Bundling bars and its Causes and Treatments
Bundling bars, sometimes known as bar marks or bar spots, are dark spots visible on bars of steel, aluminium and other metals. While bundling bars may raise concerns about the quality of metals, this form of discolouration is often harmless and does not affect the performance of the metal itself. It is possible to reduce or completely eliminate the chance of Bundling bars by changing various factors related to the manufacturing process.
In order to better understand how to reduce the prevalence of Bundling bars, it is important to understand what causes them in the first place. Generally, Bundling bars are formed when two pieces of metal are joined together and a galvanic reaction occurs. This occurs when two different metals (or different parts of the same metal) are in contact with one another, resulting in a difference in electric potential between the two pieces. This difference can cause a reaction which results in the formation of Bundling bars.
The most common cause of Bundling bars is an uneven or unequal surface finish on the two parts. This can cause a difference in electric potential due to the varying degrees of roughness or smoothness on the two pieces of metal. Inadequate cleaning can also increase the likelihood of Bundling bars due to the presence of dirt and oils, which can act as insulators, hindering the electric flow between the pieces.
The best way to reduce the chance of Bundling bars is to ensure the surfaces of both pieces are clean and have the same degree of finish. This can be done by cleaning the pieces with an appropriate degreasing agent before assembly, and then giving them a uniform finish with appropriate abrasives.
In some cases, bundling bars can also be avoided by using antiseize compounds. These compounds contain chemical components known to prevent the formation of chemical reactions between the two pieces. It is important to note that antiseize compounds should not be used on food grade or pharmaceuticals products.
Preventing the formation of Bundling bars is important, as these spots can significantly reduce the durability of a metal and make it more prone to corrosion and rust. This is because the chemical reaction which causes Bundling bars generates heat, creating tiny pits in the surface of the metal. These pits are prime locations for rust and corrosion to form.
While it is possible to reduce the prevalence of Bundling bars with proper cleaning, it is important to note that this will not completely eliminate the chance of this issue occurring. Bundling bars can still form even if all manufacturing processes are completed correctly, so if this issue does occur it is important to take appropriate action. In many cases, the metal can be sanded or grinded to remove the Bundling bars, restoring the metal’s original properties. In severe cases, the metal may need to be replaced entirely.
In conclusion, Bundling bars can be an issue encountered during the manufacture of steel bars and other metals. However, the occurrence of Bundling bars can be minimised by taking proper precautions, such as ensuring the surface finish on both pieces is even and providing thorough cleaning. In cases where Bundling bars do form, appropriate action can be taken to remove the issue and restore the metal’s original properties.
