| The deterioration and destruction of Metal materials caused by the chemical or electrochemical reaction with their service environment is known as corrosion. Corrosion is an extremely serious factor to the economic construction and people’s life, which brought huge economic losses and harm to the human and society. At present, the main methods to prevent metal corrosion include:choosing the corrosion-resistant material; controlling the corrosive environment (inhibitor); electrochemical protection; protective surface coatings and rational design of corrosion prevention. Among them, the surface coating and inhibitor are considered to be one of the most efficient, economical and popular way.During the exploration of oil and gas resource, acidizing is commonly used in stimulation in oil and water well which may corroded the ground tube and wellhole seriously as well. Thus, the inhibitor must be added into the acid to prevent the concurrent corrosion. However, improper using of inhibitor may cause the surface pitting, hydrogen embrittlement and weightloss of the construction equipment, oil and gas well tubing and downhole metal tools, and sometimes may result in burst accident of downhole pipes, causing severe economic loss. Consequently, the research and development of corrosion inhibitor for high temperature and high concentration of acid is the key to solve the corrosion problem, to ensure the smooth conduction for acidification of deep oil wells.A strong candidate of soft magnetic materials in many MEMS applications is the CoNiFe soft magnetic film due to its capable of providing an extremely high Bs combined with reasonably low He. Right now, the electroplating method is one of the most promising technologies to prepare the CoNiFe soft magnetic film because of its ability to "tailor" deposit structure and properties and to form a high-aspect-ratio film. However, the relationship between the deposition overpotential and the film growth rate has not been reported. This paper was divided into two parts, one of the works on the protective films was supported by the project (GY-KY2009-16) from Sinopec Tahe oil field, and the other one on the magnetic films was supported by the National Natural Science Foundation of Chian (No.50741005). The concent of this paper mainly includes:evaluation of corrosion prevention effect of coatings used in oil-gas field; preparation and characterization of a new imidazoline inhibitor based on linseed oil and study on its inhibition mechanism on Q235electrode; characterization and inhibition behavior of benzotriazole on copper electrode and setting up and verifying a new model between the electrodeposition potential bias and growth rate of CoNiFe soft megnatic film.Firstly, the paper deals with the evaluation of corrosion prevention effect of coatings used in oil-gas field and establishs a systemic means to obtain the unticorrosive coatings,(a) firstly, the unit area and unit thickness of coating resistance and capacitance was taken to be evaluation index of unticorrosion properties, and the unit area and unit thickness of coating resistance was the priority; then the protective efficiency and porosity was used to determine their protective properties at their service period,(b) Electrochemical methods were used to evaluate the corrosion prevention property, thermogravi metric method was used to evaluate the thermostability, and the adhesion, wear resistance and hardness was compared. Results reveal that the coating "PH52-2elastic network conducting electrostatic anticorrosion coating primer+PH52-2elastic network conducting electrostatic anticorrosion topcoat" has the best protective properties; Economic type "1106-4zinc-rich epoxy primer+1152-1micaceous iron oxide epoxy paint+BS52-2polyurethane topcoat" is practicable. Meanwhile, the structure of "PH52-2elastic network conducting electrostatic anticorrosion coating primer+PH52-2elastic network conducting electrostatic anticorrosion topcoat" was analysed:new C-N bond was generated after the modification of epoxy coatings with polyurethane, which has excellent chemical resistance due to its high bond energy, and after consolidation, these two different kinds of networks run through each other to form a uniform at a macro and micro phase separation of blends, simultaneously as a result of the hydrogen bond function. This blend system conbines both the advantages of polyurethane and epoxy resin, which greatly enhance the flexibility, the intensity, the adhesion and penetration resistance.Secondly, a new imidazoline inhibitor based on linseed oil was synthesized. The inhibition efficiency of this inhibitor has been tested through weight loss method, and the inhibition effect was compared with other inhibitor commonly used in the oil field, results indicate that the synthesized linseed oil inhibitor has high inhibition efficiency with smaller amount. Tafel and electrochemical impedance technique were used to study the inhibition behavior of linseed oil based imidazoline inhibitor on Q235steel.Results obtained from Tafel test agree well with the EIS measurements, the inhibition efficiency increases with increasing the concentration of inhibitor, the adsorption behavior of linseed oil imidazoline inhibitor on Q235steel follows Langmuir adsorption, and it is chemisorptions.Additionally, the adsorption behavior of benzotriazole on copper electrode was also studied. Three models were established to analyze the adsorption dynamics at different conditions. Adsorption of BTAH followed Langmuir adsorption isotherm when adsorption-desorption reached steady-state. BTAH film growth can be best represented by exponential decay law assuming the concentration of BTAH in the solution was constant over time. Higher-order model was established to evaluate adsorption dynamics considering the variation of BTAH concentration in the bulk solution. The adsorption rate constant and desorption rate constant were different while different modles were used to analyze the adsorption process.At last, the electrodepostion behavior of CoNiFe soft magnetic film on brass substrate was studied mainly by electrochemical impedance which was supported by National Natural Science Foundation of Chian (No.50741005). Functional relationships between deposition rate and cathodic potential bias was established theotically for the first time that the charge transfer resistance of the deposition process decreases exponentially with the applied potential bias. |
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