Hydrogen Embrittlement is a catastrophic failure mode where hydrogen atoms infiltrate the crystal lattice of high-strength steel.
The Cause: It often happens during acid pickling or electroplating, where hydrogen is generated and absorbed by the metal.
The Danger: The trapped hydrogen increases internal pressure, causing the steel to lose its ductility. Under stress, the part doesn't stretch; it snaps suddenly like glass.
Prevention: Parts must be "baked" immediately after plating to drive the hydrogen out.