Galvanized steel welding is a process in which the welder operator fuses two pieces of steel together that have undergone the galvanization process in order to prevent oxidization. Galvanized steel welding is often considered to be one of the most dangerous types of welding because of the fumes generated from the excessive heat applied to the galvanized layer of steel during the welding process. The danger associated with galvanized steel welding often requires the welder operator to be more experienced than an ordinary MIG or TIG welder, even though the basics of the welding process are basically the same.
The process of welding two pieces of steel together happens at an extremely high temperature. The heat generated by an arc in the welding process often needs to exceed 15,000 degrees Fahrenheit (8,315 degrees Celsius) in order to be hot enough to melt steel, which has a melting temperature of just over 2,400 degrees F (1,315 degrees C). The problem encountered when welding a piece of galvanized steel is that the temperature at which zinc becomes vaporized is under 1,000 degrees F (537 degrees C), meaning that by the time the welding temperature has been reached, the zinc coating at the point of the weld has completely been vaporized from the piece being welded.
As a result of the vaporizing zinc problem, there are some methods of galvanized steel welding that include waiting to galvanize the pieces until after the weld has taken shape. This means the galvanization process is be applied after the weld has taken place so there is less danger in welding. This method, however, requires protecting the weld during the galvanization.
Due to time constraints and the need for efficiency in many manufacturing environments, however, this process of welding then galvanizing has not been used as much as conventional galvanized steel welding methods involving steel. Though the danger is still present when welding a piece of steel that has been galvanized, it is still often a necessary choice because of the fact that many fabrication facilities do not possess the necessary equipment for galvanizing the material after welding.
Galvanized steel has been used in thousands of different applications since it was realized that coating steel in zinc created a material that would resist rusting. It’s even been used to create rust-resistant cables for suspension bridges, which are exposed to the elements possibly more than in any other application. Due to the increased use of galvanized steel, many items that have been galvanized also need to be welded together to create parts for use in outdoor applications, and galvanized steel welding has likewise become more common.