HC Surface Treatment Network: Abstract: For a long time, due to the acid rain atmosphere in the severe high temperature climate in Chongqing, the metal structural parts of the track beam, especially the easily rusty Q235 ordinary steel finger plate components, have been seriously rusted during the operation of the track line. , Has jeopardized the unblocked rail line and the safety of train operation. This article introduces the use of zinc-nickel coating to achieve feasible and reliable heavy-duty anti-corrosion protection for the PC beam finger plates of Chongqing light rail, which provides an intentional reference for designers of public transportation facilities.
Keywords: heavy-duty anti-corrosion, rail transit, PC beam finger plate
Chongqing Track Beam Bridge System Research Center Zhang Yanzhen
Chongqing Dayou Surface Technology Co., Ltd. Ren Youqian Zhang Guansun
Chongqing Coating Industry Association Long Zhongjun
1. Starting from the current situation of Chongqing's atmospheric environment
The typical acid rain characteristics in Chongqing, coupled with high temperature, high humidity and man-made pollution emissions, have resulted in a very harsh air environment in Chongqing. In terms of acid rain in Chongqing, atmospheric monitoring from 1987 to 1989 found that the average pH of rainfall in the main urban area of Chongqing was around 4.0, of which it reached more than 3 points in one winter, which is similar to edible "vinegar". Among them, SO42- actually accounts for about 80% of the total anion, which is a typical sulfuric acid type acid rain. A set of data published in the 2002 Chongqing Environmental Quality Briefing: The average pH of acid rain in the main urban area of Chongqing is 4.67; the average pH of acid rain in 22 districts and towns in the "acid control zone" is 4.73. As far as the high temperature in Chongqing is concerned, according to statistics, although the annual average temperature in Chongqing is 18℃, the annual temperature fluctuates between 1℃ and 46℃, and the number of days between 30℃ and 45℃ can reach about 100 days. According to inspections, the relative humidity of Chongqing's atmosphere is 80.7%, and the annual relative humidity is greater than 80% for 213 days. By 2009, the overall environmental quality has improved greatly. The concentration of SO2 and NO2 in the ambient air of the main urban area has dropped significantly compared with previous years, and the acidity of precipitation has weakened. However, efforts are still required in accordance with the requirements of Chongqing's "clear air project".
In such a harsh acid rain environment, the Chongqing No. 1 rail line has only been in operation for a few years, and the PC beam finger plate components of the rail have been severely rusted, which has endangered the smooth flow of the rail line and the safety of train operation, and has also attracted the attention of the transportation department. From the beginning of the first line of the young rail in 2004, the Chongqing transportation department and related units have done a lot of work on the PC track beam finger plate, which is a key part of the light rail with prominent corrosion problems. After investigating various heavy anti-corrosion systems, Multi-variety spot test, complete set of verification, running on track, etc., screened out feasible zinc-nickel coating technology, solved the problem of heavy anti-corrosion of PC track beam finger plate, and basically contained this endangering the smooth flow of track and train An invisible killer that runs safe.