Research On The Tech Nology Of Plasma Spraying Corrosion Resistance Coating

The corrosion of metallic material is a problem which can not be ignored in material science and engineering nowadays. Using thermal spraying technology to achieve corrosion prevention is one of the most competitive ways. The thermal spraying technology is an important method for surface coating preparation and also a central branch of surface engineering, which contains technology, materials, equipment, testing, etc. Corrosion resistance is a crucial function of the coating.Aiming at the life of the Liquid Density Test Online which used in chemical plants under the corrosion in liquid of detection process, a reasonable corrosion resistance coating was designed and the corresponding optimal spray technology was formulated. The plasma spraying technology was used to produce coating. Besides, the performance index and corrosion resistance of the coating were detected. Ordinary carbon steel Q235 was chosen as a matrix for the sample, the Ni/Al and Ni/Cr 80/20 were respectively used as the bottom and the work layer. And the E-44 epoxy resin and 650 polyamide of low molecule weight which were mixed in 1:1 ratio and diluted with moderate acetone were used for sealing in the obtained coating. And the performance index of the Ni/Cr 80/20 coating was detected, including thickness, hardness, bonding strength, deposition efficiency, porosity and metallographic analysis. Overall, the good performance of the coating shows the achievement in the most suitable technology and the best protective effect of the coating. Through the Total Immersion Experiment within 500h in the four typical corrosive media, the corrosion behavior of the coated sample was studied. The corrosion results were analyzed by using macroscopic observation of the surface, evaluation of weight and microscopic analysis of scanning electron microscopy. The results show that Ni/Cr coating plays a bad corrosion resistance in HCl. However, it could meet the needs of liquid density tester online in other environment.In this paper, a rational corrosion resistant coating was designed and the optimal process parameters was obtained, which can provide theoretical basis and guidance for equipment protection in practical production.