Skip to Main Content
Skip Nav Destination

Fracture of a cadmium-plated accumulator ring forged from 4140 steel was discovered during inspection and disassembly of a hydraulic-accumulator system stored at a depot. The ring had broken into five small and two large segments. The small segments of the broken ring displayed very flat fracture surfaces with no apparent yielding, but the two large segments did show evidence of bending (yielding) near the fractures. In addition, some segments contained fine radial cracks. Analysis (visual inspection, optical microscopy on polished-and-etched specimens, hardness testing, and chemical analysis) supported the conclusion that the failure was caused due to brittle fatigue, as evidenced by the intergranular nature of the fracture path. Also, hydrogen penetration occurred during the plating operation and was not relieved subsequently as required.

You do not currently have access to this chapter.
Don't already have an account? Register
Close Modal

or Create an Account

Close Modal
Close Modal