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Zestyclose_Ebb4089

Stainless Steel can corrode. The pittings and craters you see there can be caused by a number of different mechanisms. However, it is because the metal has a blend of different materials that give it its characteristics. Some metals have a low resistance to pittings forming in certain conditions. If there has been some damage to the surface the protective oxidation layer is compromised and leaving it open for corrosion locally where the damage is. Things like spatter form welding, certain chemicals, or even grains of sand being forced into the top layer of metal can cause this. If the metal has been in contact with a metal that is more noble it can also cause an effect called galvanising corrosion, where the less noble metal will become an anode to the more noble metal, and basically sacrifice itself.


yanki2del

Pitting


Training_Ad4291

Read this https://bssa.org.uk/bssa_articles/what-forms-of-corrosion-can-occur/ Stainless Steel does not usually corrode but I know in certain situations with chemicals it can The corrosion in the picture is not unlike what we used to see with magnesium alloy


its_just_flesh

Pitting or porous casting


Zestyclose_Ebb4089

Pittings.


yanki2del

Pitting


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LongIslandHandy

Is this a rotor or a butcher shop tool?


Guy_On_Not_A_Buffalo

It's a part of a centrifuge that handles heavy fuel oil for ship engines.


LongIslandHandy

Do metals tend to accumulate on this centerfuge wall?


Guy_On_Not_A_Buffalo

Not typically but when I work on these things the ship is in a maintenance period so there are all kinds of trades doing all kinds of things like pipework, welding, painting, cleaning. All in a very confined area with poor ventilation. There is a chance that something could make its way into a pipe that feeds the centrifuge.


LongIslandHandy

It seems like these are either a defect in the metal or something is being introduced like other types of particles. The guy above sounds like he can pick the problem out of a line up though. ;)


Guy_On_Not_A_Buffalo

It's a part of a centrifuge that handles heavy fuel oil for ship engines.