Which type of current is typically used for welding steel in GTAW?

In Gas Tungsten Arc Welding (GTAW), direct current is typically employed for welding steel due to its stability and efficiency in creating a strong, clean weld. Direct current provides a consistent arc which is essential for producing high-quality welds, especially on steel, as it allows for better control over the heat input and penetration.

The ability to precisely control the arc is pivotal when working with steel, as it helps to prevent overheating and distortion of the material. Additionally, direct current is well-suited for the use of a tungsten electrode and allows for the use of more significant electrode angles, making it ideal for various positions and types of joints.

While other types of current, such as alternating current, can be useful for welding materials like aluminum, they are not as effective for steel in the GTAW process. Pulsed current can also be beneficial in specific applications to control heat input and improve weld characteristics, but it is not the standard for general steel welding. Variable current may be used in advanced setups but does not define a prevalent approach in typical GTAW applications for steel.