[OT] rust & oxide

O

Orange

Guest
Could you tell me if this white thing is rust or something else:

http://home.drenik.net/orange/photo/rust/Set48_01.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_02.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_03.jpg (~50kb)

It turned red when I heated it with fan.
If you have any idea what it could be, please reply to:
orange@drenik.net
 
Hi Orange,

The white stuff is zinc oxide, it is from the galvanize plating
on the steel. The reddish brown stuff is plain old ferrous
rust.

Galvanize plating is used because as the galvanize corrodes, it
electrically protects the steel near it from corroding. This
piece of sheet metal has been exposed to damp/wet conditions that
has caused the zinc galvanize coating to corrode away (white spots)
enough to allow the steel under it to rust.

-Chuck

Orange wrote:
Could you tell me if this white thing is rust or something else:

http://home.drenik.net/orange/photo/rust/Set48_01.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_02.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_03.jpg (~50kb)

It turned red when I heated it with fan.
If you have any idea what it could be, please reply to:
orange@drenik.net
Click to expand...
 
Chuck Harris <cfharris@erols.com> wrote in message news:<3fd75beb$0$14975$61fed72c@news.rcn.com>...
Hi Orange,

The white stuff is zinc oxide, it is from the galvanize plating
on the steel. The reddish brown stuff is plain old ferrous
rust.

Galvanize plating is used because as the galvanize corrodes, it
electrically protects the steel near it from corroding. This
piece of sheet metal has been exposed to damp/wet conditions that
has caused the zinc galvanize coating to corrode away (white spots)
enough to allow the steel under it to rust.

-Chuck

Thanks for the reply, Chuck.
Click to expand...
Do you think that metal inside computer (excluding cover) is also
galvanized? It looks gray like ordinary iron.
Cover has strange colour something like benzine, thats galvanization,
right?


Orange wrote:
Could you tell me if this white thing is rust or something else:

http://home.drenik.net/orange/photo/rust/Set48_01.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_02.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_03.jpg (~50kb)

It turned red when I heated it with fan.
If you have any idea what it could be, please reply to:
orange@drenik.net
Click to expand...
 
Hi Orange,

I couldn't really say, there are several protective metal coatings
that are commonly used on steel:

1) tin (you would recognize it from tin cans)
2) galvanize (hot dipped in zinc, has a gray faceted appearance)
3) zinc electro plate (shiny, slight blue/gray cast)
4) zinc chromate (shiny, slight orange cast)
5) cadmium plate (shiny, bluish/gray cast)

And, of course, there are nickel plate, and chrome plate,
but they don't appear all that often in pc powersupplies.

I would guess zinc chromate.

-Chuck

Orange wrote:

Thanks for the reply, Chuck.
Do you think that metal inside computer (excluding cover) is also
galvanized? It looks gray like ordinary iron.
Cover has strange colour something like benzine, thats galvanization,
right?



Orange wrote:

Could you tell me if this white thing is rust or something else:

http://home.drenik.net/orange/photo/rust/Set48_01.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_02.jpg (~50kb)

http://home.drenik.net/orange/photo/rust/Set48_03.jpg (~50kb)

It turned red when I heated it with fan.
If you have any idea what it could be, please reply to:
orange@drenik.net
Click to expand...
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top