Recently a heavy pitting corrosion issue was found on a integrally geared compressor. Below is a brief summary.
* pinion thrust collar
- The pitting corrosion was mainly happened on active side of pinion thrust collar
- A mild pitting corrosion also was found on inactive side of pinion thrust collar
* pinion gear surface
- A severe pitting corrosion was found at loading flank of pinion gear
- A mild pitting corrosion also was found at non-loading flank of pinion gear
Based on your experience, Is this mainly caused by :
1. lube oil degradation
2. High load on these loading surfaces, causing the surface fatigue failure (pitting)
3. Both item1 and item2
Thanks for your kind comments in advance.