Galvanized metal electrical conduit pipes are widely used in construction and industrial applications due to their durability and corrosion resistance. Among various galvanizing processes, galvanizing stands out for its efficiency and speed. In this blog, we explore the process characteristics of sulfate galvanizing and how it has been optimized for enhanced performance.
Galvanizing is renowned for its 100% current efficiency and exceptionally fast deposition rate, making it one of the most efficient galvanizing processes. However, traditional sulfate galvanizing has some limitations, such as poor dispersion ability and deep plating capacity, which restrict its use to simple geometric shapes like pipes and wires.
To address these challenges, the process has been optimized by introducing a zinc-iron alloy coating. This innovation involves retaining only the main salt, zinc sulfate, while eliminating other components from the traditional formula. An appropriate amount of iron salt is added to create a zinc-iron alloy coating. This new approach retains the high current efficiency and fast deposition rate of the original process while significantly improving dispersion and deep plating capabilities.
The optimized galvanizing process not only enables the electroplating of both simple and complex parts but also enhances the protective performance of the coating. Tests show that the corrosion resistance of the zinc-iron alloy coating is 3 to 5 times higher than that of a single metal coating.
For continuous electroplating of wires and pipes, this process produces coatings with finer grains and brighter finishes. Remarkably, the required coating thickness can be achieved within just 2 to 3 minutes, a significant improvement over traditional methods.
During the conversion to the zinc-iron alloy process, only zinc sulfate is retained as the main salt, while other components like aluminum sulfate and alum are removed from the plating solution. These components can form insoluble hydroxide precipitates, which are eliminated by adding powdered activated carbon.
Although complete removal of substances like aluminum sulfate and potassium aluminum sulfate may be challenging, their impact on coating brightness is minimal and can be mitigated over time. Regular replenishment of component content ensures a smooth transition to the new process.
The sulfate galvanizing process for zinc-iron alloys boasts an unparalleled deposition rate, with fine tubes running at speeds of 8-12 meters per minute. The average coating thickness is 2 micrometers per minute, a feat difficult to achieve with other continuous galvanizing methods.
The resulting coating is bright, delicate, and highly durable. According to the national standard GB/T10125 for salt spray testing, the coating remains intact and unchanged for 72 hours. Even after 96 hours, only a minimal amount of white rust appears on the surface, demonstrating its exceptional corrosion resistance.
The optimization of sulfate galvanizing for zinc-iron alloys represents a significant leap forward in the production of galvanized metal electrical conduit pipes. This process combines speed, efficiency, and enhanced protective performance, making it ideal for a wide range of applications.
