonal testing method, the premium element content of Al-Zn-In-Cd is determined. The results of test are as follows, when the content of Al-3.5Zn-0.02In-0.01Cd, the every index of electrochemical performance of the sacrificial anode material can reach or overpass national standard. The product of corrosion is easy to remove, the surface dissolve uniformly, and the potential is much more negative and stable, and current density at the range of 0~20mA. There is passivity. The anode is kept in active condition, the distribution of structure is uniform, due to the good matching of Zn and Cd, the surface dissolve uniformly, the produce of corrosion is easy to remove, so it is the most ideal constitution of sacrificial material.By experimenting, the Al-Zn-In-Sn-Re and Al-Zn-In-Mg-Re sacrificial anode material having high current efficiency, good uniformity of distribution of metallurgical phase and the more much content of Re, the higher start potential and current efficiency, and the more uniform of surface dissolve. So, they are ideal sacrificial anode material.In the following anode material Al-4Zn-0.03In-0.03Ti-lMg, Al-7Zn-0.1Sn-0.03Ti-lMg, Al-3Zn-0.03In-0.015Cd-l.25Mn, and Al-7Zn-0.1Sn-0.015Cd, the most important function of Ti is to make the structure of solid solution refine. Al forms TiAh with added Ti, which have high meting point and fine crystalline, can act as crystalline core to refine. The structure of Al alloy, and make the resolve of anode uniform.In addition, the small amount Ti added, can prevent the heat check during casting, decrease the corrosion between crystalline in the anode. Sn melts in the Al to form solid solution, with the degree of solvent at about 0.03 percent, and enters the surface oxide film of Al in the form of SnO, and destroys it’s passivity, decrease the potential of Al.Two kinds of anode material, Zn-Al-Cd and Zn-Al-Mn, are explored in the experiment. The content of Al is not suited too high, only so, Al and Cd is matching infection well. Al and Cd in the alloy make the crystalline of Zn alloy fine, inhibit the influence of impurity, and accordingly improve the performance of Zn anode. Mn active metal, increases current efficiency. This kind o更多还原