does corrosion of metal require oxygen?
458001
Yes it does. Corrosion is when the metal oxidises.
123326
Most corrosion is on the outside so it really doesn't make a difference, hot or cold. What determines corrosion is the \nenvironment outside of the pipe.
41970
ya, rusting is called "oxidation" because the iron reacts with the oxygen in the air to produce iron oxide:  Fe + O2 -> Fe2O3  iron oxide = rust.\n\nanyway, if you coat the iron with a film of something, the air can't get to the iron and voila, no rust!  this is also why things that rust are painted - paint does the same thing.\n\ni'm not sure how to answer the 2nd part of your question - doesn' make sense and to be honest, just doesn't jive with my experiences.  sorry!
348589
As the above answerer states, you don't need to - titanium won't rust; rather it develops a protective, inert oxide layer in air, just like aluminum has it's protective  inert oxide layer - Al2O3.\nIron and steel rust/oxidize in air and it can prevented by giving a coating of zinc, chromium, or magnesium on it.
734862
HgO ------> Hg + O2 at about 400 C\n\nMg + CuCl2 ---------->  MgCl2 + Cu(solid)\n\nMg, being higly electropositive than Cu, replaces Cu.
97708
the metal is simply not exposed to the outside oxygen - it is shielded from it by the paint, which itself contains little, if any oxygen
686818
stainless steel is rust proof anyway, to do this, zinc is added during the smelting process, this creates a coating over the metal and when it comes into conntact with oxygen and water it forms a clear oxide layer over the metal, hence stopping the steel from rusting
43302
Rust is the substance formed when iron compounds corrode in the presence of oxygen and water. It is a mixture of iron oxides and hydroxides. Rusting is a common term for corrosion, and usually corrosion of steel.\n\nIron is found naturally in the ore hematite as iron oxide, and metallic iron tends to return to a similar state when exposed to air, (hydrogen, oxygen, nitrogen, etc) and water. This corrosion is due to the oxidation reaction when iron metal returns to an energetically favourable state. Energy is given off when rust forms. The process of rusting can be summarized as three basic stages: The formation of iron(II) ions from the metal; the formation of hydroxide ions; and their reaction together, with the addition of oxygen, to create rust.\n\nIron is the main component of steel and the corrosion of steel is observed more frequently, since iron is rarely used without alloying in the present day.\n\nWhen steel contacts water, an electrochemical process starts. On the surface of the metal, iron is oxidized to iron(II):\n\n    Fe → Fe2+ + 2e-\n\nThe electrons released travel to the edges of the water droplet, where there is plenty of dissolved oxygen. They reduce the oxygen and water to hydroxide ions:\n\n    4e- + O2 + 2H2O → 4OH-\n\nThe hydroxide ions react with the iron(II) ions and more dissolved oxygen to form iron oxide. The hydration is variable, however in its most general form:\n\n    Fe2+ + 2OH- → Fe(OH)2\n    4Fe(OH)2 + O2 → 2(Fe2O3.xH2O) + 2H2O\n\nHence, rust is hydrated iron(III) oxide. Corrosion tends to progress faster in seawater than fresh water due to higher concentration of sodium chloride ions, making the solution more conductive. Rusting is also accelerated in the presence of acids, but inhibited by alkalis. Rust can often be removed through electrolysis, however the base metal object can not be restored through this method.\n\nHydrated iron oxide is permeable to air and water, meaning that the metal continues to corrode after rust has formed. The iron mass eventually converts entirely to rust, and disintegrates.
809009
The more reactive a metal, the greater tendency it has to form a positive ion in the context of a chemical reaction (e.g. Na => Na+ or Fe => Fe2+). This also implies that the reverse reaction becomes more difficult i.e. the more reactive a metal, the more difficult (and expensive) it is to extract from its ore and the metal is also more susceptible to corrosion with oxygen and water. \n\nTitanium, for example, has to be cast in a vacuum. \n\nActive metals once extracted and refined can then be hazardous - for example, lithium, sodium and potassium oxidise in the presence of water in a very exothermic reaction (causing fire/explosions!)
181750
Molecular oxygen is an oxidizing agent. Every molecule that is oxidized, requires an oxidizing agent. Molecular chlorine might work but is so corrosive that the plant would die.
410825
Others have had similar problems and solved them.  See the link.  In general, metals (especially iron and its alloys) rust when exposed to moisture in the presence of oxygen.  The rust is a loose collection of molecules that allow more moisture and oxygen to reach the base metal.  For example, you can shine aluminum but it will quickly dull with oxidation.  The aluminum corrosion however forms a tenacious film that protect the metal from additional corrosion.  I heard that copper (flashing?) on a rooftop can cause aluminum gutters to corode.  Various alloys of iron (steel) including heat treatments may impart various corrosion properties, however, chrome is usually added to form stainless steels that best resists rusting.  Silicon steel may have to be protected.  Good luck.
394719
Rust is a chemical reaction involving iron and oxygen.  Melting metal is simply a physical reaction changing the state of its matter, so melting the metal wouldn't get rid of the rust to the best of my knowledge.  IT might however make it easy for you to seperate the rusted and non rusted parts of the metal, but then again it might make it a total mess lol
431850
No.  A spark would require oxygen
1134239
When iron rusts it oxidizes.  New atoms are being added to the iron, so of course the mass would increase.  In a closed system, lacking oxygen, iron wouldn't rust, so the law of conservation of mass and energy still holds.  When a match burns, it's losing mass as energy in the form of heat; again the law of conservation holds.
408961
It depends on the impurities in the gas and the temperature of the gas.  If you have high chlorides and thermal cycling, you may need alloy steel.\n\nFor a pure hydrocarbon stream at less than 60°C, carbon steel would be fine.
734812
No, it is 5, water have to be oxidized in order to produce oxygen.
550059
Rust is the substance formed when iron compounds corrode in the presence of oxygen and water. It is a mixture of iron oxides and hydroxides. Rusting is a common term for corrosion, and usually corrosion of steel.\n\nIron is found naturally in the ore haematite as iron oxide, and metallic iron tends to return to a similar state when exposed to air, (hydrogen, oxygen, nitrogen, etc.) and water. This corrosion is due to the oxidation reaction when iron metal returns to an energetically favourable state. Energy is given off when rust forms. The process of rusting can be summarized as three basic stages: The formation of iron(II) ions from the metal; the formation of hydroxide ions; and their reaction together, with the addition of oxygen, to create rust.\n\nIron is the main component of steel and the corrosion of steel is observed more frequently, since iron is rarely used without alloying in the present day.\n\nWhen steel contacts water, an electrochemical process starts. On the surface of the metal, iron is oxidized to iron(II):\n\n    Fe → Fe2+ + 2e−\n\nThe electrons released travel to the edges of the water droplet, where there is plenty of dissolved oxygen. They reduce the oxygen and water to hydroxide ions:\n\n    4e− + O2 + 2H2O → 4OH−\n\nThe hydroxide ions react with the iron(II) ions and more dissolved oxygen to form iron oxide. The hydration is variable, however in its most general form:\n\n    Fe2+ + 2OH− → Fe(OH)2\n    4Fe(OH)2 + O2 → 2(Fe2O3.xH2O) + 2H2O\n\nHence, rust is hydrated iron(III) oxide. Corrosion tends to progress faster in seawater than fresh water due to higher concentration of sodium chloride ions, making the solution more conductive. Rusting is also accelerated in the presence of acids, but inhibited by alkalis. Rust can often be removed through electrolysis, however the base metal object can not be restored through this method.