What condition indicates severe damage on a metallic surface?

Complete oxidation on a metallic surface indicates a severe level of damage because it signifies that the material has undergone extensive corrosion, which often compromises its structural integrity. When a metal is completely oxidized, it transforms from its original, strong metallic state into a weaker and less stable oxide form. This deterioration can lead to significant safety concerns, especially in applications like gas piping, where structural failure could lead to leaks or catastrophic events.

In contrast, conditions like light surface oxide, peeling and scaling, or minor surface blemishes suggest varying degrees of wear or surface treatment degradation but do not necessarily reflect the same urgency or severity as complete oxidation. These conditions might still be manageable through maintenance or repair, while complete oxidation usually necessitates more serious remediation efforts, such as replacement of the affected sections.