Which welding technique often employs the use of DC positive polarity?

In the context of welding techniques, MIG welding, or Metal Inert Gas welding, is known to often use direct current (DC) with positive polarity. When using DC positive polarity in MIG welding, the workpiece becomes the anode (positive terminal), and the electrode serves as the cathode (negative terminal). This arrangement is particularly beneficial for creating a stable arc and providing good heat input, which enhances penetration and fusion.

The positive polarity helps in producing a smoother weld pool and contributes to better arc stability, making it easier to manipulate the welding process. This characteristic of MIG welding is advantageous when working with various materials, especially aluminum and other non-ferrous metals, where a smoother arc can lead to quality outcomes.

In contrast, other techniques listed, such as shielded metal arc welding, submerged arc welding, and TIG welding, may use either AC or different polarities of DC depending on the specific requirements of the welding operation. MIG’s preference for DC positive polarity is a vital aspect of its operational effectiveness, setting it apart in this question.