Chongqing Dayou Surface Technology Co., Ltd. is a scientific and technological enterprise established to develop and introduce internationally advanced metal and non-metal surface treatment technologies. It has self-developed zinc-nickel infiltration layer and imported chemical autophoretic metal anticorrosion technology, and has annual processing Capacity of tens of thousands of tons.

 

　　The "Zinc-Nickel Infiltrated Metal Anti-corrosion Technology" independently developed by the company has become Chongqing Light Rail because of its unique high anti-corrosion, high hardness, high wear resistance and its advantages in energy saving, environmental protection, zinc saving, and low cost. Major national projects such as Guangzhou, Shenzhen, Chongqing, Chengdu Metro, Guangzhou-Wuhan High-speed Railway, and Yusui double-track railway have been adopted in batches. At the Fifth Urban Rail Transit Sustainable Development Forum held in Beijing in 2009, it attracted the attention of relevant experts and was hailed as a major breakthrough in anti-corrosion technology for rail transit metal components. It is recommended to promote it nationwide.

The metal components of urban rail transit are exposed to the wild for many years. They are not only exposed to the sun and rain, but also corroded by urban acid rain, acid fog or ocean salt spray. The humid underground environment of the subway also poses a huge impact on the subway metal components and its auxiliary equipment. The threat of corrosion, how to effectively prevent the corrosion of metal components for a long time, has always been one of the difficult problems surrounding the sustainable development of urban rail transit.

 

　　Chongqing Dayou Surface Technology Co., Ltd. cooperated with the Track Beam Bridge Research Center of Chongqing Rail Transit Corporation to develop a new heavy-duty anti-corrosion surface treatment technology especially suitable for rail transit metal components-"Zinc-Ni Infiltration Layer Anti-corrosion Technology". This technology has no three wastes discharge and is resistant to acid rain corrosion. The salt spray test can reach more than 600 hours, and the sulfur dioxide test can reach more than 168 hours, which can ensure that the metal components will not rust for 20 years; wear resistance and impact resistance, and the surface hardness can reach 300-400HV.

 

　　The technology has been successfully applied to the anti-corrosion renovation project of the finger plate system of the zoo section of Chongqing Light Rail Line 2. After 26 months of testing, no rust spots have appeared. Chongqing Rail Transit Corporation has fully adopted the finger plate system of Chongqing Light Rail Line 3 and the track fasteners of Metro Line 1 to solve the anti-corrosion problem of metal components in urban rail transit.