Which of the following materials typically requires pulsed MIG welding?

Pulsed MIG welding is particularly effective for welding thin materials like aluminum sheets because it helps to control the heat input and minimize warping or burn-through, which can easily occur due to aluminum's lower melting point. The pulsed process allows for a consistent heat input through alternating between high and low power levels, thus permitting the welder to deposit a controlled amount of filler material while maintaining a cooler base metal temperature. This is crucial for thin sections, as excessive heat can lead to defects such as porosity or distortion.

In contrast, thick steel plates and high carbon steels typically require higher continuous current levels for effective penetration and may not benefit as much from the pulsed technique. Cast iron components often need specialized welding approaches or filler materials more suitable for managing their unique properties, further separating them from the advantages of pulsed MIG on thinner materials like aluminum.