4. Equipment cost and energy consumption: AC welding machines are cheaper, but energy consumption is higher; DC welding machines are more energy-saving, lightweight and easy to move.

5. Welding efficiency and quality: The welding efficiency and welding joint quality of DC welding machines are usually better than AC welding machines.

6. Use

AC welding machine: suitable for welding low carbon steel and alloy structural steels with low strength, as well as for use in occasions where too high welding quality and efficiency are not required.

DC welding machine: suitable for welding important structural parts, such as boilers, pressure vessels, etc., and when high-quality welds are needed. In addition, DC welding machines are also suitable for backward welding and vertical welding.

1. Current output method: The AC welding machine uses AC power, and the current direction changes periodically; the DC welding machine uses DC power, and the current direction remains unchanged.

2. Suitable welding materials: AC welding machines are usually used to weld low-carbon steel and alloy structural steels with low strength, using acid welding rods; DC welding machines are suitable for more important welding tasks, such as boilers, pressure vessels, etc., and use alkaline welding rods because alkaline welding rods have good crack resistance and mechanical properties at the weld after welding.

3. Welding performance: DC welding machines provide more stable arcs, less splashing, beautiful weld molding, and are suitable for welding thin parts; AC welding machines have poor arc stability, and the weld quality is not as good as DC welding machines.