TIG welding is a process that uses an electrical arc of current to heat a part, to melt and fuse two separate pieces of metal together quickly and effectively, and is the most commonly used welding for crucial applications such as those seen in the automotive, aerospace, and medical industries. However, as with any welding process, TIG welding comes with its own set of flaws- commonly in the form of crakes, lack of fusion, excessive and insufficient weld bead thickness, undercuts, and porosity, to name just a few. Recognizing and addressing these issues is essential to obtaining a quality weld.
One common issue associated with TIG welding is a lack of fusion. This occurs when insufficient heat is applied to melt and fuse the two pieces of metal together, resulting in a lackluster and potentially even dangerous weld. To prevent a lack of fusion, welders should ensure the appropriate amperage, heat, travel speed, and filler material are all used, as these factors all attribute to the strength and quality of the weld. Additionally, a properly adjusted gas cup and clearly marked weld joint edges beforehand can also help reduce the instances of lack of fusion.
TIG welding is often prone to the creation of porosity, or a variety of small, irregularly shaped (and usually circular) holes that occur during the welding process when air is trapped inside the weld. These cavities can be detrimental to the strength and durability of the weld and should therefore be avoided whenever possible. To reduce the occurrence of porosity, welders should always use properly prepared and clean weld joints to start with and reduce any chances of contaminants such as oil, dust, or rust seeping into the weld. Additionally, adhering to the correct parameters by using the right filler material, amperage, and plasma arc length is paramount in eliminating the chances of porosity occurring.
It is also possible for TIG welds to suffer from insufficient weld bead thickness. This is when either too little base metal is available, or too little filler material is added, to maximize the overall weld bead thickness. Insufficient weld bead thickness can significantly weaken a weld and render it unusable for its intended purpose. To combat this, welders should always check that there is enough base metal available before starting a weld and match the size of the welding rod or filler material to the thickness of the metal that is being joined. As welders may encounter both thin and thick sheets of metal, it is important to understand which parameters to use for each type.
Lastly, cracks are a common issue with TIG welds, caused predominantly by a weld cooling too quickly as a result of insufficient heat being applied. Cracks can result in a weakened and potentially hazardous weld and should always be critically examined throughout the welding process. To prevent cracks from occurring, welders should ensure they use the correct amperage and heat when welding and not be tempted to rush the weld to save time.
In conclusion, TIG welding is a highly efficient process used to fuse metal parts together quickly and effectively. However, it is prone to various issues such as lack of fusion, porosity, weld bead thickness, and cracks. To address these issues, welders must adhere to the correct parameters for each weld and pay careful attention to the cooling process, making any necessary adjustments when needed. In doing so, welders can prevent these issues from occurring and produce a weld of the highest quality.
