基于大气腐蚀检测仪的锌在大气环境中腐蚀行为的研究
发布时间：2018-08-04 20:53
【摘要】：由于锌具有低的腐蚀电位和腐蚀速率,其成为钢铁腐蚀防护的理想材料。但在不同地区,锌涂层的防腐效果千差万别,寿命长短不一。为寻找这些差别原因,以往通过对经长期暴露试样腐蚀消耗量的测量、腐蚀产物的解剖观察等方法,了解科学研究所需的信息。但是,受大气环境复杂性和腐蚀失效周期过长的限制,这种方法的有效性和时效性屡屡受到诟病。至今,还未能充分掌握锌涂层在自然大气中的腐蚀失效规律。现有的实验室模拟环境加速腐蚀试验及其它间接的评价手段,所获数据量少、不能充分反映锌的大气腐蚀随时间的变化过程,给研究锌的大气腐蚀带来极大困难,且易产生大的误差。开展长期、连续、实时、原位的评价成为研究金属在大气环境中腐蚀的大势所趋。因此,本文针对锌的大气环境腐蚀开发了新型大气腐蚀检测仪(ACM)。该ACM选用了惰性碳膜做阴极材料,有效地消除了传统ACM中阴极材料的同步腐蚀引起的电化学性能改变,三层叠加结构使得电偶的阴极和阳极材料分别处在两个平行平面上,避免了阳极腐蚀产物对阴极材料表面的影响,提高了传感器的一致性和使用寿命。配套开发的ACM检测仪采用了固态电池和太阳能电池板的双供电模式,并利用GPRS实现了数据的远程传输,减少了传统暴露试样法人工操作带来的信息丢失和数据误差,保证了锌在真实大气环境中腐蚀数据的稳定。经野外环境、模拟环境及锌表面改性等试验表明,该ACM能够满足长时、连续、实时和原位的腐蚀检测工作,是研究锌在大气环境中的腐蚀,掌握锌的大气腐蚀规律的有效手段。多因子循环复合实验是模拟大气环境腐蚀且具有加速性和重现性的重要手段,是研究金属大气腐蚀规律的有效工具,目前还没有形成统一的规范和成熟的产品。为此,本文开发了5因素的复合模拟环境腐蚀试验装置,可精确调整、控制主要腐蚀影响因子和环境参数。试验结果表明,该系统具有较好的加速效果。本文采用野外大气环境和实验室模拟环境相结合的方法,开展了Zn/C电偶型ACM的长期、实时和原位的检测和热浸镀锌试样的腐蚀试验,研究了大气环境温度、湿度对锌腐蚀影响的规律；研究了环境中Cl-加速锌腐蚀作用机制和对锌腐蚀动力学影响的规律和特征；研究了环境中S02中间产物在锌腐蚀中的竞争作用和锌腐蚀动力学规律和特征。结论如下：锌在大气环境中的腐蚀速率受温度与湿度的联合作用影响。随温度和湿度的升高,锌的腐蚀速率都会增大,其中湿度对腐蚀速率的影响作用较温度明显。并且温度和湿度两者之中的任何一个的升高都会加大另一个对锌腐蚀速率的影响程度,即温度和湿度对锌腐蚀的影响存在耦合联动作用机制。依据锌在模拟环境中的腐蚀试验数据建立的温度、湿度对锌溶解耦合影响的二元二次数学模型,得到了野外环境检测数据的验证。与润湿时间(TOW)模型相比,耦合影响模型可更精确地反映大气环境中温度、湿度对锌腐蚀行为的影响规律。锌在不含侵蚀性离子大气环境中的腐蚀,经历了腐蚀初期阶段电极反应控制的活化溶解到混合控制直至扩散控制的演变过程。经长期腐蚀后的锌在无侵蚀性离子环境中的腐蚀动力学规律遵循幂函数模型。在含C1-的大气环境中,由于表面有盐的沉积,锌的腐蚀能够一直保持活化溶解状态。随腐蚀时间的延长,锌腐蚀产物不能形成有效阻挡层,因而锌在该环境中的腐蚀动力学呈线性规律特征。由于Cl-在锌表面的吸附,使双电层形成非线性电位区,降低了锌脱离基体的位能趋势,使得锌溶解活化能降低。随Cl-浓度增加,锌溶解速率增大。当Cl-吸附率达到极限值时,锌溶解速率最大,继续增大Cl-浓度,锌的溶解会受到阻碍,溶解速率反而降低。在含SO2的大气环境中,锌的腐蚀除受酸化作用外,还受SO2中间产物SO32-和SO42-等离子竞争作用影响。SO32-在锌表面形成难溶性亚硫酸盐,其进一步氧化为硫酸盐非常困难,对锌的溶解形成阻碍作用。SO42-对锌的溶解有加速作用,其加速机制与Cl-大致相同。当大气中SO2浓度低于10ppm时,四价硫转化为六价硫的比例较高,以SO42-的作用为主,锌溶解速率较大。SO2浓度增大,四价硫转化为六价硫比例降低,SO32-作用增强。当浓度达到10ppm时,SO32-在锌表面的吸附达到极值,锌溶解速率下降到谷值。SO2浓度继续升高,超过10ppm时,SO42-浓度增大,溶液酸性增强,亚硫酸盐溶解度增大,其阻挡作用削弱,使得锌溶解速率再次呈上升趋势。在一般含有SO2的大气环境中,由于SO2浓度远低于10ppm,四价硫氧化为六价硫趋势较强,故其对锌的腐蚀影响作用以SO42-的加速锌溶解机制为主,从而能使锌保持活化状态,使锌在该种大气环境中的腐蚀动力学遵循线性规律特征。
[Abstract]:Because of its low corrosion potential and corrosion rate, zinc has become an ideal material for corrosion protection of iron and steel. But in different regions, the anticorrosion effect of zinc coating varies widely and life span is different. However, the effectiveness and timeliness of this method are repeatedly criticized by the complexity of the atmospheric environment and the long period of corrosion failure. So far, the corrosion failure laws of the zinc coating in the natural atmosphere have not been fully understood. Price means, the amount of data obtained is little, it can not fully reflect the change process of atmospheric corrosion of zinc with time, which brings great difficulty to the study of atmospheric corrosion of zinc, and it is easy to produce large error. To carry out long-term, continuous, real time, in situ evaluation becomes the general trend of corrosion in the atmosphere. Therefore, this article is aimed at the atmospheric environment of zinc. Corrosion developed a new type of atmospheric corrosion tester (ACM). The ACM used inert carbon film as the cathode material, effectively eliminating the electrochemical performance changes caused by the synchronous corrosion of the cathode materials in the traditional ACM. The three layer superposition structure makes the cathode and anode materials in the two parallel planes, avoiding the anode corrosion products. The influence of the surface of the cathode material improves the consistency and service life of the sensor. The developed ACM detector adopts the dual power supply mode of the solid state battery and the solar panel, and uses the GPRS to realize the remote transmission of the data, which reduces the information loss and data error caused by the manual operation of the traditional exposed sample method, and ensures the zinc. The stability of corrosion data in real atmospheric environment. Through field environment, simulated environment and zinc surface modification, the results show that the ACM can meet the long-term, continuous, real-time and in-situ corrosion detection work. It is an effective means to study the corrosion of zinc in the atmosphere and master the atmospheric corrosion law of zinc. The multi factor cyclic compound experiment is a simulation. The important means of atmospheric corrosion and acceleration and reproducibility is an effective tool to study the corrosion law of metal atmosphere. At present, there is no unified standard and mature product yet. Therefore, this paper has developed a compound simulated environmental corrosion test device with 5 factors, which can be adjusted accurately and control the main corrosion factors and environmental parameters. The experimental results show that the system has good acceleration effect. In this paper, the long-term, real time, in situ and galvanized corrosion tests of Zn/C galvanic ACM are carried out by combining the field atmosphere environment with the laboratory simulation environment, and the influence of atmospheric temperature and humidity on zinc corrosion is studied. The mechanism of Cl- accelerated zinc corrosion and the regularity and characteristics of zinc corrosion kinetics in the environment. The competitive action of S02 intermediate products in the environment and the kinetics and characteristics of zinc corrosion were studied. The conclusions are as follows: the corrosion rate of zinc in the atmosphere is affected by the combination of temperature and humidity. The corrosion rate of zinc will increase, and the effect of humidity on the corrosion rate is more obvious. And the increase of any one of the temperature and humidity will increase the effect of another on the corrosion rate of zinc, that is, the coupling interaction mechanism between temperature and humidity affects the corrosion of zinc. The temperature of the corrosion test data in the environment and the two yuan two mathematical models of the influence of humidity on the coupling of zinc dissolve have been verified by the field test data. Compared with the wetting time (TOW) model, the coupling influence model can more accurately reflect the influence of temperature and humidity on the corrosion behavior of zinc in the atmosphere. The corrosion in the atmospheric environment has experienced the evolution process of the activation dissolution controlled by the electrode reaction in the initial stage of the corrosion to the mixed control and the diffusion control. The corrosion kinetics of zinc after long-term corrosion in the non erosive ion environment follows the power function model. In the atmospheric environment containing C1-, the surface has salt deposition, The corrosion of zinc can remain active and dissolved. With the prolongation of corrosion time, the zinc corrosion product can not form an effective barrier layer. Therefore, the corrosion kinetics of zinc in this environment is linear. The adsorption of Cl- on the zinc surface makes the double layer form a nonlinear potential area and reduces the potential trend of zinc detachment from the matrix, so that zinc is reduced. The dissolution activation energy is reduced. With the increase of Cl- concentration, the dissolution rate of zinc increases. When the Cl- adsorption rate reaches the limit value, the dissolution rate of zinc is the largest, and the Cl- concentration continues to increase. The dissolution of zinc will be hindered and the dissolution rate decreases. In the atmosphere containing SO2, the corrosion of zinc is also affected by the SO2 intermediate product SO32- and SO42- plasma. The competitive effect affects the formation of insoluble sulfite on the zinc surface, and its further oxidation to sulfate is very difficult. The dissolution of zinc has a hindering effect on the dissolution of zinc, and.SO42- accelerates the dissolution of zinc. The acceleration mechanism is roughly the same as that of Cl-. When the concentration of SO2 in the atmosphere is lower than 10ppm, the proportion of tetravalent sulfur to six is higher, SO42- The concentration of.SO2 is larger, the concentration of.SO2 is larger, the proportion of tetravalent sulfur is reduced to six, and the effect of SO32- is enhanced. When the concentration reaches 10ppm, the adsorption of SO32- on the zinc surface reaches the extreme value, the dissolution rate of zinc drops to the valley value and the.SO2 concentration continues to rise. When the concentration exceeds 10ppm, the concentration of SO42- increases, the solution acidity increases, and sulfite dissolves. As the degree of degree increases, the barrier effect is weakened, and the dissolution rate of zinc is on the rise again. In the atmospheric environment with SO2 generally, because the concentration of SO2 is far lower than that of 10ppm, the oxidation of tetravalent sulphur to six is stronger, so the effect of its corrosion to zinc is mainly based on the accelerated zinc dissolving machine of SO42-, thus making zinc active and zinc in its state. The corrosion kinetics in this atmosphere follows the linear rule.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG172
，
本文编号：2165100
[Abstract]:Because of its low corrosion potential and corrosion rate, zinc has become an ideal material for corrosion protection of iron and steel. But in different regions, the anticorrosion effect of zinc coating varies widely and life span is different. However, the effectiveness and timeliness of this method are repeatedly criticized by the complexity of the atmospheric environment and the long period of corrosion failure. So far, the corrosion failure laws of the zinc coating in the natural atmosphere have not been fully understood. Price means, the amount of data obtained is little, it can not fully reflect the change process of atmospheric corrosion of zinc with time, which brings great difficulty to the study of atmospheric corrosion of zinc, and it is easy to produce large error. To carry out long-term, continuous, real time, in situ evaluation becomes the general trend of corrosion in the atmosphere. Therefore, this article is aimed at the atmospheric environment of zinc. Corrosion developed a new type of atmospheric corrosion tester (ACM). The ACM used inert carbon film as the cathode material, effectively eliminating the electrochemical performance changes caused by the synchronous corrosion of the cathode materials in the traditional ACM. The three layer superposition structure makes the cathode and anode materials in the two parallel planes, avoiding the anode corrosion products. The influence of the surface of the cathode material improves the consistency and service life of the sensor. The developed ACM detector adopts the dual power supply mode of the solid state battery and the solar panel, and uses the GPRS to realize the remote transmission of the data, which reduces the information loss and data error caused by the manual operation of the traditional exposed sample method, and ensures the zinc. The stability of corrosion data in real atmospheric environment. Through field environment, simulated environment and zinc surface modification, the results show that the ACM can meet the long-term, continuous, real-time and in-situ corrosion detection work. It is an effective means to study the corrosion of zinc in the atmosphere and master the atmospheric corrosion law of zinc. The multi factor cyclic compound experiment is a simulation. The important means of atmospheric corrosion and acceleration and reproducibility is an effective tool to study the corrosion law of metal atmosphere. At present, there is no unified standard and mature product yet. Therefore, this paper has developed a compound simulated environmental corrosion test device with 5 factors, which can be adjusted accurately and control the main corrosion factors and environmental parameters. The experimental results show that the system has good acceleration effect. In this paper, the long-term, real time, in situ and galvanized corrosion tests of Zn/C galvanic ACM are carried out by combining the field atmosphere environment with the laboratory simulation environment, and the influence of atmospheric temperature and humidity on zinc corrosion is studied. The mechanism of Cl- accelerated zinc corrosion and the regularity and characteristics of zinc corrosion kinetics in the environment. The competitive action of S02 intermediate products in the environment and the kinetics and characteristics of zinc corrosion were studied. The conclusions are as follows: the corrosion rate of zinc in the atmosphere is affected by the combination of temperature and humidity. The corrosion rate of zinc will increase, and the effect of humidity on the corrosion rate is more obvious. And the increase of any one of the temperature and humidity will increase the effect of another on the corrosion rate of zinc, that is, the coupling interaction mechanism between temperature and humidity affects the corrosion of zinc. The temperature of the corrosion test data in the environment and the two yuan two mathematical models of the influence of humidity on the coupling of zinc dissolve have been verified by the field test data. Compared with the wetting time (TOW) model, the coupling influence model can more accurately reflect the influence of temperature and humidity on the corrosion behavior of zinc in the atmosphere. The corrosion in the atmospheric environment has experienced the evolution process of the activation dissolution controlled by the electrode reaction in the initial stage of the corrosion to the mixed control and the diffusion control. The corrosion kinetics of zinc after long-term corrosion in the non erosive ion environment follows the power function model. In the atmospheric environment containing C1-, the surface has salt deposition, The corrosion of zinc can remain active and dissolved. With the prolongation of corrosion time, the zinc corrosion product can not form an effective barrier layer. Therefore, the corrosion kinetics of zinc in this environment is linear. The adsorption of Cl- on the zinc surface makes the double layer form a nonlinear potential area and reduces the potential trend of zinc detachment from the matrix, so that zinc is reduced. The dissolution activation energy is reduced. With the increase of Cl- concentration, the dissolution rate of zinc increases. When the Cl- adsorption rate reaches the limit value, the dissolution rate of zinc is the largest, and the Cl- concentration continues to increase. The dissolution of zinc will be hindered and the dissolution rate decreases. In the atmosphere containing SO2, the corrosion of zinc is also affected by the SO2 intermediate product SO32- and SO42- plasma. The competitive effect affects the formation of insoluble sulfite on the zinc surface, and its further oxidation to sulfate is very difficult. The dissolution of zinc has a hindering effect on the dissolution of zinc, and.SO42- accelerates the dissolution of zinc. The acceleration mechanism is roughly the same as that of Cl-. When the concentration of SO2 in the atmosphere is lower than 10ppm, the proportion of tetravalent sulfur to six is higher, SO42- The concentration of.SO2 is larger, the concentration of.SO2 is larger, the proportion of tetravalent sulfur is reduced to six, and the effect of SO32- is enhanced. When the concentration reaches 10ppm, the adsorption of SO32- on the zinc surface reaches the extreme value, the dissolution rate of zinc drops to the valley value and the.SO2 concentration continues to rise. When the concentration exceeds 10ppm, the concentration of SO42- increases, the solution acidity increases, and sulfite dissolves. As the degree of degree increases, the barrier effect is weakened, and the dissolution rate of zinc is on the rise again. In the atmospheric environment with SO2 generally, because the concentration of SO2 is far lower than that of 10ppm, the oxidation of tetravalent sulphur to six is stronger, so the effect of its corrosion to zinc is mainly based on the accelerated zinc dissolving machine of SO42-, thus making zinc active and zinc in its state. The corrosion kinetics in this atmosphere follows the linear rule.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG172
，
本文编号：2165100
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