Water/Oxide Staining on Duplex 2205

[innovation2]

Hi,

I am wondering if anyone has experienced staining on duplex 2205 HRAP coil? Take a look at the photo and let me know if this is typical of 2205. This is the second time we have run across this on coil product.

Thanks

 

[TomDOT]

Hm, was some carbon steel rubbed/dragged on your 2205? Carbon steel transfer would be a reasonable explanation.

 

[innovation2]

It is definitely not rust.

We have been told by the mill (Outokupmo) that it is an water stain created by the rinse after passivation when the coil is rolled. Essentially small amounts of oxide present in the rinse water.

Basically just wondering if anyone has ever had this experience with 2205 coil on their projects an

 

[TomDOT]

Of course the mill says that iron oxide on their product is definitely "not rust"

 

[EdStainless]

Not too uncommon in SS coil, all alloys.
If you are not pickling as part of your process then I would reject it.

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Plymouth Tube

 

[limey1]

I would check back with the mill, looking at the picture it seems a little too localized to be from rinsing. They should be rinsing with hot water, evaporation= minimized staining.

 

[Soln]

It looks like the plate was handled with vacuum lifting equipment. The ring is the seal of the suction cup. The same vacuum lift is probably used with mild steel material.