What surface treatment might improve fatigue resistance in sheet metal?

Using a smooth surface finish enhances fatigue resistance in sheet metal due to its ability to minimize stress concentrators on the metal surface. When metals are subjected to cyclic loading, surface imperfections can act as initiation points for cracks, which can lead to fatigue failure. A smooth surface reduces these imperfections, creating a more uniform distribution of stress across the sheet metal.

In contrast, other treatments might not provide the same benefits. For instance, coating with paint may offer corrosion protection but does not address the surface integrity regarding fatigue. Applying a rough texture can increase stress concentrations, which is detrimental to fatigue resistance, while leaving the surface untreated would not optimize the material’s performance under cyclic loads. Therefore, achieving a smooth finish is critical for maximizing the durability and longevity of sheet metal structures in applications subject to repeated stresses.