Research On The Structure And Anti-corrosion Performance Of Anti-corrosion Special Brass Alloy

In recent years,with the wide application of CO2 flooding technology,the production efficiency of oil and gas fields has been greatly improved,but it also brings serious security threats and economic losses.Therefore,it is particularly important to study the new anti-corrosion technology.In view of the unique properties of copper-zinc alloy,such as non-magnetic and non-electricity,it is also used as a new type of water treatment material in oil fields,but the scale is relatively small.There are also few experimental studies on related aspects.Therefore,research and preparation of a new type of copper-zinc alloy material with anti-corrosion function is of great significance for improving production efficiency and production safety in oil field environment.Based on the research results of corrosion mechanism and corrosion behavior of N80 steel in the produced water environment of the oilfield,this paper designs the experimental scheme based on the latest research results at home and abroad,and characterization of the special brass alloy structure to reveal its anticorrosion performance.The electrochemical properties of alloy materials are used to discuss the anti-corrosion mechanism,which provides theoretical basis and experimental demonstration for improving the safety of CO2 flooding technology for new anti-corrosion alloy materials used in oil fields.In this paper,the corrosion mechanism and the anti-corrosion mechanism of copper-zinc alloy materials are discussed.It is believed that copper-zinc alloy can reduce the corrosion of steel by CO2 and H2S by reducing Fe ionization and increasing the pH value of the solution.Secondly,after optimizing the alloy composition,a special brass alloy consisting of Cu,Zn,Ni and Sn is mainly prepared by adding a small amount of Mg,Al,Mn and rare earth elements.After obtaining a special shaped brass alloy,the microstructure was first characterized,and then its electrochemical behavior was studied.Finally,the corrosion resistance of the special brass alloy was studied in a saturated CO2 solution of 3.5 wt%NaCl.The results of structural characterization of special brass alloys show that after annealing at 600℃,the free surface energy of special brass alloy is the largest,the free energy is increased by 25.1%,and the polar component is increased by 42.74%.At this time,it is most beneficial to special brass alloys.The interaction of each ion in the solution;the alpha brass phase is the main constituent phase of the special brass alloy,and the preferred orientation crystal plane of the a brass phase crystal changes after heat treatment,and the presence of the second phase content enhances the corrosion resistance of the special brass alloy.The metallographic structure of the special brass alloy is mainly composed of equiaxed crystals.After heat treatment,the composition is more uniform,which is more favorable for the reaction of the primary battery on the surface of the alloy.The electrochemical properties of special brass alloys show that the crystal structure of the a-brass phase crystal structure(200)in the special brass alloy has strong electron-releasing ability.The phase analysis results show that the a-brass in the as-cast special brass alloy can be found.The phase crystal growth mode is preferentially grown by the(111)crystal plane.After heat treatment,the special brass alloy a brass phase crystal becomes the(200)crystal plane preferred orientation.In the saturated CO2 solution of 3.5 wt%NaCl,the as-cast special yellow The corrosion potential of copper alloy is the highest,the corrosion current density is the smallest,the surface charge transfer resistance is the largest,the electrochemical corrosion tendency of special brass alloy is enhanced after annealing,and the electron-releasing ability is enhanced.The special brass alloy which is annealed at 600 ℃has strong electron-releasing ability and combines.The foregoing experimental results preliminarily concluded that the 600℃ annealed special brass alloy is more practical for anti-corrosion engineering applications.The corrosion resistance of special brass alloys shows that N80 steel has the highest corrosion rate in untreated medium,the most severe corrosion,and the corrosion rate increases with the increase of temperature,the more serious the corrosion degree,and the corrosive medium after special brass alloy treatment.In the middle,the corrosion rate and corrosion degree of N80 are significantly reduced.The surface corrosion product film covers denser self-corrosion potential and charge transfer resistance,and the surface activity is also reduced,indicating that the corrosion degree of N80 steel is reduced and corrosion.The tendency is weakened.It is confirmed that the special brass alloy has a certain anti-corrosion effect,and the anti-corrosion effect of the special brass alloy annealed at 600℃ is better.