Although it is really too hard to answer from just the one photomicrograph, can you guess what happened ?
|
Here we have a leaded monel (70% nickel - 30% copper)
propeller shaft, shown at 500X. The etchant was Marble's
reagent. Although it is really too hard to answer from just the one photomicrograph, can you guess what happened ? |
| The shaft failed
by pitting corrosion in stagnant salt water (the pits can't be seen
here). The fatigue crack seen in the photomicrograph started at
stress corrosion cracks emanating from the pits. The lead
stringers cannot be distinguished in this
photomicrograph.
Go on to Lesson 4.
Return to Non-Ferrous Metals Introduction. |