It also has the same elasticity as steel. Aside from that, it has the corrosion-resistant features of the zinc-iron coating. Furthermore, galvanized steel is mostly used for modern steel frame buildings. Some industries that utilise galvanized steel include wind and solar industries, automotive industries, construction industries and telecommunication industries.
There are certain issues that welders might encounter when welding galvanized steel. Here are some of them. Corrosion resistance is a common problem when it comes to welding galvanized steel. The idea of galvanizing is to prevent the steel from rusting. However, you need to get rid first of the galvanizing zinc across the welding area, thus, uncovering the area for corrosion. The only way to work this out is to galvanize the steel again after the welding is completed. Although it is time-consuming, it is a practical method to maintain the corrosion-resistant property of the material.
Apart from the health issues that welding galvanized steel can pose, there are other problems that you may encounter.
One of the challenges when it comes to welding galvanized steel is that the zinc coating found on galvanized steels. This material can compromise the weld. Since there is a coating, it makes the penetration more difficult. Moreover, it can cause a weld to have inclusions and porosity. To weld galvanized steel successfully, a skilled welder is required.
Furthermore, to solve the coating issue, the zinc coating should be removed from the area where you are welding. A filler material can also be used on the zinc-coated portion of the welding area. To avoid or minimise the issues when it comes to galvanizing steel, it is crucial to have general care and maintenance of your products. Here are some important guidelines to do this. Other than the material issues, there are also health risks that operators may encounter. To learn more about these hazards, read more below.
When welding galvanized steel, the zinc coating easily vaporises. This will form zinc oxide fumes that will mix with the air. Welders may experience flu-like symptoms once they inhale the fumes. These may include nausea, headaches, high fever, shivers and thirst.
The symptoms will usually go away within 48 hours of exposure. There is a small lead content on the galvanized coating. When welding, this lead will vaporise and form lead oxide fumes. These gases can cause long-term health problems such as lung and brain cancer and even complications in the nervous system.
Thus, it is crucial to wear the proper safety equipment to avoid these health problems. From the safety concerns mentioned above, it all boils down to the lack of welder safety training. It is vital that the welder is well-trained. The welder should also be in a proper position so that the clean airflow is maximised.
For safety purposes, the welder should be provided with a high-quality mask. They should also be fully trained on the safety measures when in terms of welding.
To make sure that the operator is safe while welding, it is essential to follow these tips. Below are some safety welding practices. When the galvanized steel is hot-dipped the zinc has a chemical reaction with the base metal and forms a corrosion resistant coating. This results in the outer layer of the metal have a coating of pure zinc while subsequent layers change in composition until you reach the iron base metal. In the outer layer and iron base metal, zinc oxide can be found in different percentages of zinc to iron.
The zinc oxide that is found on galvanized steel shares the same chemical attributes as the white powder that is used by lifeguards to protect their noses from becoming sunburned. Whenever you are working with galvanized steel it is important that you take the necessary steps when prepping the metal before welding. If you have properly prepped your metal before welding, you will help reduce your exposure to zinc oxide fumes.
While prepping the base metal will remove the majority of the zinc from the surface of the metal, the possibility of some galvanizing while welding may occur. A common sign of galvanizing is the appearance of yellowish-green smoke. Other signs are a white powdery particles in the air, and a white residue around the weld.
If exposure to large quantities of the yellowish-green zinc oxide fumes occur, you may experience galvanize poisoning, or metal fume fever as it is sometimes called. The severity of your symptoms depends on the amount of time of exposure to the harmful fumes. Symptoms of galvanize poisoning can be similar to flu symptoms. The onset of symptoms typically begin shortly after exposure to zinc oxide and may include a mild headache and nausea. If you have a more severe case of exposure, your symptoms will be consistent to those you experience when you have the flu.
It is also wise to weld in a well ventilated area, even when using a respirator. Welding galvanized steel can pose problems other than just health risks. The zinc coating found on galvanized steels can compromise the weld. The coating makes penetration more difficult and can cause a weld to have inclusions and porosity.
Lack of fusion at the toes of the weld is also common. Proper welding technique and processes must be used to mitigate these risks. If at all possible, remove the zinc coating around the weld area prior to welding. Otherwise, select a filler material that is made to be used on zinc coated materials. Another factor that will help to make quality welds is the type of galvanizing process that was used to coat the steel. Different types of galvanizing methods will leave different thicknesses of zinc on the steel surface.
Hot dipped galvanized steel and zinc thermal sprayed steel will typically have a thicker coating than zinc electroplated steel. Selecting a zinc electroplated steel can result in a better weld than thicker-coated hot dipped or zinc thermal sprayed steel.
Zinc electroplated steel will also have a far more uniform coating which is important when welding automation is being considered. Another hurdle when welding galvanized steel is maintaining corrosion resistance after welding. When galvanized steel is welded, the zinc coating at and around the weld burns away, leaving the area uncoated and unprotected.
0コメント