When it comes to the TIG Welding polarity, it has a straight polarity, which is also called the DC electrode negative (DCEN). This welding process is using a negative torch that has positive work. In this, most heat is concentrated at the base metal (and not at the electrode), which is what we want.
Polarity refers to the direction of the electrical current that flows through the welding circuit.
For DC TIG welding of steel, stainless steel, etc., the TIG torch is connected to the negative (-) terminal, and the earth lead is connected to the positive (+) terminal. This is known as DC- polarity. The flow of current from the negative (-) to the positive (+) terminal creates a welding arc that is stable and consistent, making it ideal for welding these types of materials.
For AC TIG welding of aluminum, the polarity is usually the opposite of DC polarity. The TIG torch is connected to the positive (+) terminal and the earth lead is connected to the negative (-) terminal. This type of polarity is used because aluminum is a reactive metal that requires the use of AC current to create a clean and consistent welding arc.
There are two main types of polarity used in TIG welding: direct current electrode negative (DCEN) and direct current electrode positive (DCEP).
Direct current electrode negative (DCEN) polarity, the electrode is negatively charged and the workpiece is positively charged. This polarity is often used for welding thin materials and provides a stable arc that is easy to control. With DCEN polarity, the electrode heats up faster and the heat is concentrated at the tip of the electrode, which reduces the chances of contaminating the weld.
Direct current electrode positive (DCEP) polarity is where the electrode is positively charged and the workpiece is negatively charged. This polarity is typically used for welding thicker materials and provides a hotter, more penetrating arc that is better suited for welding thicker materials. However, with DCEP polarity, the heat is distributed evenly along the length of the electrode, which can increase the chances of contaminating the weld with tungsten inclusions.
The polarity used in TIG welding can have a significant impact on the quality of the weld. It is important to select the correct polarity for each welding application to ensure the best results. Whether you’re welding thin or thick materials, using the correct polarity can make a big difference in the outcome of your TIG welding projects.
