rusting in vacuum

[debashish]

can anybody tell me that does rusting can take place in vacuum. if yes then why or how. if no then why

[Severian]

No - rusting is oxidization. The iron bonds with oxygen in the air to form rust. In a vacuum there is no oxygen, so no rust.

[debashish]

can anybody tell me that does rusting can take place in vacuum??. if yes..........

consider a hollow metal cylinder/block of an automobile engine. the cylinder/block is air-tight and can be considered as vacuum when it is not in use for many days during rainy season. now if the outer region of the block i.e. the atmosphere contains moisture it wiil definately cool the metal cylinder/block which willl again affecf the temperature inside the cylinder/block. Now can these conditions slightly create rusting from inner surface of the cylinder/block????

[NeonBlack]

For the fuel to combust in the cylinder there needs to be oxygen which also creates rust so the inside is certainly not a vacuum.

[Kyrisch]

And if it was, the cylinder would implode.

[Kyrisch]

Ooh. Deja vu.

 

Why does everyone feel the need to post the same question twice?

[mezarashi]

I think NeonBlack may be right about the insides not being a vacuum. There is no reason for it to be so. The main point to make however is that rusting only occurs with iron. I'm pretty sure that the cyclinders are made of a more non-reactive metal alloy. In addition, there is ample lubrication present within the engine interiors. But lastly to answer your original question, I don't see why rusting could not happen in a vacuum given that somehow the water molecules and iron can sufficiently interact.

[Kyrisch]

Zero gravity and a vacuum are not the same thing. As long as oxygen is present, metal can rust, but in a vacuum, nothing is present, and therefore it is impossible for rust to occur. Remember that rust is simply the metal combusting at an extremely slow rate, and things need oxygen to combust.

[mezarashi]

Alright. This is confusing. I believe I corrected what I wrote, and now I find that there are two posts. I corrected it in anycase.

[YT2095]

Rusting, or more correctly the oxidation of Iron, can take place in a vacuum where Oxygen is present, it need not be in a gas form for this to take place.

 

Hmmm.. this thread(s) has been merged, and merged badly???? this post is #3

but still applicable.

[Kermit]

The main point to make however is that rusting only occurs with iron. I'm pretty sure that the cyclinders are made of a more non-reactive metal alloy.

 

I thought other metals could rust too, or at least become tarnished by reacting with oxygen?

[5614]

Metals can oxidise or react with oxygen yes, but only iron can rust.

[NeonBlack]

YT, even if the oxygen is in a liquid or solid phase there is still a certain vapor pressure of O2. Even if we ignore this, we still have a very low pressure if the oxygen is cool enough to be in a non-gasseous state.

At this extreme low temp and pressure I doubt any rusting reaction would be able to take place spontaneously.