Official Answer
Answer
High-carbon steels like SAE 1070 to 1090 are susceptible to hydrogen embrittlement during acid pickling and electroplating processes (e.g., zinc or cadmium plating). Atomic hydrogen ($H$) diffuses into the crystal lattice, accumulating at grain boundaries and dislocations, which reduces ductility and leads to unpredictable brittle fracture under static load. To mitigate this, a 'Baking' process is mandatory. The springs must be baked at $375^{∘}F \pm 25^{∘}F$ ($190^{∘}C$) for at least $4$ to $24$ hours within $1$ hour of plating. Failure to bake results in 'delayed fracture', where the wave spring snaps hours or days after installation in a bore. In high-vibration automotive environments, this is a catastrophic failure mode.
