i have heard that the smell you get from welding in stainless steel is caused by the stainless steel producing O3, ozone when it gets heated up, and
thats the reason you use argon on it when doing this..
but its only when the chrome is being completely burnt off..
i would like to have checked up on this, to see if other sources would state the same or something alike, but....
searching chrome and ozone just doesnt really get me any answers as it refers to some browsers..
im sorry if this is already basic knownledge, but i havent ever heard about this before, also this apparently only accours when you let the chrome get
air (oxygen)
it could possibly be making O2 into O3..?
if this havent been tried before i could easily see tonnes of possibilities with this, obviously H2O2 as a primary target for O3 production12AX7 - 3-3-2013 at 10:17
The UV from arcs is notorious for producing ozone. Occam's razor!
TimFantasma4500 - 3-3-2013 at 11:47
well that gives me a better understanding of how this is possible.. couldnt really understand how just hot chrome would make ozone.. (:
seems that it wont be that useful if you need a very strong light to sort of trigger this reaction..AndersHoveland - 3-3-2013 at 14:53
The reaction between chromate and acidified hydrogen peroxide does produce a small portion of ozone. It might be possible that small ammounts of
chromium oxides at high temperatures could be catalyzing the conversion of some of the oxygen into ozone.
[Edited on 3-3-2013 by AndersHoveland]Fantasma4500 - 3-3-2013 at 22:41
never thought a metal like chrome would have such properties.. what if you poured liquid oxygen over chrome?? doubt anybody have tried it, tho.. ill
put that on a list of stuff i should try if i acquire liquid oxygen some day.. (:AndersHoveland - 3-3-2013 at 22:46
Substitute platinum for your chromium and you're getting warm . . .
Platinum is a catalyst that decomposes O3...hissingnoise - 4-3-2013 at 02:54
It can also generate O3 ─ in a surface reaction; when a Pt wire, heated to redness, is dipped into LOX and retracted ozone
is produced at the metal surface . . .
Just another lab curiosity!
Fantasma4500 - 4-3-2013 at 08:56
i know platinum have highly valuable catalysing effects.. but chrome?? i see it as a in between cheap and pricey metal..
if you could somehow get a really good control on the heat of a little bit of chrome with large surface area per weight (electrically controlled?)
then it shouldnt be that hard to collect the O3..
could it be that there havent been looked very much into the possibilities of chrome metal?hissingnoise - 4-3-2013 at 10:53
I've welded SS with TIG without ever smelling ozone . . . ?Fantasma4500 - 5-3-2013 at 11:25
I've welded SS with TIG without ever smelling ozone . . . ?
well, i dont know if i can explain that.. or well not really, perhaps the argon which is usually used might of completely blocked the reaction? theres
usually a very special smell when welding in stainless steel (and apparently also when smelling a a solution of iron chrome and nickel chloride by
electrolysis of HCl with steel anode)
i was explained that the actual danger and the reason welding in steel is dangerous / toxic is because of the formed ozone.. i thought before it was
because of chrome and nickel molecules in air..
perhaps TIG doesnt splatter around the steel enough to cause this reaction??gregxy - 5-3-2013 at 12:34
Argon is used as a shield gas when welding to prevent
the oxygen in the air from oxidizing the metal and ruining
the weld. Argon is used when welding Ti, Al, stainless steel,
or when ever you want a high quality weld.
People say not to weld galvanized steel (which is zinc coated).
I'm not sure why zinc does not seem much more toxic than
other common metals. violet sin - 5-3-2013 at 12:52
Metal fume fever results(or can result) from welding galvie pipe w/o propped precautions. As I understand it, several metals can do that to ya.Fantasma4500 - 6-3-2013 at 12:14
oh yes.. i believe i have heard something about zinc being toxic somehow, as in when welding in it, but i heard it as the risk is when you use CO2
welder and not specifically welding in zinc, but it was rather a part of the wire you use for welding with.. could be wrong, very easily..
but exactly that it prevents it from oxidizing, and perhaps its also before they knew of the effect preventing too much ozone from forming?12AX7 - 9-3-2013 at 09:30
You also want to avoid volatile metals (Mg, Zn, and alloys containing them, like brass and most bronzes, which contain Zn), because the metal boils
off, contaminates the tungsten electrode, and condenses when it reaches cool air, making an aerosol that can cause metal fume fever. The aerosol
probably oxidizes as well, resulting in fine particles of oxide, or at least oxide-coated metal.
Stick welding galvanized steel isn't too bad (the zinc vapor acts like more cover gas, and it looks cool burning off ), but you have to do it outside, in a good breeze.
I don't think MIG welding would have too much trouble either, but the CO2 gas may be partly reduced to CO, which if it doesn't burn off, can cause
obvious problems in a poorly ventilated area.
TimFantasma4500 - 9-3-2013 at 16:44
didnt even think about CO2 reduction to CO..
offtopic: actually think the way that zinc burns was what started my interest in chemistry
generally heating metals up really quickly, adding in some unfamiliar gasses and even more different metals is quite uncontrolled giving various
different effects and potentially health effects..
so many possibilities in just heating up some metals when you get to think about it..vmelkon - 11-3-2013 at 12:36
For the original post, if you are talking about arc welding, you get ozone whenever you have a spark + air. You also get a few oxides of nitrogen such
as NO2. The UV light also generates ozone.
The argon gas is there to prevent oxidation of the metal. Very simple. I think we can all understand that.
There are some gas bottles that are a blend of argon and CO2. My brother rented one and did work on this car. The only difference is that it is
cheaper and is fine for steel welding.
If you want ozone, get some H2SO4 and a couple of good electrodes. I used lead. On the anode side, you get oxygen and I also smelled some ozone.Fantasma4500 - 11-3-2013 at 14:35
interesting.. are you sure it wasnt just by the electricity interfering with the oxygen in the air or something alike? as i know its made when
electricity runs through air (such as thunder..) violet sin - 11-3-2013 at 17:17
check out the library for atboic: "a text book of inorganic chemistry: vol 7 book i (of iii)" starting page 138 for ozone. it talks about the
sulfuric acid electrolysis way a little. and more info isn't that hard to find. Fantasma4500 - 12-3-2013 at 06:07
ive read through a few articles and they suggest that its not worth it with the sulfuric acid, tho..
starting point of the thread was to hear if Cr would even be capable of creating ozone somehow, which it apparently is.. im hopefully soon getting
some high conc. H2SO4 home, i believe when you shortcut a computer etc. when electricity breaks and you get some sharp kinda metallic smell thats
ozone? thats what i have been told.. i might get to do it, as i might try creating some (NH4)2S2O8 by electrolysis of H2SO4 and (NH4)2SO4
and by doing that i could try and see if any ozone is generated by smell, but as i see it takes fine adjustments to the electrical energy delivered to
create ozone and not oxygen
dont know if these things for aquariums would be of much if any use at all when talking about leading ozone into water to get H2O2 (which luckily can
be boiled down) to then create your own pure H2O2 of whatever concentration you might want..hissingnoise - 13-3-2013 at 02:49
Quote:
. . .starting point of the thread was to hear if Cr would even be capable of creating ozone somehow, which it apparently is..
I thought the thread had established that Cr has no part in ozone generation . . . All electrical discharge in air is capable of producing ozone and nitroxides!
The amounts produced by a welding arc may be tiny but, IIRC, ozone is detectable by smell in parts per billion . . .
Fantasma4500 - 13-3-2013 at 05:22
perhaps it might have been the electricity which ofcourse playes a role in welding, that might have split the oxygen into ozone, but apparently this
effect doesnt happen with ordinary iron (or steel, iron and graphite)
and as ive been told its the chrome thats giving the reason for the ozone being formed
just seems weird to me that chrome should be specifically good at this compared to iron or other industially used materialshissingnoise - 13-3-2013 at 05:51
Quote:
. . . and as ive been told its the chrome thats giving the reason for the ozone being formed.
Well, you've been told wrong!
And furthermore, ozone is thermally unstable and cannot exist at temps above 100°C!
