Preparation And Properties Of The Mechanism For Coating Heat Exchanger Components

The increasing demands for the life of equipments is produced in the area of rapid developping petrochemicals recently. The direct economy loss caused by corrosion amounts to 0.2 billion RMB. The indirect economy loss caused by corrosion can not be imagined. This shows the importance of corrosion. Disposing the surface on carbon steel through proper measure is one of the ways to solve the problem of equipments corrosion in the area of petrochemicals. The electroless technology ,which is charactered by anti-corrosion, provides with an advanced method for this. This project is attended to do as this follows: applying electroless technology to the environment mentioned above; designing a new electroless prescription; studying the character of coating produced by electroless technology related; searching for a new type of sealing technique; investigating the corrosion behavior and mechanism of electroless Ni-P alloy.The key to the electroless technology; which is crucial to achieve an excellent coating and decrease the price; is to design the new electroless prescription, the characteristics of the coating and life. Through orthogonal objected to deposit velocity and P content, the optimized prescription is got on the basis of experiments. The experiment results show that the coating with low porosity and excellent anti-corrosion can be achieved using the electroless prescription.With regard to the characteristics of the coating, this project mainly deals with the following task: the element content of the coating is measured by using XRD; the thickness of the coating is measured by using OM, thus gets the average velocity of deposit; the microstructure is tested by using EPMA;then ; The form mechanism and process of electroless Ni-P alloy is analysed. The HV is tested by using Sclerometer; the porosity is tested by using corrosion; the average velocity of corrosion is tested by using soakage. In the end, two kinds of sealing procedure for the Ni-P alloy coating have been developed. It was confirmed that the corrosion resistance of Ni-P alloy coatings after sealing was increased by comparing the porosity and observation of EPMA before and after sealing.Through the surface disposing, the carbon steel can substitute the stainless steel in the environment of corrosion. This subject develops a kind of surface coating technology. This not only reduces the price but also increases the life of the equipments. As a result, economical and efficient application of the material comes true.