一、Summary

　　The coating process design of steel box girder is the most important part of the manufacturing process design of bridge steel structure. The coating process quality is not only related to the manufacturing quality of steel box girder and the service life of bridge, but also closely related to the cost reduction of steel structure and the improvement of economic benefits.

　　The painting design of steel box girder includes the technical requirements of surface treatment and painting, the formulation of correct technological process and measures, and the determination of various methods of painting management.

　　At present, the coating process design is based on the coating matching and technical requirements for the outer side of Xiazhang sea crossing bridge steel box girder, the construction performance of COSCO Guanxi matching coating, and the coating equipment and process line of Changxing base of Shanghai Zhenhua Heavy Industry Group Co., Ltd.

二、Coating process design basis

　　The coating matching scheme for the outer side of steel beam specified by the design institute is shown in Table 1.

　　Analysis of the above supporting schemes shows the following excellent performances:

　　1. Excellent corrosion resistance;

　　2. Excellent environmental protection performance;

　　3. The construction performance of the matching coating is excellent.

三、Design of coating process flow for outer side of steel box girder

　　It is the key to ensure the quality of coating to construct according to the correct coating process. In recent years, due to some coating engineering teams changing the process flow without authorization and cutting corners, there have been many coating quality accidents with profound lessons. According to the above three principles, the design process is shown in Figure 2-3.

　　This information is reproduced in "anticorrosive coating and coating" collected by Mr. Li Minfeng